Trauma - Diagnostics and Triage - uu .diva

ACTAUNIVERSITATIS

UPSALIENSISUPPSALA

2018

Digital Comprehensive Summaries of Uppsala Dissertationsfrom the Faculty of Medicine 1431

Trauma - Diagnostics and Triage

FREDRIK LINDER

ISSN 1651-6206ISBN 978-91-513-0242-3urn:nbn:se:uu:diva-341763

Dissertation presented at Uppsala University to be publicly examined in Enghoffsalen, ingång 50bv, Akademiska sjukhuset, 751 85, Uppsala, Friday, 13 April 2018 at 13:00 for the degree of Doctor of Philosophy (Faculty of Medicine). The examination will be conducted in Norwegian and Swedish. Faculty examiner: Professor Pål Aksel Naess (Institutt for klinisk medisin, Det medisinske fakultet, Universitetet i Oslo).

AbstractLinder, F. 2018. Trauma - Diagnostics and Triage. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1431. 75 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-513-0242-3.

Trauma is a leading cause of death worldwide and it reduces years of productive life and leads to disability. Effective trauma care relies on triage, which aims to ration the use of fine resources to patients with the greatest needs. Imaging is essential in the severely injured patient, but comes at a cost of radiation exposure, which could cause cancer in up to 1/1000 patients examined with whole body computed tomography.

Paper I showed that routine whole-body CT of high-energy trauma patients may lead to excessive radiation exposure without clinical benefit. There were no missed injuries in the low risk group and the mean injury severity score (ISS) was 0.84 in this group (standard deviation SD 1.57). Paper II surveyed radiologists at 93 Nordic and 10 non-Nordic hospitals with 23 questions on usage of whole body CT in trauma. The response rate was 62% and there were several differences in criteria, protocols and radiation dose. Most, 89% consider there is a need for national/international guidelines. Paper III evaluated compliance with trauma alert criteria with the aim to describe how resources may be optimized with sustained low undertriage. The compliance with full trauma alert and no trauma alert was 80% and 79% respectively. Compliance with limited trauma alert was only 54%, and prehospital immobilization was an independent risk factor for mistriage with an odds ratio of 1.78 (95% CI 1.42 - 2.23). Paper IV demonstrated that the newly implemented Swedish trauma team activation (TTA) criteria result in a reduction in limited TTA frequency, indicating an increased efficiency in use of resources. The over- and undertriage is unchanged compared to former criteria, thus upholding patient safety.

In conclusion, whole body CT in trauma should be used only in patients with clinical findings. The routines for use of whole body CT in trauma differ between institutions, and efforts to establish common guidelines are requested. Better compliance with alert criteria may optimize resource allocation, and the newly implemented national TTA criteria in Sweden are safe and resource efficient.

Keywords: wounds and injuries, trauma, triage, whole body computed tomography in trauma, compliance, radiation exposure, CT, radiation safety

Fredrik Linder, Department of Surgical Sciences, Akademiska sjukhuset, Uppsala University, SE-75185 Uppsala, Sweden.

ISSN 1651-6206ISBN 978-91-513-0242-3urn:nbn:se:uu:diva-341763 (http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-341763)

To Louise, Ella, Agnes and Gunnar

List of Papers

This thesis is based on the following papers, which are referred to in the text by their Roman numerals.

I Linder F, Mani K, Juhlin C, Eklöf H. (2016) Routine whole body

CT of high energy trauma patients leads to excessive radiation exposure. Published in Scand J Trauma Resusc Emerg Med. Jan 27;24(1):7

II Wiklund E, Koskinen SK, Linder F, Åslund PE, Eklöf H. (2015) Whole body computed tomography for trauma patients in the Nordic countries 2014: survey shows significant differences and a need for common guidelines. Published in Acta Radiol. 2016 Jun;57(6):750-7.

III Linder F, Holmberg L, Eklöf H, Björck M, Juhlin C, Mani K. (2018) Better compliance with triage criteria in trauma would re-duce costs with maintained patient safety.

Epub ahead of print in Eur J Emerg Med. 2018 Feb 12

IV Linder F, Holmberg L, Björck M, Juhlin C, Thorbjörnsen K, Wisinger J, Polleryd P, Eklöf H, Mani K. (2018) A prospective stepped wedge cohort evaluation of the new national trauma team activation criteria in Sweden – the TRAUMALERT study.

Manuscript.

Reprints were made with permission from the respective publishers.

Contents

Introduction ............................................................................................... 11History .................................................................................................. 11Wartime experience .............................................................................. 12

World War I ..................................................................................... 12World War II ................................................................................... 14The Vietnam War ............................................................................ 15

Background .......................................................................................... 15Implementation of Advanced trauma life support (ATLS®) ........... 15Transfusion protocols ...................................................................... 16Damage control surgery ................................................................... 16Radiology ......................................................................................... 17Use of CT in trauma care ................................................................. 19Triage ............................................................................................... 20The trauma teams ............................................................................. 22The injury severity score ................................................................. 23The new injury severity score .......................................................... 24Over- and undertriage ...................................................................... 24National consensus based trauma team activation criteria .............. 26

Aims .......................................................................................................... 28

Patients and Methods ................................................................................ 29Paper I .................................................................................................. 29Paper II ................................................................................................. 30Paper III ................................................................................................ 30Paper IV ................................................................................................ 31Statistics ............................................................................................... 31Ethical considerations .......................................................................... 32

Results ....................................................................................................... 35Paper I .................................................................................................. 35Paper II ................................................................................................. 37Paper III ................................................................................................ 40Paper IV ................................................................................................ 42

General discussion .................................................................................... 46Whole body computed tomography ..................................................... 46

Triage ................................................................................................... 47AIS-scoring and triage bias ............................................................. 50

Ethical considerations .......................................................................... 51Compliance to alert criteria .................................................................. 51The seasonal distribution in trauma ..................................................... 52The Swedish Trauma Registry ............................................................. 53

Conclusions ............................................................................................... 55

Future perspectives ................................................................................... 56Use of WBCT in trauma .................................................................. 56Evaluation of specific TTA criteria ................................................. 56Validation of SweTrau ..................................................................... 56Using the TTA criteria for pre-hospital triage? ............................... 57The use of spinal immobilization .................................................... 57

Sammanfattning på svenska (Summary in Swedish) ................................ 58Delarbete I ............................................................................................ 59Delarbete II ........................................................................................... 60Delarbete III ......................................................................................... 60Delarbete IV ......................................................................................... 61

Acknowledgements ................................................................................... 62

References ................................................................................................. 64

Appendix ................................................................................................... 69

Abbreviations

AAAM ACS-CoT

Association for Advancement of Automotive MedicineAmerican College of Surgeons Committee on Trauma

AIS ALARA-principle

Abbreviated Injury Score As Low As Reasonably Achievable principle

ATLS CT DLP ED

Advanced Trauma Life Support Computed Tomography Dose Length Product Emergency Department

FAST Focused Assessment with Sonography in Trauma FFP Fresh Frozen Plasma GSW Gunshot Wound ICU Intensive Care Unit ISS Injury Severity Score MOI Mechanism of Injury MTP Massive Transfusion Protocols MVC Motor Vehicle Crash NISS New Injury Severity Score PRBC Packed Red Blood Cells SIR SOP

Swedish Intensive-care Registry Standard Operating Procedures

STRADA Swedish Traffic Accident Data Acquisition SweTrau TTA WBCT WWI WWII

Swedish trauma registry Trauma Team Activation Whole Body Computed Tomography World War I World War II

Introduction

Trauma is a leading cause of death in Sweden for young adults between 15-44 years1. Worldwide, trauma is a health problem with great magnitude that shortens life expectancy as well as productive life and leads to disability. The financial costs are high and it has been estimated that 25% of all emergency department (ED) visits is Sweden are due to trauma and these patients con-sume almost 1.000.000 days of hospitalization every year. A leading cause of trauma is motor vehicle crashes (MVC) with 1.25 million yearly deaths world-wide. About 90% of these fatalities occur in low- and middle-income countries even though these countries have only half of the world´s vehicles2. The changes in the number of road traffic deaths by income status shows that low-income countries have an ever-increasing death toll and high-income coun-tries have a decreasing death toll.

Despite the recent decrease of MVC in high-income countries such as Swe-den, other mechanisms of injury (MOI) are more constant in prevalence and result in morbidity, disability, mortality and major costs.

To meet this challenge, the development of a comprehensive trauma organ-ization has been the focus of trauma care over the last decades. This includes effective and competent pre-hospital life support. Structured transport algo-rithms in place where hospitals are bypassed in order to deliver highly spe-cialized trauma care at trauma centers with a high concentration of medical resources. At the trauma centers care is often provided using the ATLS® sys-tem and guidelines, and data is reported to registries following the Utstein style data recommendations3, such as the Swedish trauma registry (SweTrau), for research- and developmental purposes. Effective trauma care relies on tri-age, which aims to ration the use of fine resources to patients with the greatest needs, prompt diagnosis of life threatening pathologies with clinical examina-tion and imaging, and diligent delivery of surgical care when needed.

History Dominique Jean Larrey (1766-1842) has been described as the father of triage and modern military surgery. He developed a plan for rapid evacuation of wounded soldiers from the battlefield using ambulances volantes (“flying am-bulances”). These carriages with two horses were the pioneers to ambulances of today and provided transport to care for all combatants, regardless of rank

or nationality. Larrey´s sanitary system, surgical mastery and dedication are even considered a key factor in the success of Napoleon Bonaparte′s cam-paigns and battles. Before the introduction of the ambulances volantes the wounded were left in field until the engagement was over, and if they were not captured or killed by enemy soldiers, the delay of 24-36 hours rendered casualties for conditions that would be salvageable if treated urgently4.

The system of rapid evacuation during battle to medical care boosted mo-rale among soldiers and was also a part of an early triage protocol where the medical needs of the patient had priority. Larrey established triage rules that were over a century before it´s time:

…those dangerously wounded must be attended first entirely without regard

to rank or distinction and those less severely wounded must wait until the gravely hurt have been operated and addressed. The slightly wounded can go to the hospital in the first and second line, especially officers, because the of-ficers have horses.5

Dominique Jean Larrey was truly a great trauma surgeon and even with his

many contributions to surgical care including wound management, limb am-putation, effective control of hemorrhage, drainage of hemothorax and pack-ing of sucking chest wounds, Napoleon Bonaparte expressed his amazement of the results of Larrey´s sanitary system with the words:

Your work is one of the greatest conceptions of our age and alone is suffi-

cient to ensure your reputation.6, 7

Wartime experience World War I A major leap in the advances of surgery was made during World War I (WWI). The development of surgery at the front with motorized ambulance services and the implementation of x-rays as a diagnostic tool improved the outcomes. Triage was implemented in the trenches and at casualty clearing stations lo-cated only a few kilometers from the enemy line. The overwhelming number of injured soldiers and their needs contributed to improve surgical care in a time of despair and insufficiency. Operations performed at a single casualty clearing station during a few months’ time with heavy fighting is compiled in table 18.

Table 1. Operations performed at a casualty clearing station

Ligature of arteries: Amputations:

Carotid 5 Shoulder joint 14 Vertebral 2 Upper arm 77 Subclavian 2 Forearm 31 Axillary 15 Thigh 186 Brachial 39 Knee 10 Radial 18 Leg 76 Ulnar 8 Ankle 6 Ext. iliac 2 Various 31 Femoral 51 431 Popliteal 31 Ant. tibial 16 For drainage of pleura 49 Post. tibial 58 For wounds of the abdomen 106 Various 30 Removal of testis 33

277 For ruptured urethra 9 For treatment of fractures: Enucleation of eye 43

Skull 189 Plastic operations 33 Vertebrae 18 Tracheostomy 17 Humerus 298 280 Forearm 133 Excision and cleansing of wounds: Femur 299 Head and neck 95 Leg 309 Trunk 309 Jaws 38 Upper limb 249 Various 119 Lower limb 765

1403 Multiple 398 For treatment of joints: 1816

Knee 183 For conditions not due to gunshot wounds: Other joints 64 Appendicitis 34

247 Strangulated hernia 1 Cellulitis 53

Various 13 101

In total 4,554 surgical operations at a casualty clearing station. Total number of wounded ad-mitted: 20,5898

Even with the improvements in transporting the patients from the battlefield to the primary surgical facilities, a consecutive series of abdominal wounds show the time of evacuation to casualty clearing station was inadequate. Only 24 out of 200 patients reached the clearing station within 3 hours, and 66 did not reach it within 12 hours. The treatment for abdominal gunshot wounds (GSW) went from conservative, with a mortality rate of 70-80%, to an active approach with laparotomy for all GSW and an outcome of about 50% mortal-ity. Thus, surgical care with early laparotomy seemed to improve outcome and decrease mortality by 15-20%.8

The practice is now to operate on all cases unless there is some reason to the contrary, and to operate on principle rather than on the indications by symp-toms.

Still, the outcome seemed to be related to the time from injury to the oper-ating theatre, with a worsening of outcome if operation was undertaken later than 12 hours after injury. An operating theatre at a casualty clearing station is shown in figure 1.

Vascular repair was seldom undertaken mainly due to retraction of blood vessels and substance deficit that made primary suture impossible.

Figure 1. Operating theatre at casualty clearing station where one senior surgeon could oversee three junior surgeons and triage the needs of the patients

World War II Advances in trauma care were once again accelerated as the world fell into the global conflicts of World War II (WWII). The works of DeBakey and Sime-one with an analysis of 2,471 arterial injuries described the advances in trauma and vascular surgery. Bernheim, who went to many fronts of war with his own elaborate equipment for surgical use, concluded that even with the advances made in vascular repair with synthetic grafts, vein grafts or direct suture, the lack of supportive tissue and the time required to do an arterial repair made reconstructive vascular surgery unjustifiable. He remarked:

Only a foolhardy man would have essayed suture of arterial or venous

trunks in the presence of infections such as were the rule in almost all the in-jured. 9

In total, out of 2,471 cases, only 81 suture repairs were performed and the method of choice was ligation with 1,639 cases. The amputation frequency was about 50%. Patients treated with primary repair were highly selected, but it was showed that amputation rates decreased to about 30% with primary re-pair.10

The Vietnam War In the Vietnam War the tables had turned. During the World Wars, ligation was the method of choice for vascular injury. Amputation rates were about 50%, and patients treated with direct repair or venous graft were few.

Dr Norman Rich initiated the Vietnam vascular registry, and in an analysis of 1000 cases only 15 were treated with ligation. 45.9% were treated with autogenous vein graft and 37.7% with primary end-to-end anastomosis. The amputation rate was 12.8%.11

Background Implementation of Advanced trauma life support (ATLS®) The advanced trauma life support (ATLS) concept was originally developed in Nebraska, USA, in 1978.12 It followed after the tragic plane crash in 1976 where Dr Jim Styner, an orthopedic surgeon, was seriously injured along with three of his children. One child suffered minor injuries, and his wife was in-stantly killed. After inadequate care by today’s standards, he said:

When I can provide better care in the field with limited resources than what

my children and I received at the primary care facility, there is something wrong with the system, and the system has to be changed.

