Coagulopathy Underlying Rotational Thromboelastometry Derangements in Trauma Patients: A Prospective Observational Multicenter Study.

BACKGROUND: Viscoelastic hemostatic assays such as rotational thromboelastometry (ROTEM) are used to guide treatment of trauma induced coagulopathy. The authors hypothesized that ROTEM derangements reflect specific coagulation factor deficiencies after trauma. METHODS: This was a secondary analysis of a prospective cohort study in six European trauma centers in patients presenting with full trauma team activation. Patients with dilutional coagulopathy and patients on anticoagulants were excluded. Blood was drawn on arrival for measurement of ROTEM, coagulation factor levels, and markers of fibrinolysis. ROTEM cutoff values to define hypocoagulability were as follows: EXTEM clotting time greater than 80 s, EXTEM clot amplitude at 5 min less than 40 mm, EXTEM lysis index at 30 min less than 85%, FIBTEM clot amplitude at 5 min less than 10 mm, and FIBTEM lysis index at 30 min less than 85%. Based on these values, patients were divided into seven deranged ROTEM profiles and compared to the reference group (ROTEM values within reference range). The primary endpoint was coagulation factors levels and fibrinolysis. RESULTS: Of 1,828 patients, 732 (40%) had ROTEM derangements, most often consisting of a combined decrease in EXTEM and FIBTEM clot amplitude at 5 min, that was present in 217 (11.9%) patients. While an isolated EXTEM clotting time greater than 80 s had no impact on mortality, all other ROTEM derangements were associated with increased mortality. Also, coagulation factor levels in this group were similar to those of patients with a normal ROTEM. Of coagulation factors, a decrease was most apparent for fibrinogen (with a nadir of 0.78 g/l) and for factor V levels (with a nadir of 22.8%). In addition, increased fibrinolysis can be present when the lysis index at 30 min is normal but EXTEM and FIBTEM clot amplitude at 5 min is decreased. CONCLUSIONS: Coagulation factor levels and mortality in the group with an isolated clotting time prolongation are similar to those of patients with a normal ROTEM. Other ROTEM derangements are associated with mortality and reflect a depletion of fibrinogen and factor V. Increased fibrinolysis can be present when the lysis index after 30 min is normal.

Exercising for mass casualty preparedness.

Exercising for mass casualty incidents is mandated by governing organisations with the aim of maintaining readiness within the healthcare sector for the many challenges these incidents bring. This readiness is delivered through a combination of discussion-based and operation-based exercises that are targeted to the needs of both the individuals delivering care and the needs of the overall system of patient flow and treatment. Although exercising for disaster preparedness is resource intensive, it is the repetitive, iterative nature that allows for wide staff capture and exposure along with continual improvement of plans. Having been recently involved in exercising is also likely to increase the confidence of staff and makes them feel better prepared. Exercising should be tailored to the needs and likely challenges of each healthcare system. A cycle of design, challenge, and redesign should target areas of greatest need and greatest benefit. The conventional advice, when introducing exercising, is to start small and build up over time with repeated exercises that demonstrate increasing response capability. However, some organisations would benefit from an exercise that lays bare shortcomings and acts to galvanise change.

Learning from terrorist mass casualty incidents: a global survey.

BACKGROUND: Reports published directly after terrorist mass casualty incidents frequently fail to capture difficulties that may have been encountered. An anonymised consensus-based platform may enable discussion and collaboration on the challenges faced. Our aim was to identify where to focus improvement for future responses. METHODS: We conducted a mixed methods study by email of clinicians' experiences of leading during terrorist mass casualty incidents. An initial survey identified features that worked well, or failed to, during terrorist mass casualty incidents plus ongoing challenges and changes that were implemented as a result. A follow-up, quantitative survey measured agreement between responses within each of the themes using a Likert scale. RESULTS: Thirty-three participants responded from 22 hospitals that had received casualties from a terrorist incident, representing 17 cities in low-middle, middle and high income countries. The first survey identified themes of sufficient (sometimes abundant) human resource, although coordination of staff was a challenge. Difficulties highlighted were communication, security, and management of blast injuries. The most frequently implemented changes were education on specific injuries, revising future plans and preparatory exercises. Persisting challenges were lack of time allocated to training and psychological well-being. The follow-up survey recorded highest agreement amongst correspondents on the need for re-triage at hospital (90% agreement), coordination roles (85% agreement), flexibility (100% agreement), and large-scale exercises (95% agreement). CONCLUSION: This survey collates international experience gained from clinicians managing terrorist mass casualty incidents. The organisation of human response, rather than consumption of physical supplies, emerged as the main finding. NHSH Clinical Effectiveness Unit project registration number: 2020/21-036.

