Quantifying the benefit of whole blood on mortality in trauma patients requiring emergent laparotomy.

Background: Whole blood (WB) transfusions in trauma represent an increasingly utilized resuscitation strategy in trauma patients. Previous reports suggest a probable mortality benefit with incorporating WB into massive transfusion protocols. However, questions surrounding optimal WB practices persist. We sought to assess the association between the proportion of WB transfused during the initial resuscitative period and its impact on early mortality outcomes for traumatically injured patients.

Methods: We performed a retrospective analysis of severely injured patients requiring emergent laparotomy and ≥3 units of red blood cell containing products (WB or packed red blood cells) within the first hour from an ACS Level I Trauma Center (2019-2022). Patients were evaluated based on the proportion of WB they received compared with packed red blood cells during their initial resuscitation (high ratio cohort ≥50% WB vs. low ratio cohort <50% WB). Multilevel Bayesian regression analyses were performed to calculate the posterior probabilities and risk ratios (RR) associated with a WB predominant resuscitation for early mortality outcomes.

Results: Two hundred sixty-six patients were analyzed (81% male; mean age, 36 years; 61% penetrating injury; mean Injury Severity Score, 30). The mortality was 11% at 4 hours and 14% at 24 hours. The high ratio cohort demonstrated a 99% (RR, 0.12; 95% credible interval, 0.02-0.53) and 99% (RR, 0.22; 95% credible interval, 0.08-0.65) probability of decreased mortality at 4 hours and 24 hours, respectively, compared the low ratio cohort. There was a 94% and 88% probability of at least a 50% mortality relative risk reduction associated with the WB predominate strategy at 4 hours and 24 hours, respectively.

Conclusion: Preferential transfusion of WB during the initial resuscitation demonstrated a 99% probability of being superior to component predominant resuscitations with regards to 4-hour and 24-hour mortality suggesting that WB predominant resuscitations may be superior for improving early mortality. Prospective, randomized trials should be sought.

Level of evidence: Therapeutic/Care Management; Level IV.