After 2 years of local courses the American college of surgeons committee

on trauma (ACS-CoT) introduced an updated version in the USA and other countries. In 1986 several countries in South America joined in, and the course was given for the first time in Sweden in 1996. It has now been taught to over 1 million doctors in more than 50 countries, and has become a key component in care for traumatically injured patients. It is a language in trauma care, using a multi-disciplinary and evidence based approach.13

The ATLS program is one way to provide for the trauma patient and to manage injuries. It teaches the basic skills necessary to:

1. Assess the patient’s condition, both accurately and rapidly 2. Prioritize, Resuscitate and Stabilize 3. Decide which patients need to be transferred 4. Arrange transports according to who, what, when, and how

5. Make sure optimum care is provided, and that it does not deteriorate any time during the primary and secondary survey13

Transfusion protocols In the beginning of the 20th century transfusions to restore blood volume was sometimes given intravenously with saline. More often rectally and the method of choice was per oral administration8. In the 1920´s transfusion of whole blood was used alongside volume replacement with saline, and this practice continued until the decades after WWII when whole blood fractiona-tion techniques opened up for more targeted transfusions while limiting the risks for transfusion reaction and infections.14

Component therapy has become the standard of care from the 1970´s, and on. Studies on effects of component therapy compared to whole blood trans-fusions have been performed15, but not on trauma patients with needs of mas-sive transfusion.

After the second Gulf War military use of whole blood had indicated less coagulopathy in severely injured patients and in a civilian practice the use of fresh frozen plasma (FFP) and its ratio to packed red blood cells (PRBC) was studied with findings that the FFP:PRBC ratio close to 1:1 in the patient re-quiring massive transfusion had a survival advantage.16

The development of massive transfusion protocols (MTP) has not only en-sured the correct ratios on blood components, but also put the light on hypo-thermia and its role in coagulopathy, the availability of blood components, the use of fibrinogen, and the need for rapid surgical intervention to stop the bleeding.

Damage control surgery The damage control concept originates from naval history, where the captain would set the damaged ship on ground in order to prevent it from sinking. This was used during the attacks on Pearl Harbor in 1941 with success. The stranded ships could be repaired and reused.

In 1983 H. Harlan Stone described a case series of 31 patients with onset of major coagulopathy during laparotomy17. The first 14 patients were man-aged with standard hematologic replacements during laparotomy and only one patient survived. The following 17 patients had their laparotomy terminated as quickly as possible, without restoration of GI continuity, and with packing of the abdominal cavity. 11 patients in this group deemed to have lethal coag-ulopathy survived.

In 1993, the concept of “Damage control” surgery was introduced by MF Rotondo and CW Schwab in their landmark paper “Damage control': an ap-proach for improved survival in exsanguinating penetrating abdominal in-jury.”18 They described the concept in a surgical context:

A deliberate and preemptive set of non- traditional resuscitative and surgi-cal maneuvers to reverse the pre-terminal effects of exsanguinations, massive injury or septic shock. The priority of DC is to save life.

The prior works of H. Harlan Stone, articles on abdominal packing for liver hemorrhage, and the works of WWI surgeons such as Bernheim, Makins and Captain Hay in a way all described the concepts of damage control surgery. Ligate vessels instead of spending time on repair with continuous blood loss. But MF Rotondo and CW Schwab re-launched the concept in a civilian con-text where they showed that the most injured patients could benefit from it.

Today, Damage control surgery is part of every trauma surgeon’s toolbox to deal with the exsanguinating patient.

Figure 2. Second look, 48 hours after damage control laparotomy in a previously ex-sanguinating trauma patient.

Radiology The use of plain radiographs to map foreign bodies in penetrating trauma was introduced during the Abyssinian War of 1896 and was widespread during

WWI19, 20. It was of great help in deciding operative approach and approxi-mating fractures. It was later further developed by the introduction of intrave-nous contrast medium to depict blood vessels and per-oral barium contrast media to follow the contingency of the gastrointestinal tract8, 21.

The introduction of ultrasonic Doppler devices enhanced diagnostics on vascular injuries and the introduction of ultrasonography to diagnose free flu-ids intra-abdominally was later adapted for trauma care in the use of ultraso-nography in the focused assessment with sonography in trauma (FAST)22, 23.

The major radiological breakthrough in trauma care and diagnostics for trauma is the widespread use of Computed Tomography (CT)24, 25. If only one achievement in refining trauma care was mentioned, CT is at the top of the list. The Austrian mathematician Johann Radon invented the theory behind computed tomographic reconstruction in his mathematic construction that he called the Radon Transform26. Sir Godfrey Hounsfield constructed the first commercial CT-scanner, and it was installed and used at Atkinson Morley hospital, London, in 197227. It took about 2 ½ hours to process the images by computer and the resolution was 80x80 pixels. Hounsfield and Cormack shared the 1979 Nobel prize in medicine for their inventions.28

Figure 3. Sir Godfrey Hounsfield´s sketch of the principles of a computed tomogra-phy.

Use of CT in trauma care The CT-scanners performance improved during the 80´s, and in the early

90´s CT-scans of the head, neck, thorax and abdomen were implemented in the treatment algorithms for multi-trauma patients if they were hemodynami-cally stable.29 Sweden was an early adopter of this concept, and this routine was followed by the aim to standardize CT examinations for multi-trauma pa-tients.24 Most institutions implement the algorithm of a topogram followed by a native head and neck scan, intravenous contrast injection and the thorax, abdomen and pelvis scan in venous phase. Another topogram is done after 5 minutes in excretion phase. Some institutions also include a scan of the thorax; abdomen and pelvis in arterial phase or use a mixed bolus technique. The ex-position to ionizing radiation is a factor to consider especially in the young patient examined with whole body computed tomography in trauma (WBCT), and over time the use of WBCT in trauma is increasing30-32. The role of CT in trauma has developed over the last decades, and most studies have found it valuable and accurate33. The use of WBCT in the multi-trauma patient reveals occult injuries when compared to selective CT-scans, but the clinical benefit is topic for discussion34. The effect of WBCT during trauma resuscitation was found beneficial in a retrospective, multicenter analysis35. The proportion of blunt/penetrating trauma is a factor to consider because the operative needs for patient subject to penetrating trauma is higher. In the European countries, the proportion of penetrating trauma is about 10%, thus the need for urgent surgery is less predominant36. Many studies derive from North America, and the injury patterns are not the same, and conclusions must therefore be drawn judiciously. Could the use of WBCT in trauma be omitted in patients without clinical findings suggesting injury? There have been some studies suggesting a clinical prediction rule to safely omit WBCT in trauma37. In paper I, we aimed to study how WBCT was used in a Nordic setting in a small and large hospital, and if we could retrospectively identify patients who did not benefit from WBCT.

Figure 4. The logistics in WBCT of a trauma patient during an exercise.

Over the last decades, and even today, there is an ongoing discussion on when, where and how to perform WBCT. These issues were addressed in a survey in the Nordic countries 2014, presented in paper II.

Triage The “Golden hour” in trauma was first introduced in 1975, as a concept in trauma care where it was hypothesized that time from injury to definitive care was a key factor to keep short in order to decrease mortality38. D.D Trunkey suggested the trimodal death distribution in 1983 to describe the time intervals from injury to death39. Later studies have shown that the distribution of trauma deaths occurs at a quicker rate than previously reported, because declaration of death is not done until resuscitative measures have been taken thus prolong-ing the time from injury to declaration of death40, 41. The severely injured pa-tient benefits the most from rapid assessment and treatment, and patients who are not severely injured are able to withstand a prolonged time from injury to definitive treatment.

This is the basis for field triage; to identify patients with the greatest needs and prioritize them for treatment and transport42. Transport of the severely injured patient to a trauma center improves survival compared to a non-trauma center43.

In this thesis focus is on the use of in-hospital triage and allocation of re-sources within the trauma center, and much of what is valid in field-triage, also apply in a hospital setting. The principles of triage are stated in the ACS-CoT report Resources for optimal care of the injured patient44. In a two-tier triage system, full trauma team activation is based on deranged physiology such as loss of airway, hypotension, tachycardia or reduced Glasgow coma scale, and/or type specific injuries such as penetrating injuries to the torso, pelvic fractures, paralysis or amputation proximal to wrist or ankle.

Limited trauma team activation is based on mechanism of injury where MVC is a major contributor. High fall injuries are the other major mechanism that activates a limited trauma team.

The presence of impaired physiology in itself, or in combination with type specific injuries is highly sensitive for serious injury defined as Injury severity score (ISS)>1545. Mechanism of injury has in several studies shown increased sensitivity in correctly identifying the severely injured patient only slightly and at the same time to decrease specificity substantially46-48.

Over- and undertriage are factors that should be monitored, and it has been suggested that an overtriage of 25-35% is acceptable in order to keep under-triage <5%44.

The authors are convinced that mechanism of injury alone is an inferior predictor for serious injury. MVC in the Nordic traffic environment with safe cars and roads are seldom the cause for severe injuries. The common use of long spine-boards for immobilization decreases compliance to alert criteria.

Figure 5. Multidisciplinary approach of the trauma team during primary survey.

The trauma teams When a full trauma team activation (TTA) is initiated, the hospital mobilizes staff to gather in the emergency department and prepare for initial assessment when the patient arrives. The TTA require doctors and nurses to discontinue with their regular tasks and to go to the trauma bay in the ED as soon as pos-sible. If a team member is unable to attend, the alert is forwarded to another employee with the specific qualifications required. The team preparations are supervised by the trauma leader, and the radiology department and operating theatres are informed their services may be needed.

The team consists of the trauma leader, surgeon on call, anesthetist, ortho-pedic surgeon, radiologist and six nurses including a radiology nurse and an anesthetist nurse. At a University hospital a neuro surgeon, thoracic surgeon and vascular surgeon may also be a part of the trauma team as well as several more anesthetists. It is not uncommon with 17 doctors and nurses present at a full TTA.

The limited TTA gathers a small team with two ED nurses and the surgeon on call. A consultant trauma surgeon and the radiology department are notified of the limited TTA but their presence is not mandatory. The main difference between a limited TTA and regular trauma care where no TTA has been initi-ated is in timely resource allocation. A TTA takes precedence over every other patient at the ED except for ongoing resuscitation.

The injury severity score In 1974, Dr Susan Baker, an epidemiologist at the Association for Advance-ment of Automotive Medicine (AAAM) introduced the Injury Severity Score49, 50. The correlation between the severity of an injury and mortality was not linear but rather exponential which was shown in this groundbreaking work. The ISS is based upon the Abbreviated Injury Scale (AIS)51 published in 1971 where every injury is given a score between 1 (minor) and 6 (lethal). The AIS has been updated several times, and in this thesis we used AIS 2005, rev. 200852.

The ISS is calculated by compartmentalizing the human body into nine body regions: Head, Face, Neck, Thorax, Abdomen/pelvis, Spine, Upper ex-tremities, Lower extremities and External. The injuries in every region is cat-egorized using AIS and given a score between 1-6. Only the most severe injury in every body region is chosen and squared giving a score between 1-25. The three most severe injuries are added into the ISS resulting in a score between 0-75. If an injury is scored as 6 by the AIS it automatically results in an ISS of 75. The ISS has been used in more than 3,600 articles listed on PubMed (Boolean search phrase “injury AND severity AND score AND iss”) and re-main the golden standard in injury severity scoring.

Figure 6. The original figure showing the exponential increase in mortality with a more severe injury49.

The new injury severity score The ISS does not compensate for the fact that there can sometimes exist mul-tiple severe injuries within the same body region. This is often the case in penetrating injuries where one body region, for instance the abdomen, can sustain severe injuries to i.e. liver, vena cava, stomach and spleen. The AIS for these injuries could be liver-3, vena cava-5, stomach-3 and spleen-4. The ISS for this patient would be 25, but the New Injury Severity Score (NISS)53 uses the three most severe injuries regardless of body regions and would in this case result in 32+42+52=50. The maximum score of NISS is 75 and it re-sembles ISS in all other aspects apart from the use of body regions.

The NISS was introduced in 1997 and has been used in 175 articles (Bool-ean search phrase “new AND injury AND severity AND score AND niss”). The accuracy in predicting mortality with the NISS has been studied in a sys-tematic review54 and found to be similar to the ISS but it can be deemed infe-rior to ISS in blunt trauma.

Over- and undertriage Evaluation of triage algorithms can be performed in numerous ways. The most definitive being differences in mortality. The aim of triage is correct resource allocation and the best evaluation should focus on the patient receiving ade-quate resources in a timely manner. There are however several pitfalls in this, the most obvious that the full extent of injuries is unknown when triage is performed. One way to evaluate triage is to study resource allocation to those patients in need of an immediate surgical procedure at primary survey. The current standard procedures in evaluating over- and undertriage is based on evaluating proportions of patients in different aspects. Patients are dichoto-mized depending on their injury severity score with a cut off at a score of 15 and labeled “not severely injured” or “severely injured”. This variable in then cross-tabulated to whether or not the patient initiated a full trauma team acti-vation (TTA). The two methods used in our studies are presented below. The Matrix method The gold standard in triage evaluation presented in figure 7. The overtriage is calculated by the proportion of patients not seriously injured (ISS<15) initiat-ing a full TTA. The undertriage is calculated by the proportion of severely injured patients (ISS>15) not initiating a full TTA.

Figure 7. The Matrix method for calculating over- and undertriage. ISS=Injury Se-verity Score, TTA=Trauma Team Activation.

Other methods for assessment of triage The Matrix method has an inherent error: If one reduces initiation of limited TTA, the denominator in the Matrix method undertriage calculation is reduced resulting in an increased undertriage proportion even if the actual number of severely injured patients not initiating a full TTA is unaffected or even re-duced. The increase of undertriage suggest insufficient means to triage pa-tients correctly and is a medical risk. But if the increase is based on our in-creasing ability to correctly divert uninjured patients away from the trauma bay the increase in undertriage is false. This has been observed at several in-stitutions world-wide, and an alternative method for calculating undertriage was recently commented on by Peng, et. al55.

Instead of comparing the proportion of severely injured patients who did not initiate a full TTA with all patients who did not initiate a full TTA like the Matrix method, the alternate method compares the proportion of severely in-jured patients who did not initiate a full TTA with all severely injured patients. This results in a dichotomization of the severely injured where it is preferable to have the larger proportion initiate a full TTA, but the proportion is com-pletely unaffected by a decrease or increase in limited TTA. This model is illustrated in figure 8.