Thrombelastography (TEG® 6s) early amplitudes predict maximum amplitude in severely injured trauma patients.

Severely injured trauma patients are often coagulopathic and early hemostatic resuscitation is essential. Previous studies have revealed linear relationships between thrombelastography (TEG®) five- and ten-min amplitudes (A5 and A10), and maximum amplitude (MA), using TEG® 5000 technology. We aimed to investigate the performance of A5 and A10 in predicting low MA in severely injured trauma patients and identify optimal cut-off values for hemostatic intervention based on early amplitudes, using the cartridge-based TEG® 6s technology. Adult trauma patients with hemorrhagic shock were included in the iTACTIC randomized controlled trial at six European Level I trauma centers between 2016 and 2018. After admission, patients were randomized to hemostatic therapy guided by conventional coagulation tests (CCT) or viscoelastic hemostatic assays (VHA). Patients with available admission-TEG® 6s data were included in the analysis, regardless of treatment allocation. Low MA was defined as <55 mm for Kaolin TEG® and RapidTEG®, and <17 mm for TEG® functional fibrinogen (FF). One hundred eighty-seven patients were included. Median time to MA was 20 (Kaolin TEG®), 21 (RapidTEG®) and 12 (TEG® FF) min. For Kaolin TEG®, the optimal Youden index (YI) was at A5 < 36 mm (100/93% sensitivity/specificity) and A10 < 47 mm (100/96% sensitivity/specificity). RapidTEG® optimal YI was at A5 < 34 mm (98/92% sensitivity/specificity) and A10 < 45 mm (96/95% sensitivity/specificity). TEG® FF optimal YI was at A5 < 12 mm (97/93% sensitivity/specificity) and A10 < 15 mm (97/99% sensitivity/specificity). In summary, we found that TEG® 6s early amplitudes were sensitive and specific predictors of MA in severely injured trauma patients. Intervening on early amplitudes can save valuable time in hemostatic resuscitation.

Shock-Driven Endotheliopathy in Trauma Patients Is Associated with Leucocyte Derived Extracellular Vesicles.

Endotheliopathy following trauma is associated with poor outcome, but the underlying mechanisms are unknown. This study hypothesized that an increased extracellular vesicle (EV) concentration is associated with endotheliopathy after trauma and that red blood cell (RBC) transfusion could further enhance endotheliopathy. In this post hoc sub study of a multicentre observational trial, 75 trauma patients were stratified into three groups based on injury severity score or shock. In patient plasma obtained at hospital admission and after transfusion of four RBC transfusions, markers for endotheliopathy were measured and EVs were labelled with anti CD41 (platelet EVs), anti CD235a (red blood cell EVs), anti CD45 (leucocyte EVs), anti CD144 (endothelial EVs) or anti CD62e (activated endothelial EVs) and EV concentrations were measured with flow cytometry. Statistical analysis was performed by a Kruskall Wallis test with Bonferroni correction or Wilcoxon rank test for paired data. In patients with shock, syndecan-1 and von Willebrand Factor (vWF) were increased compared to patients without shock. Additionally, patients with shock had increased red blood cell EV and leucocyte EV concentrations compared to patients without shock. Endotheliopathy markers correlated with leucocyte EVs (ρ = 0.263, p = 0.023), but not with EVs derived from other cells. Injury severity score had no relation with EV release. RBC transfusion increased circulating red blood cell EVs but did not impact endotheliopathy. In conclusion, shock is (weakly) associated with EVs from leucocytes, suggesting an immune driven pathway mediated (at least in part) by shock.

Young adults in motor vehicle collisions in Norway: user safety errors observed in majority of cases with severe or fatal injuries.

