The impact of blood transfusion on morbidity and mortality after cardiac surgery.

OBJECTIVES

To analyze the impact of blood transfusion on the incidence of clinical outcomes postoperatively (PO) from cardiac surgery.

METHODS

Retrospective cohort study. We analyzed 4028 patients undergoing coronary artery bypass grafting (CABG), valve (TV), or both, in Brazilian tertiary university hospital between 1996 and 2009. We compared the postoperative complications between patients with blood transfusion (n = 916) and non-blood transfusion (n = 3112). Univariate analysis was performed using the Student t test, and multivariate logistic regression bivariate (stepwise forward). Were considered significant variables with P <0.05.

RESULTS

Patients who received blood transfusions had more infectious episodes as mediastinitis (4.9% vs. 2.2%, P <0.001), respiratory infection (27.8% vs 17.1%, P <0.001) and sepsis (6.2% vs. 2.5%, P <0.001). There were more episodes of atrial fibrillation (AF) (27% vs. 20.4%, P <0.001), acute renal failure (ARF) (14.5% vs 7.3%, P <0.001) and stroke (4.8% vs. 2.6%, P = 0.001). The length of PO hospital stay was higher in transfused (13 ± 12.07 days vs. 9.72 ± 7.66 days, P <0.001). However, mortality didn't differ between groups (10.9% vs. 9.1%, P = 0.112). The transfusion was shown to be a risk factor for: respiratory infection (OR: 1.91, 95% CI 1.59-2.29, P <0.001), AF (OR: 1.35, 95% CI 1.13-1.61, P = 0.01), sepsis (OR: 2.08, 95% CI 1.4-3.07, P <0.001), mediastinitis (OR: 2.14, 95% CI: 1.43-3.21, P <0.001), stroke (OR: 1.63, 95% CI 1.1-2.41, P = 0.014) and ARF (OR 1.8, 95% CI: 1.39-2.33, P <0.001).

CONCLUSION

The blood transfusion is associated with increased risk of infectious events, episodes of AF, ARF and stroke, as well as the increased length of hospital stay but not mortality.