Figure 8. The alternate method for calculating undertriage. ISS=Injury Severity Score, TTA=Trauma Team Activation.

National consensus based trauma team activation criteria In 2014 the sponsor of the Swedish trauma registry (SweTrau), the Swedish trauma association, held a meeting where the inclusion- and exclusion criteria for the registry was discussed. It was decided that the inclusion criteria would be changed from only including patients with NISS>15 to also include all pa-tients initiating a TTA. This change would not only increase the number of registered patients by a factor of ten, but also exploit a weakness in the regis-try: Would we compare the same patients if there was no national TTA crite-ria?

At first it was argued that we would be able to study registered trauma pa-tients regardless of the differences in inclusion due to different sets of TTA criteria. With increasing evidence to support exclusion of MVC as stand-alone criteria to initiate limited TTA, however, a presentation of current evidence for every single TTA criteria and its validity was held at the Swedish Trauma Network meeting in Stockholm 2015. At this meeting, financial and adminis-trative support was offered from a public Swedish insurance company (LÖF) to form an expert panel with the aim to present consensus-based TTA criteria.

The new national TTA criteria were presented December 1st 2016, and step-wise implemented in Sweden between December 1st 2016 and December 31st 2017. At present date, the criteria are to the best of our knowledge used at all Swedish hospitals dealing with trauma patients.

The implementation of the national consensus-based TTA criteria war-ranted a prospective clinical trial in order to test the accuracy, safety and va-lidity of the new TTA criteria. In order to do so, the TRAUMALERT-study was designed as a prospective stepped wedge cohort study of the new criteria

in the Uppsala-Örebro region including five hospitals serving 1.2 million in-habitants.

We hypothesized that the new TTA criteria would decrease limited trauma team activation by 50% with sustained levels of over- and undertriage.

Aims

The overall aim of this project was to evaluate the current practices in trauma patient assessment and triage in a Nordic context, as well as to identify possi-bilities for further improvement in these areas. The specific aims were:

I To assess the use of WBCT in a modern trauma cohort in Sweden and

evaluate if risk stratification criteria can be used for deciding need of im-aging in patients subject to high-energy trauma.

II To identify Nordic trauma centers WBCT imaging protocols, radiation

dose, and integration in trauma care, and to inquire about the need for common Nordic guidelines.

III To investigate if current trauma team activation criteria result in accepta-

ble under- and overtriage according to the Matrix method, and to estimate compliance to alert guidelines.

IV To evaluate the safety and efficacy of the new national trauma team acti-

vation criteria in Sweden.

Patients and Methods

Paper I This study assesses the use of WBCT in trauma in a retrospective two-center cohort study. All trauma patients presenting to two hospitals (a university hos-pital (July-December 2008), and a rural county hospital (January 2009-De-cember 2010) were included in this study. The patients were identified from the manual trauma register kept in the ED of the two hospitals during this time-period.

Patients were retrospectively divided into 3 groups based on risk of injury on first clinical evaluation. The risk stratification between high and interme-diate risk was based on the ACS-CoT guidelines for full and limited trauma team alerts:

1. High risk – Patients with signs of compromise to vital functions or predefined injury types, Figure 9. 2. Intermediate risk – Patients without signs of compromise to vital functions or predefined injury types, but with clinical findings sug-gesting at least one moderate injury (AIS ≥ 2), or intoxication. 3. Low risk – Patients with clinical findings limited to minor injuries (AIS ≤ 1) and no intoxication.

Figure 9. TTA criteria and risk group classification.

The included patients medical records were reviewed and information ex-tracted regarding patient age at admission, gender, mechanism of injury, find-ings at clinical examination, use of radiological imaging (WBCT and/ or oth-ers), findings at radiological imaging, changes in radiological reports (prelim-

inary vs final report), accidental findings, blood alcohol level, operations, in-tensive care, admission and follow-up. All patient records were reviewed for follow-up visits from the time of initial observation through December 2013 (a minimum of 36 months follow-up period).

Injury severity was graded using the Abbreviated Injury Score (AIS-2005 rev 08) and the AIS was used to calculate the Injury Severity Score (ISS)49. Patients with an ISS above 15 are considered as severely injured patients.

The three groups were assessed with regards to patient age and sex, mech-anism of injury, the use of WBCT, radiological findings, ISS and admission to surgical ward or intensive care unit (ICU) and mortality. Subgroup analyses were performed based on mechanism of injury, admitting hospital and on pa-tients examined with WBCT.

Paper II This study surveys the use of WBCT in trauma at Nordic trauma centers. A survey was sent to 95 Nordic hospitals and the radiologist in charge of emer-gency radiology or CT was asked to complete the questionnaire. The selection of hospitals was based on web-search, and hospitals with emergencies depart-ments where name and address to trauma radiologist or head of radiology de-partment could be found: Sweden (n=54), Denmark (n=21), Norway (n=5), and Iceland (n=2). A board member with personal knowledge of whom to contact in Finland selected 13 hospitals in Finland to include. The survey was also sent to 5 major trauma centers in the USA, two in the Netherlands, one in Belgium, one in Italy, and one in England. The questionnaire comprised 23 multiple choice and free text response questions. The questionnaire is found in the appendix of this thesis. Reminders were sent two times to the partici-pants, and they were also offered to have the questionnaire sent by regular mail, in order to ensure maximum response frequency.

Paper III This study assesses triage in a retrospective single center cohort. All trauma patients at a tertiary referral trauma center during 2012 were identified, and all primary trauma patients were included in the study.

Medical records were retrieved and 32 parameters were recorded including: age, gender, date of admission, MOI, trauma team activation, findings at phys-ical examination, radiological examinations and results, blood-alcohol level, NISS, admission and level of care, surgeries and diagnoses according to ICD-10.

The injury severity was calculated using the AIS-2005 rev 08 and this was used to calculate the ISS and NISS53. Over- and undertriage was calculated using the Matrix method 44.

At the study center, triage was performed by a senior nurse in the ED when contacted by the pre-hospital personnel or by a senior anesthesiologist in the medical helicopter service. Triage-criteria are shown in Figure 9.

Within the current study, compliance to current trauma alert criteria for full-, limited-, and no trauma team was calculated by studying the pre-hospital reports and re-triage the patients according to triage-criteria.

Triage was assessed with regards to age, sex, blood-alcohol level, NISS, MOI, compliance to alert-criteria, over- and undertriage and admission to sur-gical ward or ICU. Subgroup analyses were performed on over- and undertri-age and compliance to alert criteria based on MOI. Paper IV This study assesses the safety and efficacy of new national trauma team acti-vation criteria in a prospective step-wedged population-based cohort of trauma patients. All trauma patients registered in SweTrau at 5 hospitals in the Uppsala-Örebro region were included in this study. Four hospitals included patients 6 months prior to and after the introduction of the new TTA criteria. One hospital included patients 4.5 months prior to and after the introduction of the new criteria.

Patients were prospectively included upon initiating a TTA and registered in SweTrau. After collection of baseline data, the new TTA criteria was intro-duced and patients were included at an equal time before and after the inter-vention. Data regarding intervention group, age, gender, type of trauma team activation, mechanism of injury, injury severity according to NISS/ISS, Glas-gow Coma Score, pre-injury ASA and mortality was recorded and assessed for over- and undertriage with the Matrix method and the proportion of se-verely injured patients (ISS>15) not initiating a full TTA compared to all se-verely injured patients.

Risk-factors for undertriage were assessed with binary logistic regression analyses and a sensitivity analysis was performed on one hospital with a pre-hospital TTA routine prior to the implementation of the new TTA criteria.

Statistics Data were assessed for normality with histograms. Categorical data were re-ported as ratios with 95% confidence intervals (CI), and were assessed with chi-square when appropriate. Normally distributed continuous data were re-

ported as means with standard deviation (SD), and were compared with Stu-dent’s t-test. Non-normally distributed data were reported as medians with in-terquartile range (IQR) and compared with Mann-Whitney-U test. Predictors for undertriage were assessed in a multivariable binary logistic regression analysis. A p-value of <0.05 was regarded as significant. Statistical analyses were performed with IBM SPSS Statistics version 22-25 (IBM Corp, Armonk, New York, USA) and Microsoft Excel 2013 (Microsoft, Redmond, Washing-ton, USA).

Ethical considerations Paper I and III are based on retrospective data from a local trauma-registry, anonymous data collected at a county hospital for evaluation purposes and data collected at a university hospital for quality improvements. An applica-tion was sent to the local ethics committee with a request to use collected anonymized data for research. The committee waived the need for ethical ap-proval, regarding previously collected data, but did not have any objections for the use of the data in research. The committee approved the acquiring of future data without informed consent, for validation purposes. (Dnr 2014–250).

In Paper IV the optimal methodology to study this intervention without bias would have been a randomized controlled study, where patients would have been triaged with one of the two criteria based on randomization. Although we initially aimed for such a study design, it was not accepted by the ethical review board (Dnr 2016-202). They required informed consent prior to ran-domization from all patients, which we regarded as impossible to achieve. The study design was then changed to a prospective stepped wedge cohort design with data collection in the Swedish trauma registry. The ethical review board approved the study (Dnr 2017-405).

Figure 10. Previous trauma alert criteria used in paper I, III and IV based on ACS-CoT Orange book. Mechanisms of injury (above) initiate limited trauma team, de-ranged physiology and type specific injuries initiate a full trauma team.

Datum:...............................................

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Figure 11. The new national consensus-based TTA criteria evaluated in paper IV.

Results

Paper I A total of 523 patients were included. Eight patients were excluded; 3 due to de-activation of trauma alert; 5 patients could not be identified retrospectively. Only 1.1% of all patients were subject to penetrating trauma. Patient charac-teristics are shown in table 2 and the ISS score of the different risk groups is presented in figure 12. This box-plot visualizes the distributions of injuries and how few patients that were seriously injured. The mechanisms of injury, and their distribution in the groups are shown in table 3.

Table 2. Patient characteristics according to risk groups

Low risk group (n=139)

Intermediate risk group (n=322)

High risk group (n=62)

P-value

Age, mean, years (SD) 32.52 (21.35) 37.66 (20.24) 38.49 (21.13) 0.035 Male gender % (n): 61.2 (85) 64.3 (207) 77.4 (48) 0.075 Mechanism of injury % (n) <0.001 Unprotected traffic victim (motorcy-cle, bike, pedestrian) 20.9 (29) 34.2 (110) 24.2 (15) Protected traffic victim 62.6 (87) 36.3 (117) 40.3 (25) Fall<3m 10.8 (15) 13.4 (43) 3.3 (2) Fall>3m 2.9 (4) 7.8 (25) 17.8 (11) Other (crush, blunt, SW) 2.9 (4) 8.4 (27) 14.5 (9) Examined with WBCT % (n) 32.4 (45) 60.2 (194) 82.3 (51) <0.001 Injury on WBCT % (n) 0 (0) 44.8 (87) 74.5 (38) <0.001 Specific radiological exams % (n) 46.8 (65) 58.4 (188) 43.5 (27) 0.016 Injury Severity Score, mean (SD) 0.84 (1.57) 4.42 (6.30) 16.48 (18.14) <0.001 S-ethanol in mmol/l in intoxicated pa-tients, mean (SD) - 43.53 (23.54) 38.99 (15.80) 0.53 Intoxication on admission % (n) 0 (0) 7.8 (23) 25.0 (14) <0.001 Admission to intensive care unit % (n) 20.1 (28) 33.5 (108) 77.4 (48) <0.001 WBCT = whole body computed tomography

Figure 12. Boxplot of ISS according to risk group after subdivision into the studied groups.

Table 3. Patient characteristics according to mechanism of injury. After subdivision into the studied groups

Unprotected traffic victim

Protected traffic victim Fall <3m Fall >3m

Other (crush, blunt, SW) P-value

(n=154) (n=229) (n=60) (n=40) (n=40) Age, mean, years (SD) 33.6 (20.6) 35.0 (19.2) 44.5 (25.8) 43.3 (19.2) 36.1 (19.5) 0.002 Male gender % (n): 64.3 (99) 57.5 (132) 63.3 (38) 95.0 (38) 82.5 (33) <0.001 Examined with whole body CT % (n)

60.4 (93) 51.5 (118) 50.0 (30) 72.5 (29) 50.0 (20) 0.065

Injury on whole body CT % (n) 47.3 (44) 28.8 (34) 50.0 (15) 72.4 (21) 60.0 (12) <0.001 Specific radiological exams % (n) 61.7 (95) 46.3 (106) 56.4 (34) 62.5 (25) 52.5 (21) 0.033 Injury Severity Score, mean (SD) 5.3 (8.5) 3.5 (9.6) 5.2 (10.7) 8.0 (6.7) 7.7 (9.2) 0.009 Intoxication on ad-mission % (n) 8.6 (12) 4.8 (10) 7.1 (4) 16.2 (6) 17.6 (6) 0.031

Admission to inten-sive care unit % (n) 36.4 (56) 30.1 (69) 41.7 (25) 42.5 (17) 42.5 (17) 0.230

Almost half of all patients (229/523) were exposed to MVC and they had a mean ISS of 3.5 (9.6 SD) and 163 patients (71.1 %) had no significant injuries (ISS ≤ 1). Forty fall injuries from >3 m with a mean ISS of 8.0 (6.7 SD) were identified, and 9 (22.5 %) had no significant injuries (ISS ≤ 1).

There was no difference in rate of injury findings between the hospitals. More patients were admitted for observation or treatment at the county hospi-tal, with a large discrepancy in intensive care admissions (58 % county hospi-tal vs 14.3 % university hospital, p < 0.001).

Of the total of 523 patients, only 47 patients (9.0 %) did not go through any radiological exams and WBCT was performed in 290 patients (55.4 %), and showed traumatic findings in 125 patients (43.1 % of those examined with WBCT).

Patients examined with WBCT in all risk groups, tabulated in table 4, had no difference in age or sex, but there was a trend towards younger patients in the low risk group (p = 0.099). Overall, mean ISS was higher in patients ex-amined with WBCT 6.3 (10.7 SD) compared to patients not examined with WBCT 3.1 (6.4 SD). In the low risk group, there was no difference in ISS between patients examined with WBCT 1.2 (1.7 SD) and those who were not 0.8 (1.8 SD). No injuries were found on any of the WBCT performed in the low risk group, and at follow-up of 36 months or more, there was no finding of missed injuries in this group.

Table 4. Patient characteristics in patients examined with WBCT. Low risk group

(n=45) Intermediate risk group (n=194)

High risk group (n=51)

P-value

Age – mean, years (SD) 32.7 (19.6) 39.4 (19.9) 36.1 (19.4) 0.099

Male gender % (n): 66.7% (30) 70.6% (137) 76.5% (39) 0.560

Injury Severity Score, mean (SD) 0.96 (1.02) 4.86 (7.17) 16.71 (17.72) <0.001

Injury on whole body CT % (n) 0% (0) 44.8% (87) 74.5% (38) <0.001

Paper II

Response rate The response rates range between 92.3% for Finland and 23.8% for Denmark. The Nordic hospitals had a response rate of 60.2% (56/93), and the non-Nordic countries had a response rate of 80% (8/10).

