Ann Surg. 2019;Epub ahead of print

# Prehospital Blood Product and Crystalloid Resuscitation in the Severely Injured Patient: A Secondary Analysis of the Prehospital Air Medical Plasma Trial.

Guyette F, Sperry J, Peitzman A, Billiar T, Daley B, Miller R, Harbrecht B, Claridge J, Putnam T, Duane T, Phelan H, Brown J

MINI: Hemorrhage is the primary cause of preventable trauma death. Secondary analyses of scene patients from the PAMPer trial demonstrated that prehospital packed red blood cell and plasma had the greatest reduction in 30-day mortality compared with crystalloid-only resuscitation. Patients with hemorrhagic shock should receive prehospital blood products when available, preferably packed red blood cell and plasma.

OBJECTIVE: The aim of this study was to determine whether prehospital blood products reduce 30-day mortality in patients at risk for hemorrhagic shock compared with crystalloid only resuscitation.

SUMMARY OF BACKGROUND DATA: Hemorrhage is the primary cause of preventable death after injury. Large volume crystalloid resuscitation can be deleterious. The benefits of prehospital packed red blood cells (PRBCs), plasma, or transfusion of both products among trauma patients is unknown compared with crystalloid.

METHODS: Secondary analysis of the multicenter PAMPer trial was performed on hypotensive injured patients from the scene. The trial randomized 27 helicopter bases to prehospital plasma or standard resuscitation. Standard resuscitation at the sites was equally divided between crystalloid and crystalloid + PRBC. This led to 4 prehospital resuscitation groups: crystalloid only; PRBC; plasma; and PRBC+plasma. Cox regression determined the association between resuscitation groups and risk-adjusted 30-day mortality. The dose effect of resuscitation fluids was also explored.

RESULTS: Four hundred seven patients were included. PRBC+plasma had the greatest benefit [hazard ratio (HR) 0.38; 95% confidence interval (95% CI) 0.26-0.55, P < 0.001], followed by plasma (HR 0.57; 95% CI 0.36-0.91, P = 0.017) and PRBC (HR 0.68; 95% CI 0.49-0.95, P = 0.025) versus crystalloid only. Mortality was lower per-unit of PRBC (HR 0.69; 95% CI 0.52-0.92, p = 0.009) and plasma (HR 0.68; 95% CI 0.54-0.88, P = 0.003). Crystalloid volume was associated with increasedmortality among patients receiving blood products (HR 1.65; 95% CI 1.17-2.32, P = 0.004).

CONCLUSION: Patients receiving prehospital PRBC+plasma had the greatest mortality benefit. Crystalloid only had the worst survival. Patients with hemorrhagic shock should receive prehospital blood products when available, preferably PRBC+plasma. Prehospital whole blood may be ideal in this population.