PURPOSE: We performed a multidisciplinary investigation of young adults involved in motor vehicle collisions (MVCs) to elucidate injury mechanisms and the role of passive safety equipment such as seat belts and airbags. METHODS: MVCs resulting in death or serious injuries to the driver or passengers aged 16-24 years in southeastern Norway during 2013-2016 were investigated upon informed consent. We assessed the crash scene, the motor vehicle (MV) interior and exterior, and analyzed data from medical records, forensic autopsies and reports from police and civil road authorities. RESULTS: This study included 229 young adult occupants involved in 212 MVCs. The Maximum Abbreviated Injury Scale (MAIS) score was ≥2 in 111 occupants, of which 22 were fatalities. In 59% (65/111) of the cases with MAIS score ≥2 injuries, safety errors and occupant protection inadequacies were considered to have contributed to the injury outcome. Common errors were seatbelt non-use and misuse, carrying insecure luggage, and the seat back being too reclined. MAIS score ≥2 head/neck injuries were observed in side impacts despite correct seatbelt use, related to older MVs lacking side airbag curtains. The independent risk factors for MAIS score ≥2 injuries included not using a seatbelt, driving under the influence of alcohol or drugs, nighttime driving, side impacts, heavy collision partner, and MV deformation. CONCLUSION: User safety errors (not using a seatbelt, seatbelt misuse, excessive seat-back reclining, and insecure cargo) and a lack of occupant protection in older MVs resulted in young adults sustaining severe or fatal injuries in MVCs.

Efficacy and safety of iloprost in trauma patients with haemorrhagic shock-induced endotheliopathy-Protocol for the multicentre randomized, placebo-controlled, blinded, investigator-initiated shine-trauma trial.

BACKGROUND: Traumatic injury accounts for 800 000 deaths in the European Union annually. The main causes of deaths in trauma patients are exsanguination and multiple organ failure (MOF). We have studied >1000 trauma patients and identified shock-induced endotheliopathy (SHINE), the pathophysiological mechanism responsible for MOF and high mortality. Pilot studies indicate that low-dose iloprost (1 ng/kg/min) improves endothelial functionality in critically ill patients suggesting this intervention may improve patient outcome in traumatic SHINE. MATERIAL AND METHODS: This is a multicentre, randomized, blinded clinical investigator-initiated phase 2B trial in trauma patients with haemorrhagic shock-induced endotheliopathy. Patients are randomized 1:1 to 72 hours infusion of iloprost 1 ng/kg/min or Placebo (equal volume of saline). A total of 220 trauma patients will be included. The primary endpoint is the number of intensive care unit (ICU)-free days, within 28 days of admission. Secondary endpoints include 28- and 90-day all-cause mortality, hospital length of stay, vasopressor-free days in the intensive care unit (ICU) within 28 days, ventilator-free days in the ICU within 28 days, renal replacement-free days in the ICU within 28 days, number of serious adverse reactions and serious adverse events within the first 4 days of admission. DISCUSSION: This trial will test the safety and efficacy of administration of iloprost vs placebo for 72 hours in trauma patients with haemorrhagic shock-induced endotheliopathy. Trial endpoints focus on the potential effect of iloprost to reduce the need for ICU stay secondary to mitigation of organ failure. TRIAL REGISTRATION: SHINE-TRAUMA trial-EudraCT no. 2019-000936-24-Clinicaltrials.gov: NCT03903939 Ethics Committee no. H-19014482.

Autopsy findings in drivers and passengers from fatal motor vehicle collisions: limited differences in injury patterns and toxicological test results.

