Impact of anemia on short-term survival in severe COPD exacerbations: a cohort study

Purpose: Anemia is reported to be an independent predictor of hospitalizations and survival in COPD. However, little is known of its impact on short-term survival during severe COPD exacerbations. The primary objective of this study was to determine whether the presence of anemia increases the risk of death in acute respiratory failure due to severe COPD exacerbations. Patients and methods: Consecutive patients with COPD exacerbation who were admitted to the intensive care unit with the diagnosis of acute respiratory failure and required either invasive or noninvasive ventilation (NIV) were analyzed. Results: A total of 106 patients (78.3% male; median age 71 years) were included in the study; of them 22 (20.8%) needed invasive ventilation immediately and 84 (79.2%) were treated with NIV. NIV failure was observed in 38 patients. Anemia was present in 50% of patients, and 39 patients (36.8%) died during hospital stay. When compared to nonanemic patients, hospital mortality was significantly higher in the anemic group (20.8% vs 52.8%, respectively; P=0.001). Stepwise multivariate logistic regression analysis showed that presence of anemia and NIV failure were independent predictors of hospital mortality with odds ratios (95% confidence interval) of 3.99 ([1.39-11.40]; P=0.010) and 2.56 ([1.60-4.09]; P<0.001), respectively. Anemia was not associated with long-term survival in this cohort. Conclusion: Anemia may be a risk factor for hospital death in severe COPD exacerbations requiring mechanical ventilatory support.