Correlation between Surgical Risk Scales with Respiratory Muscle Strength and Functional Independence in Patients Submitted to Coronary Artery Bypass Grafting

Abstract

Background: The European Heart Surgery Risk Assessment System (EuroSCORE) and InsCor have been used to predict complications of cardiac surgery. However, their application to predict lung function and functionality is still uncertain. Objective: To correlate surgical risk scales with functional independence and pulmonary function in patients undergoing coronary artery bypass grafting. Methods: This was a prospective cohort study. In the preoperative period, the two surgical scales were applied, the maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and peak expiratory flow (PEF) were measured, and functionality was assessed using the functional independence measure (FIM). On the seventh postoperative day, the pulmonary function and functionality variables were reevaluated, compared with the preoperative values (delta) and correlated with the risk scales. Correlations of pulmonary function, functional independence and muscle strength variables with the surgical scales were made by Pearson correlation test. The significance level adopted was 5%. Results: Thirty-one patients were studied; most were male (77%), with a mean age of 56±8 years. Mean EuroSCORE was 2.3±0.5 and mean InsCOR was 1.2±0.5. MIP, MEP, and PEF reduced 30% (p<0.001), 33% (p<0.001) and 10% (p=0.23), respectively. The EuroSCORE correlated with MIP (r-0.78; p = 0.02) and FIM (r-0.79; p <0.01), and the InsCor correlated with MIP (r-0.77), MEP (r-0.73) and MIF (r-0.89; p=0.02). Conclusion: The EuroSCORE showed a strong negative correlation with MIP and FIM, while InsCor had a strong negative correlation with MIP, MEP and FIM.