WBCT official guidelines An alert policy for trauma patients that can be set off either from the ED or

the local ambulance service to optimize the staffing in the resuscitation room was present in 52 (96.4%) of the 56 responding Nordic hospitals and in seven (87.5%) of the eight non-Nordic hospitals. Official guidelines for when it is indicated to perform a WBCT were present in 47 (83.9%) of the Nordic hos-pitals (table 5) and in six (75.0%) of the non-Nordic hospitals.

Table 5. Guidelines for indications to perform WBCT and distribution for different hospital categories in the Nordic countries. Official guidelines for WBCT Hospitals, n (%) University

hospital District hospital

Local hospital

Departmental guidelines 27 (48.2%) 9/16 13/29 5/11 Regional guidelines 16 (28.6%) 1/16 12/29 3/11 Both 4 (7.1%) 2/16 2/29 0 No 0 0 0 0 No guidelines, but use WBCT 8 (14.3%) 4/16 2/29 2/11 Don´t know 1 (1.8%) 0 0 1/11

Of all the hospitals that responded, 46 (71.9%) answered that they perform WBCT after the primary survey. Survey data when WBCT is performed in the Nordic and non-Nordic countries are presented in Figure 13.

Figure 13. When WBCT is performed

Criteria to perform WBCT The criteria used for deciding if WBCT should be performed varied between hospitals (table 6). The most common criterion used was mechanism of injury. Three hospitals responded that they only use this specific criterion.

Table 6. Criteria used for deciding if WBCT should be performed.

Criterion Nordic hospitals, n (%) Non-Nordic hos-pitals, n (%)

Total (%)

Mechanism of injury 52 (94.5%) 6 (75%) 58 (92.1%) Abnormal vital signs 49 (89.1%) 7 (87.5%) 56 (88.9%) Anatomical site of injury 37 (67.3%) 5 (62.5%) 42 (66.7%) Presence of multiple injuries 46 (83.6%) 7 (87.5%) 53 (84.1%) Other 7 (12.7%) 3 (37.5%) 10 (15.9%)

Protocols for WBCT All hospitals answered that they use intravenous contrast routinely with a standardized volume intra-venous contrast in 7/8 (87.5%) of the non-Nordic trauma centers. In the Nordic hospitals 30 of 55 (54.5%) use a standardized dose and 25 (45.5%) personalize the dose depending on age, weight, gender, and renal function. table 7 shows the different regimes on how to visualize and use contrast medium in the WBCT. Table 7. How different body parts are visualized in Nordic hospitals (multiple choices allowed)

Body part Without contrast

Arterial phase

Venous phase

Combined arte-rial and venous phase

Excretory phase

Head 54 (98.2%) 1 (1.8%) 0 0 n/a Neck 42 (76.4%)* 7 (12.7%) 3 (5.5%) 3 (5.5%)** n/a Thorax 0 19 (34.5%) 26 (47.3%) 10 (18.2%)*** n/a Upper abdomen 0 9 (16.4%) 28 (50.9%) 15 (27.3%)*** 9 (16.4%)**** Lower abdomen (in-cluding pelvis)

0 6 (10.9%) 33 (60.0%) 12 (21.8%)*** 9 (16.4%)****

Lower extremity***** 0 0 1 (1.8%) 1 (1.8%) * Eight (14.5%) of the hospitals added that they perform neck scanning in arterial phase (CT angiography) if there is any sign of cervical injury in the first scan. ** Two of the hospitals use a split bolus technique. *** Six of the hospitals that combine arterial and venous phase commented that they use a split bolus technique. **** Seven of the hospitals that scan in excretory phase do this if there is a suspected renal collecting system injury. ***** Fifty-three (96.4%) do not include lower extremities routinely, but perform scans if there are suspected injuries.

Location of CT scanner The CT scanner was located inside or adjacent to the ED in 33 (60.0%) of the responding Nordic hospitals. Adjacent was defined as on the same floor and within 50 m from the ED. All non-Nordic trauma centers had a CT scanner located near the ED, two commented that the scanner is located inside the trauma room.

Radiation The average radiation dose to the patient during WBCT defined as the average Dose Length Product (DLP) (milligray [mGy] x cm) was reported by 37 (60%) of responding hospitals and four (50%) of the responding trauma centers. This is presented in Table 8.

Table 8. Radiation dose (DLP; mGy x cm) from WBCT in Nordic hospitals and in non-Nordic trauma centers

Hospitals (n) Maximum Minimum Mean SD Nordic 33 3600 900 1838 535 Non-Nordic 4 2750 1700 2200 505

Need for national/international guidelines In the last part of the survey responders were asked their view of the need for common guidelines concerning WBCT and if their radiology department would be interested in adopting new guidelines in the future. Some 89.1% agree regarding the need for national/international guidelines and 78.2% would be interested in adopting new guidelines in the future.

Paper III Out of a total of 1461 trauma patients, 37 were excluded due to various reasons (lack of examination prior to discharge (14), secondary trauma patients (8), not being subject to trauma (6), double registration (2), dead on arrival (1), patients with blocked medical records (2) or with protected identity (4).

A total of 1424 patients were thus included in the study out of which 73 (5.1%) patients activated a full trauma team, 732 (51.4%) activated a limited trauma team and 619 (43.5%) did not trigger activation of a trauma team. Full trauma team was activated for all patients who received an ISS of 75 (fatal injuries) and patients with full TTA were evenly distributed with a mean ISS of 23.5 (21.1 SD).

A limited trauma team was activated 732 times, and the mean ISS was 3.5 (5.3 SD). The main findings are in the over- and undertriage according to the Matrix method in table 9. Fall injuries >3m have a tendency to be undertri-aged. MVCs have a tendency to be overtriaged and the undertriage is well below acceptable limits of 5%.

Table 9. Over- and undertriage with the Matrix method according to MOI. Green color represents over- and undertriage at acceptable levels.

Mechanism of injury Undertriage 95% CI Overtriage 95% CI

(%) (%)

Motor vehicle crashes 0.4 0.1 - 0.9 47.1 27.8 - 77.0

Motorcycle crashes 5.0 1.4 - 12.3 0.0 0.0 - 52.2

Bicycle crashes 3.8 1.3 - 8.7 0.0 0.0 - 45.9

Horse accidents 4.9 1.3 - 12.0 100.0 - - -

Pedestrians hit 5.9 0.1 - 28.7 20.0 0.5 - 71.6

Fall injuries <3m in height 5.8 3.3 - 9.4 50.0 1.3 - 98.7

Fall injuries >3m in height 11.6 3.9 - 25.1 27.3 6.0 - 61.0

Other injuries 4.7 2.1 - 9.1 38.5 20.2 - 59.4

All injuries 2.7 1.9 - 3.8 32.9 22.3 - 44.9

The compliance to full trauma team alert criteria was 80% (95%CI 68-88%). For activating limited trauma team, it was 54% (95%CI 51-58%). There were also differences between various MOI displayed in table 10.

Table 10. Compliance to alert criteria. Yellow represents suboptimal compliance (<60%)

Correct level of alert 95% CI

Full trauma team activation 0.80 0.68 - 0.88

Limited trauma team activation 0.54 0.51 - 0.58

No trauma team activation 0.79 0.76 - 0.82

Motor vehicle crashes 0.70 0.66 - 0.74

Motorcycle crashes 0.72 0.61 - 0.81

Bicycle crashes 0.69 0.61 - 0.77

Horse accidents 0.41 0.30 - 0.52

Pedestrians hit 0.73 0.50 - 0.89

Fall injuries <3m in height 0.59 0.52 - 0.65

Fall injuries >3m in height 0.74 0.60 - 0.85

All injuries 0.66 0.64 - 0.69

Immobilization on a long spine board or with Kendrick Extrication Device (KED) was an independent risk factor for mistriage with an odds-ratio of 1.75 (95% CI 1.41 – 2.17). See table 11 for details. Patients brought in by anesthe-siologist in helicopter emergency service, or patients who only received a

semi-rigid neck collar for immobilization did not statistically differ in odds-ratio regarding mistriage.

Table 11. Odds-ratio for mistriage*

Paper IV During the study period, 1948 trauma patients were registered in SweTrau at the participating centres, 66 (3.4%) of which were excluded. The numbers of patients initiating full TTA, limited TTA and no TTA before and after change of trauma criteria are presented in the flow chart, figure 14.

Figure 14. Flowchart of patients included in the study

The demographics of included patients showed differences in the proportion of male patients activating a limited trauma team, a difference in penetrating trauma and in ISS of limited TTA patients. There was no difference in mor-tality, table 12.

Risk factor Odds-Ratio 95% CI P-value Equestrian accidents 3.05 1.94 - 4.80 <0.001 Low fall injuries (<3m in height) 1.51 1.14 - 1.99 0.004 Blood alcohol >15mmol/l 2.17 1.49 - 3.13 <0.001 Patient immobilized on long spine board/KED 1.75 1.41 - 2.17 <0.001 *Only risk factors with significant Odds-Ratio are included in this table for full table, please see paper III

Table 12. Study population demographics Former criteria

(n=1187) New criteria

(n=695) p-value

Age - median, years (IQR): 36 (21-60) 40 (22-61) 0.173 Full trauma team activation 40.5 (23-63) 43 (22-62) 0.726 Limited or no trauma team activation 36 (21-59) 40 (21-61) 0.129 Male gender % (n): 59.0 (704) 64.6 (450) 0.013 Penetrating trauma %(n): 2.4 (29) 7.8 (54) <0.001 Glasgow Coma Scale in Emergency Department, % (n):

Normal or minimal injury (GCS 15) 84.4 (1037) 82.3 (572) 0.003 Mild injury (GCS 13-14) 5.1 (60) 8.6 (60) 0.002 Moderate injury (GCS 9-12) 1.1 (13) 3.6 (25) <0.001 Severe injury (GCS 8 or below) 2.1 (25) 2.9 (20) 0.290 ASA-classification, median (IQR): 1 (1-2) 1 (1-2) 0.254 Injury Severity Score, median (IQR): Full trauma team activation 8 (1-16) 9 (1-16) 0.977 Limited or no trauma team activation 1 (0-4) 2 (1-8) <0.001 New Injury Severity Score, median (IQR): Full trauma team activation 9 (3-25) 9 (2-21) 0.848 Limited or no trauma team activation 2 (0-4) 3 (1-9) <0.001 30-day mortality % (n): Full trauma team activation 13.8 (20) 12.1 (17) 0.662 Limited or no trauma team activation 1.7 (18) 2.6 (14) 0.268 IQR=Interquartile range, ASA= American Society of Anesthesiologists Physical Status

Over- and undertriage Overtriage was 71.3% (107/150 patients) with the former TTA criteria and 72.2% (104/144 patients) with the new TTA criteria, p=0.866. Undertriage calculated with the Matrix method was 4.8% (50/1037) with former criteria and 7.1% (39/551) with new criteria, p=0.063. 53.8% (50/93) of severely injured patients (ISS>15) did not initiate full-TTA with former, vs 49.4% (39/79) with new criteria, p=0.565.

Subgroup analysis of undertriage Undertriaged patients according to injury mechanism are presented in figure 15. Road traffic accidents constitute 55.3% (656/1187) of all patients with former criteria and 52.9% (368/695) with new criteria. Ten patients subject to road traffic accidents were undertriaged with former and nine with new criteria, p=0.204. Patients subject to low fall injury constituted 13.8% of the

trauma patients (164/1187) with former and 12.2% (85/695) with new crite-ria, p=0.327. Eighteen of these patients were undertriaged with both former and new criteria p=0.051.

Figure 15. Proportion of undertriaged patients based on mechanism of injury. Error bars indicate 95% confidence interval.

Risk factors for undertriage Binary logistic regression analyses of risk factors for undertriage indicate a higher risk for undertriage in patients ≥60 years of age, table 13. There was a trend for increased risk for undertriage in patients with fall injury.

Table 13. Odds-ratio of risk factors for undertriage

Odds-ratio 95% CI p-value

Mechanism of injury Motor vehicle accident 0.431 0.15 - 1.27 0.126 Motorcycle accident 0.743 0.19 - 2.84 0.664 Bicycle accident 0.546 0.13 - 2.35 0.416 Pedestrian hit 0.563 0.06 - 4.99 0.606 Gunshot wound 0.000 0.00 - 1.000 Stab wound 0.000 0.00 - 1.000 Low fall injury 2.704 1.00 - 7.35 0.051 High fall injury 1.681 0.63 - 4.47 0.298 Age ≥60 years 2.886 1.74 - 4.79 <0.001 ASA-classification≥3 0.935 0.53 - 1.66 0.818ASA= American Society of Anesthesiologists Physical Status

Reduction in TTA – who was affected? The reduction in limited TTA with the new criteria was from 988 patients to 531 patients (46% reduction). In order to evaluate this reduction, it is im-portant to know which patients did not initiate a TTA. The overall rate of overtriage was the same with former and new TTA criteria, and there was no significant difference in undertriage with former and new criteria. By plotting a bar chart with ISS groups of 0-2 and 3-75, the results are visualized in figure 16. 88% of the reduction occurred in patients with ISS <3.

Figure 16. Number of patients grouped by Injury Severity Score and paneled by for-mer and new criteria.

General discussion

Excellent trauma care is not only about performing the right measures in each specific patient situation, but also about carefully planning and managing re-sources, both in their utilization and the time frame in which they are used. When a patient is subject to traumatic injuries the clock starts ticking and if the patient is actively bleeding the time until the bleeding is stopped affects outcome. To meet this challenge, it is imperative to have the right resources present at the right time. This is where the inclusive trauma system comes into play. You do not have time to set up the plan based on the known facts of every incidence, but instead you have to have a sturdy plan on how trauma is managed in your region that starts with preventive measures and end after re-habilitation of the trauma patient.

Whole body computed tomography The liberal use of WBCT in patients subject to trauma is a key adjunct in de-livering the best trauma care. WBCT is crucial in finding occult injuries when distracting injuries are present, or when the patient is influenced by alcohol or other drugs.

Disadvantages in the liberal use of WBCT include exposition to ionizing radiation. Population based estimates suggest that approximately 0.1% of the current cancer incidence is due to medical radiation exposure.56 This provides medical staff with a dilemma: Should one use WBCT, and thus expose the patient to radiation averaging about 2000 mGy x cm? The advantages are im-minent as the WBCT will help doctors find and map patient injuries, while the disadvantages are risks calculated by data extrapolation from massive radia-tion exposures57, and with the uncertainties associated with this method. The benefit from WBCT exceeds the risks if there is a substantial risk that the patient is seriously injured. At the same time, obviously CT scanning of the whole population without an indication has risks that exceeds the benefits. According to the Swedish Radiation Safety Authority regulatory code in med-ical practice, medical practitioners are obligated to keep the radiation dose as low as reasonably achievable (ALARA principle), but at the same time ensur-ing that the needed diagnostic information is obtained58.

