Prehospital transfusion requirements in severe trauma: A multicenter, retrospective estimate of requirements

To estimate the proportion of severely injured trauma patients who would have met criteria for prehospital blood transfusion, assuming a benefit when prehospital management exceeds 20 min, by applying the ABC score to a multicenter French prehospital cohort.

We performed a retrospective observational study across four prehospital services in the Paris region over one year. Among all trauma missions, we included patients transported to a major trauma center or undergoing resuscitation for traumatic cardiac arrest. Exclusions were age < 18, burned patients, and interhospital transfers. We retrospectively calculated the ABC (Assessment of Blood Consumption) score at 10-minute intervals during the intervention (until 20 min before hospital arrival). Patients were considered "eligible" if ABC ≥ 2 and total prehospital intervention duration > 20 min. Secondary endpoints included: proportion receiving tranexamic acid, time intervals, and prehospital deaths or arrests. Data were double-reviewed by two physicians, with adjudication by a third in case of discrepancy. Confidence intervals were computed using Wilson's method.

Of 5921 missions performed, 139 met inclusion criteria. Twenty-seven patients (19.7%, 95% CI: 13.7-26.8%) met both ABC ≥ 2 and intervention time > 20 min, thus qualifying for prehospital transfusion under our assumptions. Median time intervals (IQR) were: dispatch-to-scene 10 min [7-15.5], on-scene 57 min [47.5-71], transport 20 min [16-31.8], total intervention 79 min [68-104]. Eighteen of the eligible patients (67%) received tranexamic acid. Five experienced cardiac arrest prehospital, and three died before hospital arrival.

In this French prehospital cohort, nearly one in five severe trauma patients would have been eligible for prehospital transfusion under the assumed criteria. This suggests that prehospital blood administration should not remain a rarity but merits serious consideration in advanced trauma systems.