We performed a retrospective study of the injuries and characteristics of occupant fatalities in motor vehicle collisions in southeast Norway. The goal was to provide updated knowledge of injuries sustained in modern vehicles and detect possible differences in injury pattern between drivers and passengers. Forensic autopsy reports, police, and collision investigation reports from 2000 to 2014 were studied, data extracted and analyzed.A total of 284 drivers, 80 front-seat passengers, and 37 rear-seat passengers were included, of which 67.3% died in front collisions, 13.7% in near-side impacts, 13.5% in rollovers and 5.5% in other/combined collisions. Overall, 80.5% died within one hour after the crash. The presence of fatal injuries to the head, neck, thorax and abdomen were observed in 63.6%, 10.7%, 61.6% and 27.4% respectively. All occupants with severe injuries to the head or neck had signs of direct impact with contact point injuries to the skin or skull. Injuries to the heart and spleen were less common in front-seat passengers compared to drivers. Seat belt abrasions were more common and lower extremity fractures less common in both front-seat and rear-seat passengers compared to drivers. Blood alcohol and/or drug concentrations suggestive of impairment were present in 30% of all occupants, with alcohol more often detected among front-seat passengers compared to drivers.Few driver-specific and passenger-specific patterns of injury could be identified. When attempting to assess an occupant's seating position within a vehicle, autopsy findings should be interpreted with caution and only in conjunction with documentation from the crash scene.

Data-driven Development of ROTEM and TEG Algorithms for the Management of Trauma Hemorrhage: A Prospective Observational Multicenter Study.

OBJECTIVE: Developing pragmatic data-driven algorithms for management of trauma induced coagulopathy (TIC) during trauma hemorrhage for viscoelastic hemostatic assays (VHAs). BACKGROUND: Admission data from conventional coagulation tests (CCT), rotational thrombelastometry (ROTEM) and thrombelastography (TEG) were collected prospectively at 6 European trauma centers during 2008 to 2013. METHODS: To identify significant VHA parameters capable of detecting TIC (defined as INR > 1.2), hypofibrinogenemia (< 2.0 g/L), and thrombocytopenia (< 100 x10/L), univariate regression models were constructed. Area under the curve (AUC) was calculated, and threshold values for TEG and ROTEM parameters with 70% sensitivity were included in the algorithms. RESULTS: A total of, 2287 adult trauma patients (ROTEM: 2019 and TEG: 968) were enrolled. FIBTEM clot amplitude at 5 minutes (CA5) had the largest AUC and 10 mm detected hypofibrinogenemia with 70% sensitivity. The corresponding value for functional fibrinogen (FF) TEG maximum amplitude (MA) was 19 mm. Thrombocytopenia was similarly detected using the calculated threshold EXTEM-FIBTEM CA5 30 mm. The corresponding rTEG-FF TEG MA was 46 mm. TIC was identified by EXTEM CA5 41 mm, rTEG MA 64 mm (80% sensitivity). For hyperfibrinolysis, we examined the relationship between viscoelastic lysis parameters and clinical outcomes, with resulting threshold values of 85% for EXTEM Li30 and 10% for rTEG Ly30.Based on these analyses, we constructed algorithms for ROTEM, TEG, and CCTs to be used in addition to ratio driven transfusion and tranexamic acid. CONCLUSIONS: We describe a systematic approach to define threshold parameters for ROTEM and TEG. These parameters were incorporated into algorithms to support data-driven adjustments of resuscitation with therapeutics, to optimize damage control resuscitation practice in trauma.

The S100A10 Pathway Mediates an Occult Hyperfibrinolytic Subtype in Trauma Patients.

OBJECTIVE: To determine the characteristics of trauma patients with low levels of fibrinolysis as detected by viscoelastic hemostatic assay (VHA) and explore the underlying mechanisms of this subtype. BACKGROUND: Hyperfibrinolysis is a central component of acute traumatic coagulopathy but a group of patients present with low levels of VHA-detected fibrinolysis. There is concern that these patients may be at risk of thrombosis if empirically administered an antifibrinolytic agent. METHODS: A prospective multicenter observational cohort study was conducted at 5 European major trauma centers. Blood was drawn on arrival, within 2 hours of injury, for VHA (rotation thromboelastometry [ROTEM]) and fibrinolysis plasma protein analysis including the fibrinolytic mediator S100A10. An outcomes-based threshold for ROTEM hypofibrinolysis was determined and patients grouped by this and by D-dimer (DD) levels. RESULTS: Nine hundred fourteen patients were included in the study. The VHA maximum lysis (ML) lower threshold was determined to be <5%. Heterogeneity existed among patients with low ML, with survivors sharing similar clinical and injury characteristics to patients with normal ML values (5-15%). Those who died were critically injured with a preponderance of traumatic brain injury and had a 7-fold higher DD level (died vs. survived: 103,170 vs. 13,672 ng/mL, P < 0.001). Patients with low ML and high DD demonstrated a hyperfibrinolytic biomarker profile, low tissue plasminogen activator levels but high plasma levels of S100A10. S100A10 was negatively correlated with %ML (r = -0.26, P < 0.001) and caused a significant reduction in %ML when added to whole blood ex-vivo. CONCLUSIONS: Patients presenting with low ML and low DD levels have low injury severity and normal outcomes. Conversely, patients with low ML but high DD levels are severely injured, functionally coagulopathic and have poor clinical outcomes. These patients have low tissue plasminogen activator levels and are not detectable by ROTEM. S100A10 is a cell surface plasminogen receptor which may drive the hyperfibrinolysis in these patients and which when shed artificially lowers %ML ex-vivo.

