Risk factors associated with surgical reintervention in postoperative cardiac surgery: is there an impact of intraoperative fluid balance?

Abstract

Introduction: The relationship between intraoperative fluid balance and surgical reintervention in patients undergoing cardiac surgery is currently unclear. Methods: Case‒control study nested in a historical cohort. Patients over 18 years of age in the immediate postoperative period of cardiac surgery were included, and unplanned surgical reintervention was evaluated as the primary outcome. Four groups were created according to intraoperative fluid balance. We performed a univariate analysis comparing patients who underwent reintervention (cases) with those who did not (controls), and a multivariate conditional logistic regression model controlling for multiple confusion variables. Results: In total, 304 patients were analyzed (76 cases and 228 controls). The median age was 67 years, and the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II was greater in cases than in controls (2.05 (1.21–3.48) vs. 2.5 (1.46–4.63), p = 0.016). A greater proportion of smokers were found in cases (36.8% vs. 15.3%, p < 0.01). No differences were found in fluid balance between groups. Moreover, no differences were found according to the type of procedure performed given the match. The total duration of surgery was longer in reintervened patients (median 4 h (interquartile range (IQR) 3.66–5) vs. 5 h (IQR 4–5.11), p = 0.04). According to multivariate analysis, no association was found between fluid balance and the risk of requiring reintervention (odds ratio (OR) 1.03, confidence interval (CI) 0.86–1.23, p = 0.75). However, reintervention was associated with smoking (OR 4.44; CI 2.09–9.44; p < 0.01) and total duration of the surgical procedure (OR 1.39; CI 1.06–1.82; p < 0.01). The type of programming (urgent surgery) (OR 0.34; CI 0.16–0.74; p < 0.01) and history of acute myocardial infarction in the last 7 days (OR 0.46; CI 0.21–0.99; p = 0.04) were more frequent in patients who did not undergo reintervention. Conclusion: Our findings did not reveal an association between a positive intraoperative fluid balance and the incidence of unplanned reintervention after cardiac surgery.