Prehospital Blood for Trauma Resuscitation Associated with Lower In-Hospital Mortality

Severance AC, Kutcher ME, Taghavi S, Dransfield T, et al. Number Needed to Treat Analysis for Ground Prehospital Blood in Hemorrhagic Shock. J Am Coll Surg. August 2026.

Early hemorrhage control remains the cornerstone of trauma resuscitation, yet traditional ground emergency medical services (EMS) resuscitation relies predominantly on crystalloid fluids. Severance and colleagues compared outcomes after prehospital crystalloid, packed red blood cells (pRBC), and whole blood (WB) resuscitation and quantified absolute risk reduction (ARR) and number needed to treat (NNT) for survival.

The study evaluated trauma patients with hemorrhagic shock (evidence of hemorrhage and shock index >1.0) who were enrolled in a prospective multicenter ground EMS registry and received crystalloid alone, pRBC, or WB during transport. The primary outcome was in-hospital mortality. Secondary outcomes included change in shock index from the prehospital setting to emergency department arrival. ARR and NNT were calculated with 95% confidence intervals.

Among 299 patients, mortality was highest after crystalloid resuscitation (13/84, 15.5%) compared with pRBC (9/168, 5.4%) and WB (2/47, 4.3%). Shock index improved in all groups, with the greatest reduction after pRBC (Δ−0.32 vs crystalloid Δ−0.14; p<0.001).

Compared with crystalloid, ARR was 10.1% (95% CI, 2.5–19.7%) for pRBC (NNT≈10; p=0.02), 11.2% (95% CI, 1.5–20.9%) for WB (NNT≈9; p=0.03), and 10.4% (95% CI, 2.7–18.0%) for combined blood products (NNT≈10; p=0.006). Contextual comparison demonstrated favorable NNT estimates relative to established trauma interventions.

These findings support implementation research and systems-level evaluation of ground EMS prehospital blood programs for hemorrhagic shock.