Incidence of chronic pain 6 y after major trauma.

BACKGROUND: Life saving measures is the main focus in the initial treatment of major trauma. In surviving patients, chronic pain may be a serious problem, but the long term incidence and potential risk factors are not very well studied. METHODS: All adult trauma patients included in the institutional trauma registry in 2007 were assessed for eligibility. Among exclusion criteria were: Injury Severity Score < 9, endotracheal intubation before or during admission, spinal cord lesion, known chronic drug or substance abuse, major surgery within 3 h after admission. A patient questionnaire was sent out 6 y after injury focusing on frequency and intensity of pain. A subgroup analysis was done in patients with thoracic injuries, comparing patients with epidural analgesia (EDA) and patients without. RESULTS: Sixty-eight patients were included in the study. Sixty-nine percent reported pain 6 y after injury and 24% had severe pain. The severity of the injury was a risk factor for development of chronic pain, whereas pain during initial hospital stay was not. In patients with thoracic injuries there was no correlation between initial treatment with EDA and decreased incidence of chronic pain, however patient numbers were small. Opioids were the main analgesics used initially; no patients received non-steroidal anti-inflammatory drugs or peripheral nerve blocks during the first 24 h. CONCLUSION: Two thirds of the trauma patients had chronic pain 6 y after injury and one out of four had severe pain. The initial pain treatment was focused on opioids.

Impact of Trauma System Structure on Injury Outcomes: A Systematic Review and Meta-Analysis.

BACKGROUND: The effectiveness of trauma systems in decreasing injury mortality and morbidity has been well demonstrated. However, little is known about which components contribute to their effectiveness. We aimed to systematically review the evidence of the impact of trauma system components on clinically important injury outcomes. METHODS: We searched MEDLINE, EMBASE, Cochrane CENTRAL, and BIOSIS/Web of Knowledge, gray literature and trauma association Web sites to identify studies evaluating the association between at least one trauma system component and injury outcome. We calculated pooled effect estimates using inverse-variance random-effects models. We evaluated quality of evidence using GRADE criteria. RESULTS: We screened 15,974 records, retaining 41 studies for qualitative synthesis and 19 for meta-analysis. Two recommended trauma system components were associated with reduced odds of mortality: inclusive design (odds ratio [OR] = 0.72 [0.65-0.80]) and helicopter transport (OR = 0.70 [0.55-0.88]). Pre-Hospital Advanced Trauma Life Support was associated with a significant reduction in hospital days (mean difference [MD] = 5.7 [4.4-7.0]) but a nonsignificant reduction in mortality (OR = 0.78 [0.44-1.39]). Population density of surgeons was associated with a nonsignificant decrease in mortality (MD = 0.58 [-0.22 to 1.39]). Trauma system maturity was associated with a significant reduction in mortality (OR = 0.76 [0.68-0.85]). Quality of evidence was low or very low for mortality and healthcare utilization. CONCLUSIONS: This review offers low-quality evidence for the effectiveness of an inclusive design and trauma system maturity and very-low-quality evidence for helicopter transport in reducing injury mortality. Further research should evaluate other recommended components of trauma systems and non-fatal outcomes and explore the impact of system component interactions.

The significance of preexisting medical conditions, alcohol/drug use and suicidal behavior for drivers in fatal motor vehicle crashes: a retrospective autopsy study.

