Characteristics of Nontrauma Patients Receiving Prehospital Blood Transfusion with the Same Triggers as Trauma Patients: A Retrospective Observational Cohort Study

Objective: While prehospital blood transfusion (PHBT) for trauma patients has been established in many services, the literature on PHBT use for nontrauma patients is limited. We aimed to describe and compare nontrauma and trauma patients receiving PHBT who had similar hemodynamic triggers. Methods: We analyzed 3.5 years of registry data from a single prehospital critical care unit. The PHBT protocol included two packed red blood cell units and was later completed with two freeze-dried plasma units. The transfusion triggers were a strong clinical suspicion of massive hemorrhage and systolic blood pressure below 90 mmHg or absent radial pulse. Results: Thirty-six nontrauma patients and 96 trauma patients received PHBT. The nontrauma group had elderly patients (median 65 [interquartile range, IQR, 56-73] vs 37 [IQR 25-57] years, p < 0.0001) and included patients with gastrointestinal bleeding (n = 15; 42%), vascular catastrophes (n = 9; 25%), postoperative bleeding (n = 6; 17%), obstetrical bleeding (n = 4; 11%) and other (n = 2; 6%). Cardiac arrest occurred in nine (25%) nontrauma and in 15 (16%) trauma patients. Of these, 5 (56%) and 10 (67%) survived to hospital admission and 3 (33%) and 2 (13%) to hospital discharge. On admission, the nontrauma patients had lower hemoglobin (median 95 [84-119] vs 124 [108-133], p < 0.0001), higher pH (median 7.40 [7.27-7.44] vs 7.30 [7.19-7.36], p = 0.0015) and lower plasma thromboplastin time (median 55 [45-81] vs 72 [58-86], p = 0.0261) than the trauma patients. Conclusions: We identified four nontrauma patient groups in need of PHBT, and the patients appeared to be seriously ill. Efficacy of prehospital transfusion in nontrauma patients should be evaluated futher in becoming studies.