In paper I, we concluded that if the patient did not have clinical signs of serious injury, was conscious and alert and with no signs of alcohol- or drug

intoxication, there were no serious injuries missed regardless of whether a WBCT scan was performed or not. Still, the liberal use of WBCT lead to some incidental findings requiring further investigations and in a few cases even contributed to finding cancer present without symptoms. At the same time, findings in WBCT also lead to adverse effects in several patients and one pa-tient was treated for a non-existing cervical fracture with 6 weeks of c-spine immobilization.

A WBCT without injury findings can be considered an unnecessary exam-ination, but it still gives a lot of information. The results can be used to dis-charge a patient instead of admitting, and it can be reassuring to both patient and doctor.

One cannot discuss radiation without considering the age of the patients because radiation induced damage to cell proliferation is an accumulative pro-cess. The mean age of all trauma alert patients in paper I and III (n=1328) is 39.5 years and with the current life expectancy in Sweden of 81.8 years, they have an average life expectancy of more than 42 years.

Triage Triage is a resource allocation system where fine resources are rationed based on previous experience and science. Every region of the world has their pan-orama of trauma, and the triage system is influenced by this, but not always in an optimal way. The American college of surgeons has developed a triage algorithm well suited for the American panorama of trauma at the time the algorithm was developed. But is this algorithm suitable for other regions with different prevalence of type injuries? Are mechanisms of injury constant over time? The answer to both questions is both yes and no, since the triage algo-rithms are based on physiology, with boundaries that are constant regardless of the MOI, type specific injuries that have been proven to accurately predict serious injury, and MOI criteria – incidents we consider dangerous based on previous experience. Derangements in physiology are with few exemptions a proof of that the trauma patient has sustained injuries and it is good resource management to gather the full trauma team for the initial assessment48. How-ever, at an early stage, the physiology of the patient can be normal even with an ongoing intraabdominal bleeding. The injuries in themselves can be seri-ous, but enough time has not yet passed for the patient to be physiologically deranged.

The same is true for type specific injuries as they accurately predict the seriously injured patient. If there are anatomic injuries such as multiple frac-tures, or a truncal gunshot wound, present already at the scene of injury, the patient is at high risk of serious injuries and will benefit from a multidiscipli-nary approach in the initial assessment.59, 60

Deranged physiology in combination with type specific injuries have a high probability for the patient to be seriously injured47, 60. This is also true in a military environment where admission physiology criteria predict both mor-tality and resource utilization61.

Figure 17. Triage decision scheme utilized for an incoming trauma patient

Mechanisms of injury are not constant over time. In the early 20th century, accidents with horse and carriage were common, and working in the fields with animals and primitive machinery caused injuries uncommon today. The recurring eruption of war has introduced mechanisms of falling debris in shelling, direct injuries due to explosions and penetrating trauma from all the devices developed to assist in man’s inhumanity to man. The general suffering during war also contribute by the ever-present fatigue of people where their basic needs for sleep and food are not met. In addition, the sanitary conditions in war will inevitably lead to contaminations of injuries and the need for al-ternate treatment compared to peacetime conditions62. The luxury of allocat-ing resources to patients based solely on MOI has not been an option under strenuous circ*mstances where the needs far exceed available resources.

Motor vehicle crashes are the most common mechanism of injury globally today. The number of deaths by this MOI is still increasing in the developing world, while there is a decrease in MVC deaths in the western world.2 The speed at which cars travel does not differ much with the income status of the country, if anything, average speeds tend to be higher in countries with a de-creasing death toll. The technical advances in modern cars in combination with the mandatory use of safety equipment are key factors in reducing inju-ries and death in traffic.2 In combination with primary preventive measures such as separation of opposing lanes and roundabouts the sole mechanism of

injury presented by MVCs has a decreasing predictive value for serious injury in the most developed countries.63

Over the last decades the population in the western world are getting older, and the panorama of trauma is changing with a decrease in MVC and an in-crease in fall injuries64.

It has become apparent that the trauma alerts criterion on mechanism of injury needed to be revised in the Nordic countries. As we showed in paper III, the risk for serious injury in a patient without deranged physiology or type specific injures following a MVC is only 0.4% in our region, and the alloca-tion of resources solely based on MOI can be questioned.

A change in triage algorithms for MOI could decrease resource utilization by 50% in less activation of limited trauma teams65, but this can be questioned in a two tier alert system, as the resources needed in treating a patient subject to high energy trauma is essentially the same if it is initiated by a limited trauma alert or as a normal examination without an alert. The major difference is in timing; since the alert patient is examined immediately, and the non-alert patient is examined when it is appropriate given the needs of other patients at the ED.

When MOI triggers a limited trauma team it does not affect overtriage, cal-culated by the matrix method in a two-tier trauma alert system.

Studies on over- and undertriage are summarized in table 14. The focus of the table is on Nordic studies as these patients are the most similar to patients in our paper III and IV. The methods for calculating over- and undertriage varies in different studies, and in table 14, we have chosen to include studies where undertriage is calculated with the matrix method and/or as the propor-tion of severely injured patients who did not initiate a full TTA compared to all severely injured patients.

Table 14. Studies on triage criteria with over- and undertriage estimations First author, ref-erence Year N Country Death

(%) Overtriage (%)

Undertriage matrix (%)

Undertriage 1-PPV (%)

Davis JW66 2017 7,031 USA 5.5 45 24

Dehli T67 2016 324 Norway 5.6 74 28

Granström A68 2011 1,408 Sweden 5.1 74 7

Granström A68 2013 1,466 Sweden 3.7 52 10

van Laarhoven JJ69 2014 1,607 Netherlands n.a 40 11

Brown JB70 2011 1,086,704 USA 4.6 22 51

Rehn M71 2012 1812 Norway 5.2 65 30

Dehli T48 2011 441 Norway 6.6 71 32

Curtis K72 2010 5,233 Australia 69 8 42

Linder F 2018 1,424 Sweden 1.1 33 4

Linder F 2018 1,187 Sweden 3.2 71 5 54

Linder F 2018 695 Sweden 4.5 72 7 49

Undertriage can also be assessed by evaluating the proportion of immediate life-saving interventions performed on patients not triggering full TTA. This method is substantially different from methods using injury severity scoring algorithms and undertriage is usually below 2% in studies using this method46,

73. Some procedures such as resuscitative thoracotomy is easy to categorize, while other measures such as placement of a central line can be effectuated immediately or several hours later, or even omitted leaving a substantial ob-servational bias in the assessment of undertriage. Just because the intervention was performed does not guarantee it had to be done at that time or in that manner.

The formation of a Swedish expert-panel with participation from some 20 professional organizations involved in trauma care, with a mission to go through the literature regarding triage and evidence for every specific criterion used, was successful, even with limited or even contradictory evidence regard-ing which system is superior in trauma triage74. The presentation of the con-sensus-based TTA criteria was received with enthusiasm in Sweden, and the implementation was uneventful.

AIS-scoring and triage bias Paper I and III are both retrospective studies where AIS was used for scor-

ing injuries and subsequently to calculate ISS and NISS. The scoring was per-formed by the authors and this introduces a bias. The AIS 2005 rev 2008 was used and even though all cases with ISS>9 was thoroughly evaluated by two or more authors with medical professions, we had not attended an AIS classi-fication course prior to these studies. This was remediated before the start of the study reported in paper IV, where the scoring is of better quality, per-formed only by accredited personnel and with a specific program in the web-based entry-module for SweTrau. The scoring of difficult cases at all includ-ing sites was also validated by re-scoring by accredited personnel from an-other including site.

The risk-group stratification in paper I is based partially on triage and in paper III triage decisions affect the rates of over- and undertriage. The triage was with few exceptions performed by a senior nurse in the ED, or by pre-hospital staff and the correctness in these decisions, made in a stressful envi-ronment, with limited information at hand, is difficult and prone to error. As we showed in paper III, the compliance to alert-criteria was only 54% regard-ing limited TTA introducing a bias. The previous studies listed in table 14, as well as other studies on over- and undertriage are prone to the same error and while the numbers reflect the actual outcome of triage, it is virtually impossi-ble to evaluate the TTA criteria with this questionable compliance and lack of information regarding the specific criteria initiating the alert.

Ethical considerations In order to follow up the change in trauma team activation criteria a ran-

domized controlled study would have been preferable. The alert criteria had recently been changed in Norway, based on clinical judgment and best prac-tice, but without a follow-up study.

Ethical considerations in a prospective triage study included the dilemma of informed consent. It cannot be considered ethical to ask the trauma patient to participate in a study during an accident, and the randomization must there-fore take place before the patient is informed and informed consent to inclu-sion in the study must be obtained at a later stage. This was denied by the ethical review board and an alternative approach was initiated where the study was performed within the routine clinical practice and a planned change of TTA criteria. The stepped wedge study design75 was chosen and proved to be an efficient method to prospectively study a clinical change in play.

Compliance to alert criteria Triage criteria, guidelines and protocols have been implemented for the rea-sons of safety, standardization and resource management. Protocol, and pro-tocol adherence in trauma triage has been identified as a future research pri-ority76, and in paper III we have tried to study compliance to alert criteria. Our studies show that compliance to set parameters is an important factor in evaluation of data. For instance, compliance to limited TTA criteria in paper III is only 54% (95%CI 51 – 58%). Conclusions drawn on the algorithm itself will be weak if the compliance is not sufficient. In this case, 46% of patients triaged to limited alert according to present criteria were not in the right triage group. 21 limited alert patients meet the criteria for full trauma alert. Some 193 limited trauma alert patients should not have activated any trauma alert. In paper III we re-triaged the patients based on the prehospital reports, and with the Matrix method, we concluded that the results on over- and undertri-age were still valid despite the lack of compliance to alert criteria in all groups. Patient demographics as well as ISS and NISS in our two-tier trauma alert system is well in line previously published data, in a Nordic, European and North American setting with some variations regarding prevalence of pene-trating trauma71, 77, 78.

The reasons for this lack of compliance to alert criteria may be found in the circ*mstances when the alert is initiated. First, if the telephone report to the triage nurse lacks sufficient data, the result could be an incorrect alert. Second, routines and guidelines for trauma alert activation may come in conflict with routines for management of the immobilized patient or routines to prevent emergency room overcrowding. In a study on compliance to inter-hospital transfer guidelines before and after initiation of a new protocol the overall

compliance was between 62-67%79. Studies on compliance to trauma alert cri-teria in a modern medical environment are scarce, but a recent study from the University of Minnesota and the University of Michigan including 51,792 pa-tients at 29 trauma centers in Michigan, USA during 2014-2016 showed com-pliance to full TTA ranging between 51-82%80. These results support our con-clusion in paper III regarding 80% as an acceptable level of compliance to full TTA.

If the patient is immobilized in transport or on admission, she requires con-stant surveillance until immobilizing measures have been terminated. In a situ-ation where the patient is subject to an MVC, and is immobilized but does not meet the criteria for orange trauma alert, it can be argued to initiate a limited alert anyway, because the patient will then receive an immediate evaluation upon arrival and immobilization can be terminated. If an alert is not initiated, the receiving nurse will be designated for this patient only until there is a doctor available for examination. There may be other patients with greater needs in the ED and the waiting time can sometimes be substantial. During this time, staff is prevented from dealing with other patients. An interesting approach in address-ing the problem with immobilization is the use of the Canadian c-spine rule by nurses to reduce unnecessary immobilization in the ED81. This would enable the ED nurse to discontinue with immobilization after the patient has been evalu-ated, thereby resolving the issue of constant surveillance of the immobilized patient and may affect compliance to alert criteria.

The survey presented in paper II also presses an issue of compliance. In the vast majority of hospitals included in the survey, ATLS is the base at which the delivery of trauma care is performed. ATLS clearly state that WBCT is an adjunct to the secondary survey. Still, 12.5% of Nordic countries and 10.9% of non-Nordic countries report that they perform WBCT before or as a part of the primary survey. If this is due to a local practice in conflict with the ATLS concept, or a misinterpretation on the responders’ part on how their own pro-tocol works, is unclear.

The seasonal distribution in trauma Trauma is not evenly distributed, but rather seasonal in prevalence. In paper IV this seasonal variance had to be accounted for in order not to over- or un-derestimate the results of the study. SweTrau was used to show the seasonal variation over the year and to link it with the stepped wedge inclusion periods. The expected results would have been a 10% increase in trauma prevalence without intervention. The seasonal distribution and inclusion intervals for pa-per IV is shown in figure 18. The variation in both number of trauma patients and type of trauma advocates a randomized trial instead of a stepped wedge cohort study, but as mentioned earlier the ethical review board and Swedish law prohibits a randomized clinical trial with a delayed informed consent. The

results in paper IV must be interpreted bearing this in mind. The number of motorcycle accidents for instance, is not evenly distributed among study groups.

Figure 18. The historic seasonal variance in TTA and the stepped wedge inclusion periods.

The Swedish Trauma Registry SweTrau registered some 20 800 patients between 2014-2016, and to date the total number of patients registered is >30 00082. The registration follows the Utstein template which enables studying over- and undertriage in a trauma cohort. One weakness in the current registration algorithm is that only level of trauma team activation is registered, not the specific grounds for initiating a trauma alert.

This limits the ability to evaluate the efficacy of every single specific cri-teria both in specificity and sensitivity. Information on mechanism of injury is present, which enabled our sub-group analysis of undertriage in paper IV, but it would be preferable if future registration contained the exact TTA crite-ria for future evaluation.

Until then, the Uppsala-Örebro region has agreed to include this infor-mation as a free variable starting 2018, to enable further evaluation of not only the whole package of TTA criteria but rather every specific criterion regarding specificity and sensitivity.

Prospective stepped wedge inclusion timeline(n=1882)

2500

2000

1500

1000

500

3000

20172016

Historic average registrationsper month (SweTrau 2014-2016)

Former trauma teamactivation criteria

New trauma teamactivation criteria

Västerås (n=571) 4•5 + 4•5 months

Uppsala (n=329) 6 + 6 months

Gävle (n=434) 6 + 6 months

Hudiksvall (n=338) 6 + 6 months

Karlstad (n=210) 6 + 6 months

Num

ber o

f pat

ient

Figure 19. The Swedish trauma registry website for registration and data extraction.

Conclusions

The current practices in trauma care regarding triage and use of WBCT in a Nordic context has been evaluated in this thesis. • WBCT rarely detects a significant injury in trauma patients who are men-

tally alert, not intoxicated nor shows signs of other than minor injuries when evaluated by a trauma-team.

