Page 28 - JSOM Winter 2025

Prehospital Fibrinogen Levels in Major Trauma Patients
Transported by Helicopter Emergency Medical Service

Determining Who Might Benefit

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Shannon Pretty, MD ; Domhnall O’Dochartaigh, MSc *; Elfriede Cross, MD ;
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Efrem Violato, PhD ; Julie Zwicker, BSc ; Aliyah Gauri, MSc ; Pete Chen, MD ;
Xenia Cravetchi, MD ; Sandy Widder, MD ; Arabesque Parker, MD ;
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Leandro Solis Aguilar, PhD ; Matthew Douma, MSc ; Eddie Chang, MD 13
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ABSTRACT
Background: Low fibrinogen contributes to poor outcomes in Introduction
patients with traumatic coagulopathy. Empiric fibrinogen re-
placement is not supported. Early identification of patients at Major trauma can cause a multi-factorial coagulopathy that
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high risk of hypofibrinogenemia may enable targeted support. significantly contributes to morbidity and mortality. Fibrin-
We sought to identify prehospital variables associated with ogen promotes stable clot formation but is quickly depleted
hypofibrinogenemia at emergency department (ED) arrival. in major trauma hemorrhage from absolute loss secondary to
Methods: We retrospectively reviewed health records (January hemorrhage, increased consumption, fibrinolysis by plasmin,
2015 to August 2019) of consecutive patients transported by and reduced synthesis. Fibrinogen levels under 1.6g/L are as-
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helicopter EMS to two trauma centers who received one or sociated with poor outcomes.
more units of packed red blood cells (pRBCs) during trans-
port. The primary outcome was first ED fibrinogen level trans- CRYOSTAT-2, a recent high-quality trauma randomized con-
formed into a binomial variable (<1.6g/L or ≥1.6g/L) for the trolled trial, examined early in-hospital empiric high-dose
65 patients analyzed. Direct multivariable logistic regression treatment with fibrinogen replacement given in the form of
examined the independent variables (hypotension, shock in- cryoprecipitate. No difference was found in mortality, second-
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dex (SI), and systolic blood pressure. Odds ratios and 95% CIs ary, or safety outcomes. The authors considered their findings
were reported. Results: Hypotension after first pRBC transfu- not consistent with previous observational, pilot, and feasibil-
sion was significantly associated with low ED first fibrinogen ity RCTs. They hypothesize that some patients who could have
level, P=.03, with 6.6 (1.1–40.15) times greater odds of fibrin- benefited but may not have received cryoprecipitate in time or
ogen <1.6g/L. Hypotension post-transfusion was also associ- at a sufficient dose (average cryoprecipitate initiation was over
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ated with ED first international normalized ratio (INR)>1.5, 1 hour after ED arrival). The consumption of fibrinogen pro-
P=.013, with those cases having 17.5 (1.8–169.2) greater odds gresses quickly during the first hour after trauma; thus, there
of INR >1.5. Additionally, an EDSI ≥1.5 had 8.9 (1.9–42.6) may be a narrow window of opportunity to reverse critical fi-
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times greater odds of fibrinogen <1.6g/L than those with an brinogen depletion. Mrochuk et al. suggest Canadian patients
EDSI <1, P=.006. Compared with the EDSI 1–1.49 group, transported by helicopter EMS (HEMS) may reach this critical
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those with an EDSI≥1.5 had 6.9 times greater odds of having window during prehospital transport. Therefore, the question
fibrinogen <1.6g/L, P=.02, OR = 6.9 (1.3–36.1). Conclusion: of how to identify patients who might benefit from early fi-
In major trauma patients transported by helicopter EMS, per- brinogen replacement remains unanswered to date.
sistent hypotension after the first blood transfusion and an ini-
tial EDSI ≥1.5 were both associated with low fibrinogen levels. Prehospital code red criteria (CRC) is a clinical indicator term
coined in the UK and defined as systolic blood pressure (SBP)
<90mmHg despite a small fluid bolus in suspected or con-
Keywords: fibrinogen; air ambulances; emergency helicopters;
HEMS; trauma; prehospital; hemorrhage; emergency medical firmed massive hemorrhage. CRC is sensitive for predicting
services; transfusion need for transfusion, hemorrhagic death, and can optimize re-
ceiving hospital preparation. Our health records review will
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seek to identify prehospital variables, such as CRC, that best
predict which trauma patients develop hypofibrinogenemia.
*Correspondence to domhnall13@hotmail.com
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1 Dr. Shannon Pretty, Aliyah Gauri, and Dr. Leandro Solis Aguilar are affiliated with the Department of Emergency Medicine, University of Al-
berta, Edmonton, Alberta, Canada. Domhnall O’Dochartaigh, Julie Zwicker, Elfriede Cross, and Matthew Douma are affiliated with Alberta
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Health Services, Emergency, Edmonton Alberta, Canada. Domhnall O’Dochartaigh and Dr. Eddie Chang are affiliated with Shock Trauma
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Air Rescue Service (STARS), Alberta, Canada. Dr. Efrem Violato, Dr. Pete Chen, and Dr. Xenia Cravetchi are affiliated with the Faculty of
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Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada. Dr. Sandy Widder, Dr. Arabesque Parker, and Matthew Douma
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are affiliated with the Department of Critical Care, University of Alberta, Edmonton, Alberta, Canada. Dr. Sandy Widder is affiliated with the
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Department of Surgery, University of Alberta, Edmonton, Alberta, Canada. Dr. Arabesque Parker is affiliated with the Department of Medicine,
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Division of Hematology, University of Alberta, Alberta, Canada. Matthew Douma is affiliated with Midwifery and Health Systems, University
College Dublin, Dublin, Ireland.
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