Clinical predictors of and mortality in acute respiratory distress syndrome: Potential role of red cell transfusion

Objective: Clinical predictors for acute respiratory distress syndrome (ARDS) have been studied in few prospective studies. Although transfusions are common in the intensive care unit, the role of submassive transfusion in non-trauma-related ARDS has not been studied. We describe here the clinical predictors of ARDS risk and mortality including the role of red cell transfusion. Design: Observational prospective cohort. Setting. Intensive care unit of Massachusetts General Hospital. Patients: We studied 688 patients with sepsis, trauma, aspiration, and hypertransfusion. Interventions: None. Measurements and Main Results: Two hundred twenty-one (32%) subjects developed ARDS with a 60-day mortality rate of 46%. Significant predictors for ARDS on multivariate analyses included trauma (adjusted odds ratio [ORadj] 0.22, 95% confidence interval [CI] 0.09-0.53), diabetes (ORadj 0.58, 95% Cl 0.36-0.92), direct pulmonary injury (ORadj 3.78, 95% CI 2.45-5.81), hematologic failure (ORadj 1.84, 95% CI 1.05-3.21), transfer from another hospital (ORadj 2.08, 95% CI 1.33-3.25), respiratory rate > 33 breaths/min (ORadj 2.39, 95% CI 1.51-3.78), hematocrit > 37.5% (ORadi 1.77, 95% CI 1.14-2.77), arterial pH < 7.33 (ORadj 2.00, 95% CI 1.31-3.05), and albumin <= 2.3 g/dL (ORadj 1.80, 95% CI 1.18-2.73). Packed red blood cell transfusion was associated with ARDS (ORadj 1.52, 95% CI 1.00-2.31, p =.05). Significant predictors for mortality in ARDS included age (ORadj 1.96, 95% CI 1.50-2.53), Acute Physiology and Chronic Health Evaluation III score (ORadj 1.78, 95% CI 1.16-2.73), trauma (ORadj 0.075, 95% CI 0.006-0.96), corticosteroids before ARDS (ORadj 4.65, 95% CI 1.47-14.7), and arterial pH < 7.22 (ORadj 2.32, 95% CI 1.02-5.25). Packed red blood cell transfusions were associated with increased mortality in ARDS (ORadj 1.10 per unit transfused; 95% CI 1.04-1.17) with a significant dose-dependent response (p = .02). Conclusions: Important predictors for the development of and mortality in ARDS were identified. Packed red blood cell transfusion was associated with an increased development of and increased mortality in ARDS.