Driver fatalities in motor vehicle collisions (MVCs) encompass accidents, suicides, and natural deaths when driving. The objective of this study was to determine the significance of pathology and other autopsy findings for drivers in fatal MVCs. Forensic autopsy records of driver fatalities in southeast Norway between 2000 and 2014 were studied retrospectively. Data from individual police and collision investigation reports were also collected and analyzed. In 406 driver fatalities, the male/female ratio was 340/66; 9% died from natural causes, 9% were suicides, 65% were culpable accidental deaths, 14% were nonculpable deaths, and 3% were undetermined deaths. Head injuries and thoracic injuries were the most common causes of death. A seatbelt had been worn in 50% of the fatalities, and its prevalence did not differ between accidental deaths and suicides. Blood levels of alcohol and/or drugs that indicated impairment at the time of the collision were found in 40% (105/262) of all culpable accidental deaths but in 50% (64/127) of drivers aged up to 35 years. Pathology (most often cardiovascular disease) suggestive of sudden incapacitation before the collision was present in 24% (62/264) of drivers who were culpable in the accident and in 70% (46/66) of culpable drivers older than 55 years. A substantial proportion of drivers are killed in accidental collisions that may have occurred as a result of either alcohol/drug impairment or preexisting disease. Suicides and natural deaths both constitute significant proportions of MVC fatalities and may be misclassified unless a full inquest including an autopsy is performed.

Radiology response in the emergency department during a mass casualty incident: a retrospective study of the two terrorist attacks on 22 July 2011 in Norway.

OBJECTIVES: To describe the use of radiology in the emergency department (ED) in a trauma centre during a mass casualty incident, using a minimum acceptable care (MAC) strategy in which CT was restricted to potentially severe head injuries. METHODS: We retrospectively studied the initial use of imaging on patients triaged to the trauma centre following the twin terrorist attacks in Norway on 22 July 2011. RESULTS: Nine patients from the explosion and 15 from the shooting were included. Fourteen patients had an Injury Severity Score >15. During the first 15 h, 22/24 patients underwent imaging in the ED. All 15 gunshot patients had plain films taken in the ED, compared to three from the explosion. A CT was performed in 18/24 patients; ten of these were completed in the ED and included five non-head CTs, the latter representing deviations from the MAC strategy. No CT referrals were delayed or declined. Mobilisation of radiology personnel resulted in a tripling of the staff. CONCLUSIONS: Plain film and CT capacity was never exceeded despite deviations from the MAC strategy. An updated disaster management plan will require the radiologist to cancel non-head CTs performed in the ED until no additional MCI patients are expected. KEY POINTS: • Minimum acceptable care (MAC) should replace normal routines in mass casualty incidents. • MAC implied reduced use of imaging in the emergency department (ED). • CT in ED was restricted to suspected severe head injuries during MAC. • The radiologist should cancel all non-head CTs in the ED during MAC.

Spleen and liver injuries: when to operate?

PURPOSE OF REVIEW: Although nonoperative management (NOM) is the safest option in most patients with liver and splenic injuries or splenic injuries, some cases still need operative intervention. The aim of this review is to address the most recent literature and the evidence it provides for indications and timing of operative treatment for liver and spleen injuries. RECENT FINDINGS: There seems to be a decrease in publication rate on these topics over the last years, parallel to the acceptance of NOM as the 'gold standard', with little added to the existing body of evidence over the last 12-24 months. Most published studies are retrospective descriptions or comparisons with historical controls, some observational studies, but no randomized control trials (RCTs).There is a striking lack of high-level evidence for the optimal treatment of solid organ injuries. The role of angiographic embolization as an adjunct to the treatment of liver and spleen injuries is still a matter of discussion. SUMMARY: Unstable patients with suspected ongoing bleeding from liver and spleen injuries or spleen injuries with inadequate effect of resuscitation should undergo immediate explorative laparotomy.More RCTs are needed to further determine the role of angiographic embolization and who can be safely be treated nonoperatively and who needs surgical intervention.

Detection of acute traumatic coagulopathy and massive transfusion requirements by means of rotational thromboelastometry: an international prospective validation study.

