Page 63 - JSOM Summer 2024

Incidence of Coagulopathy After Resuscitation
at a Role 1 Facility

The Prehospital Trauma Registry Experience

Brannon L. Inman, MD ; Brit J. Long, MD ; Michael D. April, MD, DPhil, MSc ;
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Andrew D. Fisher, MD, MPAS ; Julie A. Rizzo, MD ; Steven G. Schauer, DO, MS *
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ABSTRACT
Background: The development of acute traumatic coagulop- Syria. However, substantial investment was needed for early
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athy is associated with increased mortality and morbidity in and aggressive mitigation and treatment. Casualties with se-
patients with battlefield traumatic injuries. Currently, the in- vere wounds and hemorrhage are at risk for both intrinsic
cidence of acute traumatic coagulopathy in the Role 1 setting and extrinsic insults. Acute traumatic coagulopathy (ATC)
is unclear. Methods: We queried the Prehospital Trauma Reg- is a multifactorial complication that is associated with poor
istry (PHTR) module of the Department of Defense Trauma outcomes. 7–11 ATC is the result of an intrinsic mechanism of
Registry (DoDTR) for all encounters from inception through hemorrhagic shock and a marker of injury severity. It is an
May 2019. The PHTR captures data on Role 1 prehospital independent risk factor for mortality, with an increased odds
care. Data from the PHTR was linked to the DoDTR to an- of death approaching 322%. 8,12 The risk of developing ATC is
alyze laboratory data and patient outcomes using descriptive proportional to injury severity, with injury severity scores (ISS)
statistics. We defined coagulopathy as an international normal- greater than 25 strongly associated with ATC. 8,9
ized ratio (INR) of ≥1.5 or platelet count ≤150×10 /L. Results:
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A total of 595 patients met the inclusion criteria; 36% (212) Shock and hyperfibrinolysis as well as endothelial dysfunction
met our definition for coagulopathy, with 31% (185) carrying are thought to be fundamental drivers of ATC. 1,7,13 Tissue hypo-
low platelet numbers, 11% (68) showing an elevated INR, and perfusion impairs the thrombomodulin–protein C pathway,
7% (41) with both. The baseline (no coagulopathy) cohort had which may be a significant driver of ATC, even in the absence
a mean INR of 1.10 (95% CI 1.09–1.12) versus 1.38 (95% of coagulation factors. Protein C, or coagulation factor XIV,
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CI 1.33–1.43) in the coagulopathic cohort. The mean platelet plays a key role in regulating anticoagulation via inactivation
count was 218 (95% CI 213–223) ×10 /L in the baseline co- of protein factors V and VIII. However, recent data question
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hort versus 117 (95% CI 110–125) ×10 /L in the coagulopathic the role of protein C in ATC. 14,15 The development of acidosis
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cohort. Conclusions: Our findings indicate a high incidence of in the setting of shock further exacerbates coagulopathy, with
coagulopathy in trauma patients. Approximately one-third of notable impairment of coagulation cascade at pH <7.15. 16–18
wounded patients had laboratory evidence of coagulopathy The degree of coagulopathy secondary to acidosis is similar to
upon presentation to a forward medical care facility. Advanced that observed in hypothermia. 18,19 Further, hypocalcemia may
diagnostic facilities are therefore needed to facilitate early diag- result from traumatic injury or subsequent to blood products
nosis of acute traumatic coagulopathy. Blood products with a administered during resuscitation, which may result in wors-
long shelf life can aid in early correction. ening ATC. 11,20,21 Nonetheless, the clinical impact of incidental
hypocalcemia in hemorrhagic shock prior to blood transfusion
Keywords: prehospital; trauma; coagulopathy; coagulation; is unknown. 22
military
The international normalized ratio (INR) is a measure of the
ratio of prothrombin time to activated partial thromboplastin
time. Both of these parameters reflect the intrinsic pathways
Introduction
of the coagulation cascade, especially in the setting of trauma,
Rapid aeromedical evacuation, advances in personal protec- which is most commonly affected by the loss of coagulation
tive equipment, and prehospital care contributed to unprece- factors found in plasma. Coagulation is generally impaired at
dented survival during the conflicts in Afghanistan, Iraq, and an INR threshold of ≥1.5. 23–25 Platelets are the primary blood
*Correspondence to steven.g.schauer.mil@army.mil
1 Capt Brannon L. Inman is an emergency medicine physician affiliated with Brooke Army Medical Center, JBSA – Fort Sam Houston, San Anto-
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nio, TX. Maj Brit J. Long is an Associate Professor in the Department of Military and Emergency Medicine at the Uniformed Services University
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of the Health Sciences, Bethesda, MD, and an associate professor at Brooke Army Medical Center, San Antonio, Texas. LTC Michael D. April
is an Associate Professor in the Department of Military and Emergency Medicine at the Uniformed Services University of the Health Sciences,
Bethesda, MD, and is associated with the Center for Combat and Battlefield (COMBAT) Research at the University of Colorado School of
Medicine, Aurora, CO. MAJ (P) Andrew D. Fisher is currently a general surgery resident at the University of New Mexico School of Medicine,
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Albuquerque, NM and serving in the Texas Army National Guard. LTC Julie Rizzo is a neurosurgeon in the Department of Neurosurgery Walter
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Reed National Military Medical Center, Bethesda, MD. LTC Steven G. Schauer is an Associate Professor within the Department of Military and
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Emergency Medicine at the Uniformed Services University of the Health Sciences, Bethesda Maryland, is an emergency medicine physician and
fellow in anesthesia critical care medicine with Departments of Anesthesiology and Emergency Medicine at the University of Colorado School
of Medicine, and research fellow with the Center for Combat and Battlefield Research (COMBAT) at the University of Colorado School of
Medicine.
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