Prehospital Fibrinogen Levels in Major Trauma Patients Transported by Helicopter Emergency Medical Service: Determining Who Might Benefit.

OBJECTIVES

Low fibrinogen contributes to poor outcomes in patients with traumatic coagulopathy. Empiric fibrinogen replacement is not supported. Early identification of patients at high risk of hypofibrinogenemia may enable targeted support. We sought to identify prehospital variables associated with hypofibrinogenemia at emergency department (ED) arrival.

METHODS

We retrospectively reviewed health records (January 2015 to August 2019) of consecutive patients transported by helicopter EMS to two trauma centers who received one or more units of packed red blood cells (pRBCs) during transport. The primary outcome was first ED fibrinogen level transformed into a binomial variable (<1.6g/L or ≥1.6g/L) for the 65 patients analyzed. Direct multivariable logistic regression examined the independent variables (hypotension, shock index (SI), and systolic blood pressure). Odds ratios and 95% CIs were reported.

RESULTS

Hypotension after first pRBC transfusion was significantly associated with low ED first fibrinogen level, P=.03, with 6.6 (1.1-40.15) times greater odds of fibrinogen <1.6g/L. Hypotension post-transfusion was also associated with ED first international normalized ratio (INR) >1.5, P=.013, with those cases having 17.5 (1.8-169.2) greater odds of INR >1.5. Additionally, an EDSI ≥1.5 had 8.9 (1.9-42.6) times greater odds of fibrinogen <1.6g/L than those with an EDSI <1, P=.006. Compared with the EDSI 1-1.49 group, those with an EDSI ≥1.5 had 6.9 times greater odds of having fibrinogen <1.6g/L, P=.02, OR=6.9 (1.3-36.1).

CONCLUSION

In major trauma patients transported by helicopter EMS, persistent hypotension after the first blood transfusion and an initial EDSI ≥1.5 were both associated with low fibrinogen levels.