Abstract
Hemorrhage remains the leading cause of preventable morality, resulting in the death of over a third of all trauma patients. Additionally, twenty-five percent of trauma patients present on admission with acute traumatic coagulopathy (ATC) which portends a mortality approaching fifty percent. ATC has been defined by multiple parameters including international normalized ratio (INR) >1.2, rotational thromboelastometry (ROTEM) clot amplitude at 5 minutes (CA5) ≤ 35 mm and lysis at 60 minutes (LI60) ≤ 85%. Damage control resuscitation (DCR), the practice of the Joint Theater Trauma System in Iraq and Afghanistan, is based on rapid hemorrhage control, permissive hypotension and transfusion of blood products in a ratio that aims to deliver the functionality of whole blood (1:1:1, red cells:plasma:platelets), in addition to limiting crystalloid resuscitation. ROTEM defined ATC has not been observed over time among DCR eligible combat casualties. The goal of this study was to identify ATC and the effects of DCR in trauma patients treated at level III trauma hospitals in Afghanistan.
In this prospective observational study, 88 trauma patients were treated at Craig Air Force Theatre Hospital – Bagram, or Kandahar NATO Hospital in the Afghanistan Theatre. We included only patients from coalition forces identified as having injury that would result in the loss of life or total disability resulting in activation of DCR. Blood was obtained for analysis upon admission and at 6 and 24 hours after admission by a designated research team. Blood was analyzed by ROTEM with multiple assays (EXTEM, FIBTEM, APTEM); however, data was not available to the treatment team. Complete blood counts and INR were also obtained and Injury Severity Scores (ISS) were determined. Transfusion requirements of red blood cells (RBCs), platelets (PLT), fresh frozen plasma (FFP) and cryoprecipitate were recorded for the first 24 hours following admission. ROTEM changes over time were analyzed using Wilcoxon signed-rank test.
Forty patients in the cohort had ROTEM (EXTEM) data obtained for evaluation as equipment was unavailable during a portion of the study. The median ISS was 21.5 (IQR 14-27). Four of the patients in the cohort died. The median admission hemoglobin and hematocrit were 11.1 g/dL (IQR 10.1-12) and 32.3% (IQR 29-34.5) respectively. The median INR was 1.3 (IQR 1.2-1.4). The median patient RBC to FFP to PLT ratio was 1:1:0.8. The median clot time (CT) and maximum clot firmness (MCF) were 58.5 sec (IQR 51-65.5) and 56 mm (IQR 51-60.5) respectively. Median CA5 was 37.5 mm (IQR 31-45). ATC as identified by CA5 ≤ 35 mm was present in 15 of 40 patients (38%) upon admission. The median CA5 of patients who met criteria for ATC on admission was 26 mm (IQR 15-34) which improved to 38 mm (IQR 33-44) at 24 hours (p < 0.01). Median LI45 was 98% (IQR 96-99). Hyperfibrinolysis as defined by LI45 ≤ 85% was observed in 4 of 40 patients (10%) upon admission which did not change significantly at 24 hours.
The incidence of acute traumatic coagulopathy as defined by ROTEM parameters in this high risk military cohort appears to be higher compared to that reported for civilian populations. These data suggest that current DCR practices including a 1:1:1 RBC:FFP:PLT ratio appropriately target high risk trauma patients with ATC and that this strategy appears to be associated with a reduction in the burden of coagulopathy by 24 hours.
No relevant conflicts of interest to declare.
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