• Protocols for WBCT in trauma is currently defined locally by most Nordic

trauma hospitals. • The scanning protocols differ significantly between centers but there is an

interest to endorse new national guidelines for WBCT. • The rate of undertriage in a Swedish cohort is in line with current recom-

mendations by the American College of Surgeons Committee on Trauma. • Further improvement of compliance to established TTA criteria may op-

timize resource allocation, with adequate levels of over- and undertriage. • The newly implemented Swedish TTA criteria are safe, with levels of

over- and undertriage remaining consistent after change of TTA criteria. • The number of limited TTA diminished significantly with the new crite-

ria, resulting in an increased efficiency in use of in-hospital resources, without compromising patient safety.

• Elderly patients subject to fall injury have a high risk for undertriage and

further evaluation of TTA criteria are motivated in order to decrease un-dertriage in this group of patients.

Future perspectives

Triage will remain a key component in resource allocation during a foreseea-ble future, and even with the successful implementation of national TTA cri-teria, work still needs to be done in order to achieve an evidence based inclu-sive trauma care system.

Use of WBCT in trauma The use of WBCT in the trauma cohort is influenced by standard operating procedures (SOP) in trauma care. The implementation of new consensus TTA criteria and guidelines limiting the use of spinal immobilization could poten-tially reduce the use of indiscriminate WBCT protocols and instead favor aimed investigations and thereby reducing radiation exposure. A retrospective single- or multicenter cohort study could further investigate the matter.

Evaluation of specific TTA criteria The evaluation of the new consensus TTA criteria was based on outcome for the whole package of criteria and to some extent in regards to specific mech-anisms of injury. The rates of over- and undertriage were not evaluated for every single criterion, because the information was not available in our data. A future study is in the planning process where information regarding every single criterion and its use would be gathered. The study could evaluate over- and undertriage of every single criterion, as well as the frequency at which a criterion is used. Several previous studies have concluded low fall injuries and extremes in age constitute challenges in terms of undertriage, and further stud-ies with specific aim on patients with low fall and high age may contribute to the understanding of how to identify patients at risk. The analysis of how cri-teria is used would enable further adapting the consensus TTA criteria and assist in decreasing over- and undertriage.

Validation of SweTrau The Swedish trauma registry, SweTrau, was used in paper IV, but it has not

yet been externally validated. A future study with interest to anyone basing research on SweTrau would be a thorough validation with an external valida-

tion of traffic-accident in SweTrau validated against The Swedish Traffic Ac-cident Data Acquisition (STRADA). Both registers use AIS for injury classi-fication. The Swedish intensive care registry (SIR) could also be used. Vali-dation against source-data could be done with re-registration and complete-ness and coverage should also be evaluated. The validation of SweTrau is im-portant in future studies based on the registry.

Using the TTA criteria for pre-hospital triage? Pre-hospital resource allocation has been addressed in the Norwegian

trauma system with harmonized criteria regarding where, when and how a trauma patient should be transported. The Swedish algorithms for prehospital care is based on local protocols and lack national guidelines. The use of the TTA guidelines as pre-hospital transport algorithm and resource management directions could be studied.

The use of spinal immobilization The reduction in spinal cord disruption during the 1970s and 1980s has

been interpreted as a result of the introduction of spinal immobilization, but in more recent studies it has been questioned83. A multi-center study of the new Swedish consensus based spinal immobilization guidelines with matched controls could add valuable knowledge and in conjunction with other studies serve as base for changed national immobilization guidelines. The use of pre-hospital immobilization has implications on use of TTA criteria and compli-ance to these guidelines. Revised guidelines regarding spinal immobilization could be studied, not only regarding the effect on spinal injury, but also on the effect on over- and undertriage and compliance to TTA criteria.

Sammanfattning på svenska (Summary in Swedish)

Trauma är den vanligaste dödsorsaken i Sverige för unga människor mellan 15–44 år och orsakar såväl stort lidande för den enskilde och anhöriga, som stora samhällskostnader. Traumavården har under de senaste årtiondena ge-nomgått stora förändringar och överlevnaden efter svåra olyckor har förbätt-rats, men det är en positiv utveckling som tar stora resurser i anspråk. Genom införande av traumalarm där många olika sorters läkare och sjuksköterskor aktiveras i det initiala omhändertagandet av traumapatienter på akutmottag-ningen har stora resurser bundits upp i omhändertagandet och det är därför viktigt att dessa resurser riktas till rätt patienter. Frikostig användning av rönt-genundersökningar för att kartlägga skador är även detta en del i modernt traumaomhändertagande.

I denna avhandling har vi specifikt tittat på utnyttjandet av helkropps skiktröntgen vid trauma samt resursallokering till traumapatienter kallat ”tri-age”.

Användning av helkropps skiktröntgen för patienter som varit med om stora olyckor utvecklades under tidigt 90-tal och har sedan dess blivit ett stan-dardförfarande vid traumaomhändertagande. En helkropps skiktröntgenun-dersökning tar cirka 20 minuter att genomföra och innebär att patienten un-dersöks utan och med kontrastmedel som injiceras i blodbanan. Undersök-ningen är mycket bra på att hitta skador orsakade av det våld patienten utsatts för, och kan även leda till upptäckt av tumörer och förändringar som ännu ej givit symptom. Samtidigt resulterar en helkroppsundersökning med skiktrönt-gen stora stråldoser till patienten och strålningens risker måste vägas mot undersökningens potentiella fördelar. Frågan om stråldoser är särskilt aktuell vid trauma då olyckor främst drabbar unga vuxna.

Triage vid trauma syftar till att larma rätt medicinska resurser i rätt tid för att bistå vid patientens omhändertagande. Det vanligaste systemet för triage vid trauma i Sverige är ett tvådelat system där begränsade resurser larmas till akutmottagningen vid olyckor med högenergetisk skademekanism och ett fullständigt traumateam larmas till akutmottagningen om patienten på skade-plats eller under intransport uppvisar tecken på sviktande vitala parametrar eller uppvisar en fördefinierad typskada såsom flera frakturer på långa rörben eller förlamning. Vissa svenska sjukhus har en gemensam larmnivå för alla traumafall. Triage är bra för att ransonera medicinska och tekniska resurser

till dem patienter med de största medicinska behoven, men man behöver kon-tinuerligt följa upp att resurserna inte överutnyttjas. Än viktigare är att följa upp så att svårt skadade patienter inte missas med dessa kriterier och dess till-lämpning.

2016 genomfördes en nationell evidensgenomgång av larmkriterier för tri-age på sjukhus, och en expertgrupp lanserade nationella konsensus-kriterier för traumalarm nivå 1 (fullständigt) och nivå 2 (begränsat) traumalarm. Dessa kriterier har eller kommer att införas i hela Sverige, och har i denna avhandling utvärderats med avseende på säkerhet och träffsäkerhet.

Delarbete I Patienter utsatta för högenergetiskt trauma som vid undersökning av

traumateamet är vakna, alerta, och endast uppvisar tecken till ringa ska-dor har ingen nytta av en helkropps skiktröntgenundersökning.

Helkropps skiktröntgenundersökning har tidigare genomförts närmast slentrianmässigt hos patienter där ett traumalarm aktiverats. Det innebar väl-digt många undersökningar samtidigt som fynden varit få och utgjorde anled-ning till varför denna studie initierades. Genom att analysera alla patienter som aktiverat ett nivå 1 eller nivå 2 traumalarm vid Akademiska sjukhuset andra halvan av 2008 samt alla patienter som aktiverat ett traumalarm vid Visby lasarett 2009–2010 kunde 531 patienter identifieras och 523 inkluderas i stu-dien. Trubbigt våld var den dominerande skademekanismen (98.9%) och pa-tienterna risk-stratifierades utifrån larmkriterier och fynd vid första undersök-ning på traumarummet till tre grupper. Hög risk (62 patienter) där den högsta larmnivån utlösts, intermediär risk (322 patienter) där högenergetisk skade-mekanism och tecken till skada eller otillräknelighet vid första undersökning förelåg, och låg risk (139 patienter) med högenergetisk skademekanism men där klinisk undersökning inte ingav misstanke om skada annat än små blessy-rer.

I lågriskgruppen genomfördes helkropps skiktröntgenundersökning på 32.1% av alla patienter, men ingen skada upptäcktes. I högriskgruppen ge-nomfördes helkropps skiktröntgenundersökning på 82.3% av alla patienter och 74.5% hade skador som påvisades med undersökningen. Medelålder för patienter i lågriskgruppen var 32.5 år.

Patienter utsatta för högenergetiskt våld som är vakna, alerta, och endast uppvisar tecken till ringa skador kan observeras och undersökas på nytt vid ett senare tillfälle istället för att genomgå helkropps skiktröntgenundersökning. Detta bör särskilt beaktas hos unga människor där långtidseffekter av jonise-rande strålning inte kan uteslu*tas.

Delarbete II Helkropps skiktröntgen är utformad efter lokala protokoll men det finns ett intresse för att utveckla nordiska riktlinjer för hur undersökningen skall genomföras.

Det finns i Norden ett flertal protokoll över hur en helkropps skiktröntgen-undersökning ska genomföras vid trauma med avseende på tjocklek på snitt, användning av intravenös kontrast och i vilka faser undersökningen sedan ge-nomförs. Varje undersökningsform har sina för- och nackdelar när det gäller att påvisa specifika skador, men de många alternativen påverkar tiden en undersökning tar, den stråldos patienten utsätts för, mängden intravenös kon-trast samt ger upphov till tolkningsproblem då bilder skickas mellan sjukhus.

Genom en enkät tillfrågades 95 sjukhus i norden samt 10 internationella traumacenter. Undersökningen bestod av 23 frågor och svarsfrekvensen var 62.1%. Det förelåg lokala riktlinjer för användningen av helkropps skiktrönt-gen vid trauma hos 83.9% av svarande sjukhus och 94.5% av de nordiska sjukhusen hade högenergetisk skademekanism som kriterium för undersök-ningen.

Datortomografen var placerad i direkt anslu*tning till akutmottagningen hos 60% av svarande sjukhus, och det förelåg stor variation kring hur undersök-ningen av olika kroppsregioner genomfördes och på vilket sätt intravenös kon-trast användes, men 89.1% av svarande ansåg att det vore bra med nordiska riktlinjer kring hur helkropps skiktröntgen vid trauma ska genomföras.

Stråldosen var i genomsnitt 1838 mGy x cm vid nordiska sjukhus och 2200 mGy x cm vid internationella traumacentra.

Delarbete III Bättre följsamhet till gällande larmkriterier skulle minska antalet larm med likvärdiga nivåer på över- och undertriage.

Kriterier för traumalarm bör återkommande utvärderas avseende dess träff-säkerhet att rikta resurser till svårt skadade patienter (övertriage) samt risken att missa allvarligt skadade patienter (undertriage). Träffsäkerheten i gällande larmkriterier är dock svår att utvärdera om följsamheten till kriterierna är låg då det blir en osäker koppling mellan resultaten på sjukhusnivå, och hur dessa resultat faktiskt förhåller sig till larmkriterierna.

Genom att undersöka hela traumakohorten vid Akademiska sjukhuset un-der 2012 och följsamheten till gällande traumalarmskriterier har larmsystemet utvärderats avseende träffsäkerhet, följsamhet till kriterier samt säkerhet. Matrixmetoden användes för beräkning av över- och undertriage.

Totalt identifierades 1461 patienter varav 1424 inkluderades i studien. 73 patienter aktiverade ett nivå 1 traumalarm, 732 aktiverade ett nivå 2 trauma-larm och 619 patienter aktiverade inget traumalarm. Övertriage var 32.9% och

undertriage 2.7%. En analys av följsamheten till larmkriterier visade att Nivå 1 larm hade en följsamhet till kriterier på 80%, nivå 2 larm en följsamhet på 54% och patienter som inte utlöst traumalarm hade en följsamhet på 79%. Följsamheten får därmed anses adekvat för nivå 1 larm samt för patienter som inte utlöst något traumalarm. Däremot är följsamheten till nivå 2 larm lägre vilket sammantaget givit upphov till 172 fler larm än vad kriterierna stipulerar.

Med en bättre följsamhet till larmkriterierna skulle övertriage vara 42.6% samtidigt som undertriage skulle vara 2.3% vilket statistiskt sett är oförändrat jämfört med nuvarande utfall.

Delarbete IV De nya nationella konsensuskriterierna för traumalarm har minskat an-talet nivå 2 larm med 46% med minskad resursåtgång på sjukhus som följd. Över- och undertriage är oförändrat jämfört med tidigare krite-rier.

I samband med förändrade inklusionskriterier för det svenska traumaregist-ret uppstod ett behov av nationella kriterier för traumalarm för att säkerställa likvärdig registrering. En expertgrupp med deltagare från 20 professionella organisationer involverade i traumavård utarbetade ett förslag på konsensus-baserade larmkriterier i god överenstämmelse med gällande evidens som an-togs vid nätverksmöte för trauma i Stockholm, december 2016. De nya krite-rierna infördes i etapper, men dessförinnan initierades denna prospektiva ko-hort-studie där de gamla kriterierna för traumalarm jämfördes med de nya.

En stickprovsanalys visade ett behov av minst 588 patienter per grupp för att kunna påvisa en skillnad i undertriage från 4–8%.

Fem sjukhus i Uppsala-Örebro regionen med ett primärt upptagsområde på 1 200 000 invånare ingick i studien och 1948 patienter identifierades varav 1882 patienter inkluderades. Det förelåg ingen skillnad i nivå 1 traumalarm före och efter införandet av nya larmkriterier, men nivå 2 larmen minskade med 46%. Det förelåg ingen skillnad i dödlighet och en analys kring vilka patienter som inte längre utlöste larm påvisade att 88% av dessa uppvisade en skadepoäng på 0–2 på en skala från 0–75 med svårare skador vid högre poäng.

Övertriage var 71.3 respektive 72.2% med de gamla och nya kriterierna och undertriage var 4.8 respektive 7.1%. Det förelåg ingen statistiskt påvisad skill-nad.

Äldre patienter (>60 år) löper en ökad risk att undertriageras med både gamla och nya kriterier och det föreligger en trend att patienter utsatta för fall-trauma har en ökad risk att undertriageras.

Acknowledgements

I would like to express my sincere gratitude and appreciation to:

Kevin Mani, my main supervisor, for embarking on this journey with me and for always making time to plan, perform, read and revise. For expanding your comfort-zone by supervising me in the field of trauma research, and your gen-erous advice, guidance and tireless efforts to share your clear perspectives and scientific knowledge. I would also like to thank you for your friendship and support in both clinical and scientific matters.

Hampus Eklöf, my co-supervisor, for believing in me, providing generous support and for introducing me to your world-renowned colleagues. You have always been supportive, generous and including and your enthusiasm has been a great inspiration.

