Impact of Anemia in Critically Ill Burned Casualties Evacuated From Combat Theater via US Military Critical Care Air Transport Teams.

Background: US military Critical Care Air Transport Teams (CCATT) transport critically ill burn patients out of theater. Blood transfusion may incur adverse effects, and studies report lower hemoglobin (Hgb) value may be safe for critically ill patients. There are no studies evaluating the optimal Hgb value for critically ill burn patients prior to CCATT evacuation.

Objective: The aim of the study was to determine if critically ill burn casualties with an Hgb of 10 g/dL or less, transported via CCATT, have similar clinical outcomes at 30 days as compared with patients with an Hgb of greater than 10 g/dL.

Methods: We conducted an institutional review board-approved retrospective cohort study involving patients transported via CCATT. We separated our study population into two cohorts based on Hgb levels at the time of theater evacuation: Hgb ≤10 g/dL or Hgb ≥10 g/dL. We compared demographics, injury description, physiologic parameters, and clinical outcomes.

Results: Of the 140 subjects enrolled, 29 were Hgb ≤10, and 111 were Hgb ≥10. Both groups were similar in age and percent total body surface area burned. Those Hgb ≤10 had a higher injury severity score (34 ± 19.8 vs. 25 ± 16.9, P = 0.02) and were more likely to have additional trauma (50% vs. 25%, P = 0.04). Modeling revealed no persistent differences in mortality, and other clinical outcomes measured.

Conclusions: Critical Care Air Transport Teams transport of critically ill burn patients with an Hgb of 10 g/dL or less had no significant differences in complications or mortality as compared with patients with an Hgb of greater than 10 g/dL. In this study, lower hemoglobin levels did not confer greater risk for worse outcomes.