Transfusion strategies and development of acute respiratory distress syndrome in combat casualty care.

BACKGROUND

Damage-control resuscitation (DCR) has been advocated to reduce mortality in military and civilian settings. However, DCR and excessive crystalloid resuscitation may be associated with a higher incidence of acute respiratory distress syndrome (ARDS). We sought to examine the impact of resuscitation strategies on ARDS development in combat casualty care.

METHODS

A retrospective review of Joint Theater Trauma Registry data on US combat casualties who received at least 1 U of blood product within the first 24 hours of care was performed, cross-referenced with the cohort receiving mechanical ventilation (n = 1,475). Massive transfusion (MT, ≥10 red blood cells [RBCs] and/or whole blood in 24 hours) and volume/ratios of plasma/RBC, platelet/RBC, and crystalloid/RBC (C/RBC, crystalloid liters/RBC units) were examined using bivariate/multivariate logistic regression and local regression analyses as ARDS risk factors, controlling for age, injury severity, admission systolic blood pressure, and Glasgow Coma Scale (GCS) score.

RESULTS

ARDS was identified in 95 cases (6.4%). MT was required in 550 (37.3%) of the analysis cohort. ARDS was more common in MT (46 of 550, 8.4%) versus no-MT cohort (49 of 925, 5.3%), but mortality was not different (17.4% MT vs. 16.3% no-MT). ARDS patients received significantly increased crystalloid of blood product volumes. Increased crystalloid resuscitation (C/RBC ratio > 1.5) occurred in 479 (32.7%) of 1,464 patients. Unadjusted mortality was significantly increased in the cohort with C/RBC ratio of 1.5 or less compared with those with greater than 1.5 (19.1% vs. 6.3%, p < 0.0001), but no difference in ARDS (6.5% vs. 6.6%) was identified. Platelet/RBC ratio did not impact on ARDS. Increasing plasma (odds ratio, 1.07; p = 0.0062) and crystalloid (odds ratio, 1.04; p = 0.041) volumes were confirmed as independent ARDS risk factors.

CONCLUSION

In modern combat casualty care, increased plasma and crystalloid infusion were identified as independent risk factors for ARDS. These findings support a practice of decreased plasma/crystalloid transfusion in trauma resuscitation once hemorrhage control is established to achieve the mortality benefit of DCR and ARDS prevention.