Claes Juhlin, my co-supervisor and former head of the department of Surgery at Uppsala University Hospital, for your immense support and believing in me. You have been a true inspiration in choosing trauma and acute care sur-gery as a profession, and your honest attack-relaxed personality which puzzled me at first, is now a refreshing and emphatic trait I hold dear. Your ability to inspire and include young doctors and to make them rise to the occasion is a bold and generous stance. Your leadership has brought me both experience and joy.

Martin Björck, my co-supervisor and professor of vascular surgery, for tak-ing me under your wings all the way from the first five years of residency, followed by my doctoral studies. For sharing your immense knowledge in a most generous manner, and for your support. You are an inspiration in re-search, education and surgery and your stories are fantastic.

Kristiina Kask, head of the department of Surgery at Uppsala University Hospital, for giving me the opportunity and means to produce this thesis.

My co-authors, for joining in on collaborations; Erik Wiklund, Seppo K Koskinen, Per-Erik Åslund, Lina Holmberg, Knut Thorbjörnsen, Jan Wisinger and Per Polleryd. Your support reaches well beyond the scientific

process, and I treasure our discussions on every matter and look forward to future collaborations. The acute care surgery and trauma team of Uppsala, Håkan Andreasson, Mi-kael Ljungdahl, Eladio Cabrera, Arne Eklund, John Ericsson, Maria Jo-hansson and Peter Moberger. You can make bricks without straw. My fellow Ph.D. students at the department of Surgery; Malin Enblad, Jose-fine Kjaer, Christopher Månsson, Martin Skogar. Have fun, and remem-ber: Skiing and writing goes like glue. My younger colleagues at the department of Surgery; Nina Farrokhnia, Hen-rik Benoni, Sara Artursson, Maria Söderström, Janniz Jönsson, Mathilda Annebäck, Tobias Åkerström. Teaching you is both rewarding and challenging and to see you grow and succeed is a great thing. The trauma group, Monica Frick-Bergström, Marie Ellmin, Mattias Wahl-borg, Anders Lewén, Per Enblad, Anneli Rask, Johan Danielsson, Jan Andersson, David Smekal, Magnus von Seth, Petter Schiller. Your endless efforts to improve trauma-care both locally and nationally are exceptional and your work with SweTrau made this thesis possible. All love to my close friends and colleagues, Olov Norlén, Mats Ahlberg, Gunnar Victorin and Linda Adwall. You never grow tired of talking shop, but luckily you also never grow tired of skiing, after-ski, other parties, kidding around and sharing the challenges of life. You are living proof that adults never really grow up, and that is so reassuring. Round Table 125 Uppsala-Fyris, for friendship, support, sharing life’s ups- and downs, and being there for each other. Adopt, Adapt, Improve. My father, for lovingly raising us to believe everything is possible, and prov-ing it once in a while just to make a point (like passing the European astronaut selection), and my mother, for endless support and encouragement in every-thing we do and for inspiration on how to succeed in life. Gustav Linder, for being an excellent surgeon, researcher, college, friend and kid brother. You can be my wingman anytime. Johan and Susanna, my siblings for love, sup-port and friendship. My family: Louise, Ella, Agnes and Gunnar for endless love, encouragement and support. You are my pride and joy, I love you forever and now that I’m finished with my project you get to choose the next one. Is it the bathrooms?

References

1. Socialstyrelsen. Dödsorsaker 2014/Causes of death 2014. 2015. 2. World health organization. Global status report on road safety. Geneva: WHO;

2015. 3. Lossius HM, Langhelle A, Soreide E, Pillgram-Larsen J, Lossius TA, Laake P, et

al. Reporting data following major trauma and analysing factors associated with outcome using the new Utstein style recommendations. Resuscitation. 2001;50(3):263-72.

4. Munroe AR. Baron Larrey-Surgeon General to Napoleon's Army. Canadian Medical Association journal. 1943;48(2):145-8.

5. Brewer LA, 3rd. Baron Dominique Jean Larrey (1766-1842). Father of modern military surgery, innovater, humanist. The Journal of thoracic and cardiovascular surgery. 1986;92(6):1096-8.

6. Soubiran A. [Dominique Larrey 1766-1842]. Revue de chirurgie orthopedique et reparatrice de l'appareil moteur. 1971;57:Suppl 1:11-3.

7. Skandalakis PN, Lainas P, Zoras O, Skandalakis JE, Mirilas P. "To afford the wounded speedy assistance": Dominique Jean Larrey and Napoleon. World journal of surgery. 2006;30(8):1392-9.

8. Bowlby A, Wallace C. THE DEVELOPMENT OF BRITISH SURGERY AT THE FRONT. British medical journal. 1917;1(2944):705-21.

9. Bernheim BM. Management of vascular injuries. S Clin North America. 1942(22):1417-26.

10. DeBakey ME, Simeone FA. Battle Injuries of the Arteries in World War II : An Analysis of 2,471 Cases. Annals of Surgery. 1946;123(4):534-79.

11. Rich NM, Baugh JH, Hughes CW. Acute arterial injuries in Vietnam: 1,000 cases. The Journal of trauma. 1970;10(5):359-69.

12. Collicott PE. Advanced trauma life support course, an improvement in rural trauma care. The Nebraska medical journal. 1979;64(9):279-80.

13. Rotondo MF. About Advanced Trauma Life Support: American College of Surgeons; 2016 [https://www.facs.org/quality-programs/trauma/atls/about].

14. Beal RW. The rational use of blood. The Australian and New Zealand journal of surgery. 1976;46(4):309-13.

15. Mohr R, Martinowitz U, Lavee J, Amroch D, Ramot B, Goor DA. The hemostatic effect of transfusing fresh whole blood versus platelet concentrates after cardiac operations. The Journal of thoracic and cardiovascular surgery. 1988;96(4):530-4.

16. duch*esne JC, Hunt JP, Wahl G, Marr AB, Wang YZ, Weintraub SE, et al. Review of current blood transfusions strategies in a mature level I trauma center: were we wrong for the last 60 years? The Journal of trauma. 2008;65(2):272-6; discussion 6-8.

17. Stone HH, Strom PR, Mullins RJ. Management of the major coagulopathy with onset during laparotomy. Ann Surg. 1983;197(5):532-5.

18. Rotondo MF, Schwab CW, McGonigal MD, Phillips GR, 3rd, Fruchterman TM, Kauder DR, et al. 'Damage control': an approach for improved survival in exsanguinating penetrating abdominal injury. The Journal of trauma. 1993;35(3):375-82; discussion 82-3.

19. Lauer OG. Radiography in the United States Army during World War I. Radiologic technology. 1985;56(6):400-8.

20. Thomas AM. The first 50 years of military radiology 1895-1945. European journal of radiology. 2007;63(2):214-9.

21. Guy JM. Edith (1869-1938) and Florence (1870-1932) Stoney, two Irish sisters and their contribution to radiology during the World War I. Journal of medical biography. 2013;21(2):100-7.

22. Tso P, Rodriguez A, Cooper C, Militello P, Mirvis S, Badellino MM, et al. Sonography in blunt abdominal trauma: a preliminary progress report. The Journal of trauma. 1992;33(1):39-43; discussion -4.

23. Scalea TM, Rodriguez A, Chiu WC, Brenneman FD, Fallon WF, Jr., Kato K, et al. Focused Assessment with Sonography for Trauma (FAST): results from an international consensus conference. The Journal of trauma. 1999;46(3):466-72.

24. Leidner B, Adiels M, Aspelin P, Gullstrand P, Wallen S. Standardized CT examination of the multitraumatized patient. Eur Radiol. 1998;8(9):1630-8.

25. Rizzo AG, Steinberg SM, Flint LM. Prospective assessment of the value of computed tomography for trauma. The Journal of trauma. 1995;38(3):338-42; discussion 42-3.

26. Radon J. Uber die Bestimmung von Funktionen durch ihre Integralwerte Langs Gewisser Mannigfaltigkeiten. Ber Saechsische Akad Wiss. 1917;29:262.

27. Hounsfield GN. Computerized transverse axial scanning (tomography). 1. Description of system. The British journal of radiology. 1973;46(552):1016-22.

28. Walgate R. 35th prize for inventor of EMI X-ray scanner. Nature. 1979;281(5732):512.

29. Leidner B, Adiels M, Aspelin P. [Computer tomography. Life-threatening injuries of the skull, thorax, abdomen and pelvis are diagnosed in 15 minutes]. Lakartidningen. 1994;91(12):1191, 4-6.

30. Ott M, McAlister J, VanderKolk WE, Goldsmith A, Mattice C, Davis AT. Radiation exposure in trauma patients. The Journal of trauma. 2006;61(3):607-9; discussion 9-10.

31. Hui CM, MacGregor JH, Tien HC, Kortbeek JB. Radiation dose from initial trauma assessment and resuscitation: review of the literature. Canadian journal of surgery Journal canadien de chirurgie. 2009;52(2):147-52.

32. Ahmadinia K, Smucker JB, Nash CL, Vallier HA. Radiation exposure has increased in trauma patients over time. The journal of trauma and acute care surgery. 2012;72(2):410-5.

33. Lamki N, Raval B. The role of computed tomography in abdominal and pelvic trauma. The Journal of computed tomography. 1982;6(2):113-9.

34. Gupta M, Schriger DL, Hiatt JR, Cryer HG, Tillou A, Hoffman JR, et al. Selective use of computed tomography compared with routine whole body imaging in patients with blunt trauma. Annals of emergency medicine. 2011;58(5):407-16.e15.

35. Huber-Wagner S, Lefering R, Qvick LM, Korner M, Kay MV, Pfeifer KJ, et al. Effect of whole-body CT during trauma resuscitation on survival: a retrospective, multicentre study. Lancet. 2009;373(9673):1455-61.

36. Stormann P, Gartner K, Wyen H, Lustenberger T, Marzi I, Wutzler S. Epidemiology and outcome of penetrating injuries in a Western European urban

region. European journal of trauma and emergency surgery : official publication of the European Trauma Society. 2016.

37. Laack TA, Thompson KM, Kofler JM, Bellolio MF, Sawyer MD, Laack NN. Comparison of trauma mortality and estimated cancer mortality from computed tomography during initial evaluation of intermediate-risk trauma patients. The Journal of trauma. 2011;70(6):1362-5.

38. Cowley RA. A total emergency medical system for the State of Maryland. Maryland state medical journal. 1975;24(7):37-45.

39. Trunkey DD. Trauma. Accidental and intentional injuries account for more years of life lost in the U.S. than cancer and heart disease. Among the prescribed remedies are improved preventive efforts, speedier surgery and further research. Scientific American. 1983;249(2):28-35.

40. Clark DE, Qian J, Sihler KC, Hallagan LD, Betensky RA. The distribution of survival times after injury. World journal of surgery. 2012;36(7):1562-70.

41. Demetriades D, Kimbrell B, Salim A, Velmahos G, Rhee P, Preston C, et al. Trauma deaths in a mature urban trauma system: is "trimodal" distribution a valid concept? Journal of the American College of Surgeons. 2005;201(3):343-8.

42. McCoy CE, Chakravarthy B, Lotfipour S. Guidelines for Field Triage of Injured Patients: In conjunction with the Morbidity and Mortality Weekly Report published by the Center for Disease Control and Prevention. The western journal of emergency medicine. 2013;14(1):69-76.

43. MacKenzie EJ, Rivara FP, Jurkovich GJ, Nathens AB, Frey KP, Egleston BL, et al. A national evaluation of the effect of trauma-center care on mortality. N Engl J Med. 2006;354(4):366-78.

44. Trauma. ACoSCo. Resources for Optimal Care of the Injured Patient. Chicago, IL2014.

45. Kohn MA, Hammel JM, Bretz SW, Stangby A. Trauma team activation criteria as predictors of patient disposition from the emergency department. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine. 2004;11(1):1-9.

46. Lehmann RK, Arthurs ZM, Cuadrado DG, Casey LE, Beekley AC, Martin MJ. Trauma team activation: simplified criteria safely reduces overtriage. American journal of surgery. 2007;193(5):630-4; discussion 4-5.

47. Henry MC, Hollander JE, Alicandro JM, Cassara G, O'Malley S, Thode HC, Jr. Incremental benefit of individual American College of Surgeons trauma triage criteria. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine. 1996;3(11):992-1000.

48. Dehli T, Fredriksen K, Osbakk SA, Bartnes K. Evaluation of a university hospital trauma team activation protocol. Scandinavian journal of trauma, resuscitation and emergency medicine. 2011;19:18.

49. Baker SP, O'Neill B, Haddon W, Jr., Long WB. The injury severity score: a method for describing patients with multiple injuries and evaluating emergency care. The Journal of trauma. 1974;14(3):187-96.

50. Baker SP, O'Neill B. The injury severity score: an update. The Journal of trauma. 1976;16(11):882-5.

51. Rating the severity of tissue damage. I. The abbreviated scale. Jama. 1971;215(2):277-80.

52. The Abbreviated Injury Scale 2005, Update 2008. Association for the Advancement of Automotive Medicine; 2008.

53. Osler T, Baker SP, Long W. A modification of the injury severity score that both improves accuracy and simplifies scoring. The Journal of trauma. 1997;43(6):922-5; discussion 5-6.

54. Deng Q, Tang B, Xue C, Liu Y, Liu X, Lv Y, et al. Comparison of the Ability to Predict Mortality between the Injury Severity Score and the New Injury Severity Score: A Meta-Analysis. International journal of environmental research and public health. 2016;13(8).

55. Peng J, Xiang H. Trauma undertriage and overtriage rates: are we using the wrong formulas? The American journal of emergency medicine. 2016;34(11):2191-2.

56. Kritsaneepaiboon S, Jutiyon A, Krisanachinda A. Cumulative radiation exposure and estimated lifetime cancer risk in multiple-injury adult patients undergoing repeated or multiple CTs. European journal of trauma and emergency surgery : official publication of the European Trauma Society. 2016.

57. Valentin J. Low-dose extrapolation of radiation-related cancer risk. Annals of the ICRP. 2005;35(4):1-140.

58. Strålskyddsmyndigheten. The Swedish Radiation Safety Authority’s Regulations on General Obligations in Medical and Dental Practices using Ionising Radiation. Stockholm; 2008. Report No.: SSMFS: 2008:35.

59. Sava J, Alo K, Velmahos GC, Demetriades D. All patients with truncal gunshot wounds deserve trauma team activation. The Journal of trauma. 2002;52(2):276-9.

60. Rehn M, Eken T, Kruger AJ, Steen PA, Skaga NO, Lossius HM. Precision of field triage in patients brought to a trauma centre after introducing trauma team activation guidelines. Scandinavian journal of trauma, resuscitation and emergency medicine. 2009;17:1.

