Outcomes of Protocol-Driven Care of Critically Ill Severely Anemic Patients for Whom Blood Transfusion Is Not an Option

Abstract

Objective: To compare the outcomes of severely anemic critically ill patients for whom transfusion is not an option ("bloodless" patients) with transfused patients.

Design: Cohort study with propensity score matching.

Setting: ICU of a referral center.

Patients: One hundred seventy-eight bloodless and 441 transfused consecutive severely anemic, critically ill patients, admitted between May 1996 and April 2011, and having at least one hemoglobin level less than or equal to 8 g/dL within 24 hours of ICU admission. Patients with diagnosis of brain injury, acute myocardial infarction, or status postcardiac surgery were excluded.

Interventions: Allogeneic RBC transfusion during ICU stay.

Measurements and main results: Primary outcome was in-hospital mortality. Other outcomes were ICU mortality, readmission to ICU, new electrocardiographic or cardiac enzyme changes suggestive of cardiac ischemia or injury, and new positive blood culture result. Transfused patients were older, had higher hemoglobin level at admission, and had higher Acute Physiology and Chronic Health Evaluation II score. Hospital mortality rates were 24.7% in bloodless and 24.5% in transfused patients (odds ratio, 1.01; 95% CI, 0.68-1.52; p = 0.95). Adjusted odds ratio of hospital mortality was 1.52 (95% CI, 0.95-2.43; p = 0.08). No significant difference in ICU readmission or positive blood culture results was observed. Analysis of propensity score-matched cohorts provided similar results.

Conclusions: Overall risk of mortality in severely anemic critically ill bloodless patients appeared to be comparable with transfused patients, albeit the latter group had older age and higher Acute Physiology and Chronic Health Evaluation II score. Use of a protocol to manage anemia in these patients in a center with established patient blood management and bloodless medicine and surgery programs is feasible and likely to contribute to improved outcome, whereas more studies are needed to better delineate the impact of such programs.