Pleural effusions following cardiac surgery: prevalence, risk factors, and clinical features.

<bold>Background: </bold>Pleural effusion is a common complication of cardiac surgery, but its characteristics and predisposing factors should be documented further. Our objective was to determine the prevalence, characteristics, and determinants of clinically significant pleural effusions, defined as those requiring therapeutic pleural drainage according to clinical assessment.<bold>Methods: </bold>The prevalence and characteristics of patients who had a pleural effusion within 30 days of undergoing coronary artery bypass graft, valve replacement, or both were analyzed retrospectively at our institution over a 2-year period.<bold>Results: </bold>Among the 2,892 patients included in the study (mean age, 66 years; men, 2,139), 192 patients (6.6%) had experienced a clinically significant pleural effusion in the 30 days postsurgery. These effusions occurred after a mean (+/- SD) duration of 6.6 +/- 5.9 days following interventions. Pleural fluid analysis was obtained in 114 patients (59.4%); all met the criteria for an exudate. Pleural fluid was hemorrhagic in 50% of cases. Age, body weight, baseline pulmonary function, and smoking status were similar between patients with and without effusion; however, the proportion of women; the number of patients with previous conditions of heart failure, atrial fibrillation, or peripheral vascular disease; and the number of patients receiving therapy with an anticoagulant or antiarrhythmic agent was higher in the pleural effusion group. Patients with pleural effusion had an increased prevalence of postoperative complications.<bold>Conclusions: </bold>Pleural effusion is a common complication of heart surgery, is associated with other postoperative complications, and is more frequent in women and in patients with associated cardiac or vascular comorbidities and medications used to treat those conditions.<bold>Trial Registration: </bold>ClinicalTrials.gov Identifier: NCT00665015. [ABSTRACT FROM AUTHOR]