61. Eastridge BJ, Owsley J, Sebesta J, Beekley A, Wade C, Wildzunas R, et al. Admission physiology criteria after injury on the battlefield predict medical resource utilization and patient mortality. The Journal of trauma. 2006;61(4):820-3.

62. Mathieu L, Marty A, Ramaki A, Najib A, Ahmadzai W, Fugazzotto DJ, et al. Current issues with lower extremity amputations in a country at war: experience from the National Military Hospital of Kabul. European journal of trauma and emergency surgery : official publication of the European Trauma Society. 2014;40(3):387-93.

63. Yanmaz-Tuzel O, Ozbay K. A comparative Full Bayesian before-and-after analysis and application to urban road safety countermeasures in New Jersey. Accident; analysis and prevention. 2010;42(6):2099-107.

64. Kehoe A, Smith JE, Edwards A, Yates D, Lecky F. The changing face of major trauma in the UK. Emergency medicine journal : EMJ. 2015;32(12):911-5.

65. Cook CH, Muscarella P, Praba AC, Melvin WS, Martin LC. Reducing overtriage without compromising outcomes in trauma patients. Archives of surgery (Chicago, Ill : 1960). 2001;136(7):752-6.

66. Davis JW, Dirks RC, Sue LP, Kaups KL. Attempting to validate the over/under triage matrix at a level I trauma center. The journal of trauma and acute care surgery. 2017.

67. Dehli T, Monsen SA, Fredriksen K, Bartnes K. Evaluation of a trauma team activation protocol revision: a prospective cohort study. Scandinavian journal of trauma, resuscitation and emergency medicine. 2016;24(1):105.

68. Granstrom A, Strommer L, Schandl A, Ostlund A. A criteria-directed protocol for in-hospital triage of trauma patients. European journal of emergency medicine : official journal of the European Society for Emergency Medicine. 2018;25(1):25-31.

69. van Laarhoven JJ, Lansink KW, van Heijl M, Lichtveld RA, Leenen LP. Accuracy of the field triage protocol in selecting severely injured patients after high energy trauma. Injury. 2014;45(5):869-73.

70. Brown JB, Stassen NA, Bankey PE, Sangosanya AT, Cheng JD, Gestring ML. Mechanism of injury and special consideration criteria still matter: an evaluation of the National Trauma Triage Protocol. The Journal of trauma. 2011;70(1):38-44; discussion -5.

71. Rehn M, Lossius HM, Tjosevik KE, Vetrhus M, Ostebo O, Eken T. Efficacy of a two-tiered trauma team activation protocol in a Norwegian trauma centre. Br J Surg. 2012;99(2):199-208.

72. Curtis K, Olivier J, Mitchell R, Cook A, Rankin T, Rana A, et al. Evaluation of a tiered trauma call system in a level 1 trauma centre. Injury. 2011;42(1):57-62.

73. Shawhan RR, McVay DP, Casey L, Spears T, Steele SR, Martin MJ. A simplified trauma triage system safely reduces overtriage and improves provider satisfaction: a prospective study. American journal of surgery. 2015;209(5):856-62; discussion 62-3.

74. van Rein EAJ, Houwert RM, Gunning AC, Lichtveld RA, Leenen LPH, van Heijl M. Accuracy of prehospital triage protocols in selecting severely injured patients: A systematic review. The journal of trauma and acute care surgery. 2017;83(2):328-39.

75. Hemming K, Haines TP, Chilton PJ, Girling AJ, Lilford RJ. The stepped wedge cluster randomised trial: rationale, design, analysis, and reporting. BMJ (Clinical research ed). 2015;350:h391.

76. van de Glind I, Berben S, Zeegers F, Poppen H, Hoogeveen M, Bolt I, et al. A national research agenda for pre-hospital emergency medical services in the Netherlands: a Delphi-study. Scandinavian journal of trauma, resuscitation and emergency medicine. 2016;24:2.

77. Jenkins P, Rogers J, Kehoe A, Smith JE. An evaluation of the use of a two-tiered trauma team activation system in a UK major trauma centre. Emergency medicine journal : EMJ. 2015;32(5):364-7.

78. Kouzminova N, Shatney C, Palm E, McCullough M, Sherck J. The efficacy of a two-tiered trauma activation system at a level I trauma center. The Journal of trauma. 2009;67(4):829-33.

79. Smith J, Lynch J, Sugrue M, Caldwell E, Jalaludin B, Sisson G, et al. An evaluation of compliance with practice guidelines on interhospital trauma transfer. Injury. 2005;36(9):1051-7.

80. Tignanelli CJ, Vander Kolk WE, Mikhail JN, Delano MJ, Hemmila MR. Noncompliance with American College of Surgeons Committee on Trauma recommended criteria for full trauma team activation is associated with undertriage deaths. The journal of trauma and acute care surgery. 2018;84(2):287-94.

81. Miller P, Coffey F, Reid AM, Stevenson K. Can emergency nurses use the Canadian cervical spine rule to reduce unnecessary patient immobilisation? Accident and emergency nursing. 2006;14(3):133-40.

82. Brattström O. Anual report from the swedish trauma registry (SweTrau) 2016 http://rcsyd.se/swetrau/wp-content/uploads/sites/10/2017/10/%C3%85rsrapport-SweTrau-2016_v_2.0_SKL.pdf2017 [

83. Hauswald M, Ong G, Tandberg D, Omar Z. Out-of-hospital spinal immobilization: its effect on neurologic injury. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine. 1998;5(3):214-9.

Appendix

The survey form in paper II

Dear Doctor,

All of the questions below relate to the hospital that you are currently working at. 1. In what country is your hospital located? (obligatorisk)

2. Please select below what kind of hospital you are currently working at:

□ University hospital □ District hospital □ Local hospital (obligatorisk)

3. Name of your hospital? * (obligatorisk) *This question will make it possible for us to see what hospitals that have given answers. Results will be compared on country and region level, hospital name will be anonymized 4. How many WBCTT (Whole-Body Computed Tomography for Trauma) do you

estimate that your Radiology Department performs? □ Fewer than 1 per week □ 1 – 3 per week □ 4 – 6 per week □ About 1 per day □ 1 – 3 per day □ 4 – 6 per day □ More than 6 per day

4. Does your Emergency Department / local ambulance service have an ‘alert’ policy

for trauma patients? □ Yes

□ No

□ Don’t know

5. Does your Emergency Department have a policy regarding the use of whole-body

CT (also called major-trauma CT / pan-CT) for trauma patients? □ Yes – Departmental policy Please go to question 7

□ Yes – Trust-wide policy Please go to question 7

□ No - But use WBCT for trauma Please go to question 6

□ No Please go to question 6 □ Don’t know Please go to question 6

6. Is your hospital currently in the process of defining guidelines for WBCT □ Yes Please go to question □ No Please go to question

7. What criteria are considered to decide which trauma patients undergo whole-body CT? (please tick as many as apply)

□ Mechanism of injury □ Abnormal vital signs □ Anatomical site of injury □ Presence of multiple injuries □ Modified Early Warning Score (MEWS) or similar □ Other If other, please specify _________________________________________________ ________________________________________________________________________ 10. If whole-body CT is deemed necessary, when is it usually performed? □ On patient’s arrival, before assessment □ As part of the primary survey □ After the primary survey □ As part of the secondary survey □ After the secondary survey □ Other If other, please specify _________________________________________________ ________________________________________________________________________

Before assessment = before first clinical examination As part of the primary survey = During the first clinical examination Secondary survey = Reexamination of the patient after the first clinical examination 8. Who usually reports CT in-hours for trauma patients? □ Radiology consultant/attending □ Radiology resident* □ Either □ Other If other, please specify _________________________________________________ ________________________________________________________________________ * Resident = doctor training to become a specialist 9. Who usually reports CT out-of-hours for trauma patients? □ Radiology consultant/attending □ Radiology resident* □ Either □ Other If other, please specify _________________________________________________ ________________________________________________________________________ * Resident = doctor training to become a specialist 10. If the primary report is made by a resident, is the final report made by a

radiology consultant/attending? □ Yes □ No □ Other, please specify

11. How are results of the WBCTT-scan reported to the doctor in charge of the

trauma? (please tick as many as apply) □ Orally □ Written in trauma journal

□ Provisional and final radiology-report □ One report, final answer □ Other, please specify

If other, please specify _________________________________________________ ________________________________________________________________________ 12. The following six subquestions concerns your WBCTT-protocol. Please tick

the boxes below to describe how the images are visualized for each body-part. a. Head □ Without contrast media □ Arterial phase □ Venous phase b. Neck □ Without contrast media □ Arterial phase □ Venous phase c. Thorax □ Without contrast media □ Arterial phase □ Venous phase d. Upper abdomen □ Without contrast media □ Arterial phase □ Venous phase □ Excretory phase e. Lower abdomen (incl. pelvis) □ Without contrast media □ Arterial phase □ Venous phase □ Excretory phase

f. Lower extremity □ This body-part is not included routinely □ Without contrast media □ Arterial phase □ Venous phase

13. How are the patient’s arms aligned when performing WBCTT?

□ Above head if possible during the whole scan □ Parallel to the body during the whole scan □ Arms parallel to the body during scan of head and neck, arms above head when scanning thorax-abdomen □ On the patient’s chest □ Don’t know □ Other, please specify

14. Is the CT located adjacent* to or inside the emergency department?

□ Yes, please describe: □ No □ No, but there are plans for relocating the CT closer to or inside the ED

* Adjacent= same floor and within 50 meters of trauma room. 15. Please specify the average total DLP (dose length product) measured in

mGycm for the complete examination (WBCTT). If needed please consult the medical physicist at your hospital to help you answer this question.

16. Do you think there is a need for national/international WBCTT-guidelines? □ Yes □ No Other: (free-text response) 17. Would your department be willing to adjust to guidelines for WBCTT including

indications and CT scanning protocol? □ Yes

□ NoOther: (Free-text response)

18. Any additional comments?

There are no further questions. Thank you for taking the time to complete this questionnaire.

Acta Universitatis UpsaliensisDigital Comprehensive Summaries of Uppsala Dissertationsfrom the Faculty of Medicine 1431

Editor: The Dean of the Faculty of Medicine

A doctoral dissertation from the Faculty of Medicine, UppsalaUniversity, is usually a summary of a number of papers. A fewcopies of the complete dissertation are kept at major Swedishresearch libraries, while the summary alone is distributedinternationally through the series Digital ComprehensiveSummaries of Uppsala Dissertations from the Faculty ofMedicine. (Prior to January, 2005, the series was publishedunder the title “Comprehensive Summaries of UppsalaDissertations from the Faculty of Medicine”.)

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Trauma - Diagnostics and Triage - uu .diva - [PDF Document] (2024)

FAQs

What are the 4 steps of trauma triage? ›

EMS, emergency medical service. All steps of the current guideline (step 1: physiological parameters; step 2: anatomic factors; step 3: mechanisms of injury; step 4: special considerations) were used in local protocols (step 1 89%, step 2 94%, step 3 93%, and step 4 90%).

Read The Full Story ›

What is step 3 of the CDC trauma triage guidelines? ›

There are four steps to the triage process: Step One: Physiologic Criteria, Step Two: Anatomic Criteria, Step Three: Mechanism-of-Injury Criteria, and Step Four: Special Considerations.

View Details ›

What is the triage system for trauma? ›

The triage sort or Revised Trauma Score (RTS)

It is a common physiological scoring system based on the first data sets of three specific physiological parameters obtained from the patient. The three parameters are: the GCS, systemic blood pressure (SBP), and the respiratory rate (RR).

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What is the trauma score triage? ›

Use in triage

The Revised Trauma Score is made up of three categories: Glasgow Coma Scale, systolic blood pressure, and respiratory rate. The score range is 0–12. In START triage, a patient with an RTS score of 12 is labeled delayed, 11 is urgent, and 3–10 is immediate.

What are the 5 S's of triage? ›

The keys to successfully managing the chaos of a fast-paced, moving MCI can be delineated with the organization of the 5 “S's”: “scene safety assessment, scene size-up, send information, scene set-up, and START (Simple Triage and Rapid Treatment).”

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What are the 4 P's of trauma? ›

The 4 Ps is a worksheet designed for the trauma informed care workshop. The 4 Ps looks at four domains which may be impacted through experiences of trauma – physical, psychological, performance and people.

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What is the trauma triage protocol? ›

OLMC considers patient transport to Trauma Center, using following guidelines: a) If transport time by ground or air to Trauma Center is less than 30 minutes, patient should go to Trauma Center directly; b) If transport time to Trauma Center is greater than 30 minutes, determine the difference in transport time between ...

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What is the national trauma triage tool? ›

Description: The Trauma Triage Tool is based on three components: injuries, physiology and mechanism. A positive result in any component means the patient meets MTC criteria and patient disposition should be as described in the Trauma Access Protocol.

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What is the difference between triage 3 and 4? ›

If the patient requires two or more hospital resources, the patient is triaged as a level 3. If the patient needs one hospital resource, the patient would be labeled a 4. If the patient does not need any hospital resources, the patient would be labeled a 5.

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What is triage pdf? ›

Triage is a system used in emergency when the number of injured needing care exceeds the. resources available to perform care so as to treat the greatest number of patient poss.

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What are the colors for triage trauma? ›

The 4 conventional triage categories are:

Minor: Green Triage Tag Color. Victim with relatively minor injuries. ...
Delayed: Yellow Triage Tag Color. Victim's transport can be delayed. ...
Immediate: Red Triage Tag Color. Victim can be helped by immediate intervention and transport. ...
Expectant: Black Triage Tag Color.

What are the 5 levels of triage? ›

In general, the triage system has five levels:

Level 1 – Immediate: life threatening.
Level 2 – Emergency: could become life threatening.
Level 3 – Urgent: not life threatening.
Level 4 – Semi-urgent: not life threatening.
Level 5 – Non-urgent: needs treatment when time permits.

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How do you assess triage? ›

Triage of patients involves looking for signs of serious illness or injury. These emergency signs are connected to the Airway - Breathing - Circulation/Consciousness - Dehydration and are easily remembered as ABCD.

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What is the best trauma scoring system? ›

The Glasgow coma score has the greatest prognostic value in head-injured and other trauma patients.

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What is the priority assessment for a trauma patient? ›

Advanced Trauma Life Support (ATLS), developed by the American College of Surgeons, promotes the primary survey sequence as airway, breathing, circulation, disability, exposure (ABCDE). Once the airway is secured or maintained by the patient, breathing and ventilation should be assessed.

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What are the 4 principles of triage? ›

Some of the main indicators of triage principles include prioritizing the injured people, the duration of triage, the accuracy of triage, and the factors causing injuries, which have been considered in different systems of triage world-wide.

Trauma - Diagnostics and Triage - uu .diva - [PDF Document] (2024)

FAQs

What are the 4 steps of trauma triage? ›

What are the colors for triage trauma? ›

References