INTRODUCTION: The purpose of this study was to re-evaluate the findings of a smaller cohort study on the functional definition and characteristics of acute traumatic coagulopathy (ATC). We also aimed to identify the threshold values for the most accurate identification of ATC and prediction of massive transfusion (MT) using rotational thromboelastometry (ROTEM) assays. METHODS: In this prospective international multicentre cohort study, adult trauma patients who met the local criteria for full trauma team activation from four major trauma centres were included. Blood was collected on arrival to the emergency department and analyzed with laboratory international normalized ratio (INR), fibrinogen concentration and two ROTEM assays (EXTEM and FIBTEM). ATC was defined as laboratory INR >1.2. Transfusion requirements of ≥10 units of packed red blood cells within 24 hours were defined as MT. Performance of the tests were evaluated by receiver operating characteristic curves, and calculation of area under the curve (AUC). Optimal cutoff points were estimated based on Youden index. RESULTS: In total, 808 patients were included in the study. Among the ROTEM parameters, the largest AUCs were found for the clot amplitude (CA) 5 value in both the EXTEM and FIBTEM assays. EXTEM CA5 threshold value of ≤37 mm had a detection rate of 66.3% for ATC. An EXTEM CA5 threshold value of ≤40 mm predicted MT in 72.7%. FIBTEM CA5 threshold value of ≤8 mm detected ATC in 67.5%, and a FIBTEM CA5 threshold value ≤9 mm predicted MT in 77.5%. Fibrinogen concentration ≤1.6 g/L detected ATC in 73.6% and a fibrinogen concentration ≤1.90 g/L predicted MT in 77.8%. Patients with either an EXTEM or FIBTEM CA5 below the optimum detection threshold for ATC received significantly more packed red blood cells and plasma. CONCLUSIONS: This study confirms previous findings of ROTEM CA5 as a valid marker for ATC and predictor for MT. With optimum threshold for EXTEM CA5 ≤ 40 mm and FIBTEM CA5 ≤ 9 mm, sensitivity is 72.7% and 77.5% respectively. Future investigations should evaluate the role of repeated viscoelastic testing in guiding haemostatic resuscitation in trauma.

Prevalence, predictors and outcome of hypofibrinogenaemia in trauma: a multicentre observational study.

INTRODUCTION: Exsanguination due to trauma-induced coagulopathy is a continuing challenge in emergency trauma care. Fibrinogen is a crucial factor for haemostatic competence, and may be the factor that reaches critically low levels first. Early fibrinogen substitution is advocated by a number of authors. Little evidence exists regarding the indications for fibrinogen supplementation in the acute phase. This study aims to estimate the prevalence of hypofibrinogenaemia in a multi-center trauma population, and to explore how initial fibrinogen concentration relates to outcome. Also, factors contributing to low fibrinogen levels are identified. METHODS: Patients arriving in hospital less than 180 minutes post-injury requiring full trauma team activation in four different centers were included in the study. Time from injury, patient demographics, injury severity scores (ISS) and 28 days outcome status were recorded. Initial blood samples for coagulation and blood gas were analyzed. Generalized additive regression, piecewise linear regression, and multiple linear regression models were used for data analyses. RESULTS: Out of 1,133 patients we identified a fibrinogen concentration ≤1.5g/L in 8.2%, and <2 g/L in 19.2%. A non-linear relationship between fibrinogen concentration and mortality was detected in the generalized additive and piecewise linear regression models. In the piecewise linear regression model we identified a breakpoint for optimal fibrinogen concentration at 2.29 g/L (95% confidence interval (CI): 1.93 to 2.64). Below this value the odds of death by 28 days was reduced by a factor of 0.08 (95% CI: 0.03 to 0.20) for every unit increase in fibrinogen concentration. Low age, male gender, lengthened time from injury, low base excess and high ISS were unique contributors to low fibrinogen concentrations on arrival. CONCLUSIONS: Hypofibrinogenaemia is common in trauma and strongly associated with poor outcome. Below an estimated critical fibrinogen concentration value of 2.29 g/L a dramatic increase in mortality was detected. This finding indicates that the negative impact of low fibrinogen concentrations may have been previously underestimated. A number of clinically identifiable factors are associated with hypofibrinogenaemia. They should be considered in the management of massively bleeding patients. Interventional trials with fibrinogen substitution in high-risk patients need to be undertaken.