Preoperative maximal expiratory pressure is associated with duration of invasive mechanical ventilation after cardiac surgery: An observational study

To evaluate the association of maximal expiratory pressure (MEP), maximal inspiratory pressure (MIP), and peak expiratory flow (PEF) with total duration of invasive mechanical ventilation (IMV) in subjects undergoing cardiac surgery.Prolonged IMV is associated with respiratory infections, prolonged hospitalization, and increased mortality. Pulmonary function tests can help predict postoperative outcomes after cardiac surgery.We recruited subjects admitted for cardiac surgery. All MIP, MEP, and PEF measurements were performed before surgery. Multivariable analysis was performed using a multiple linear regression model to control for possible confounders and test for association of MIP, MEP, and PEF with IMV duration.Overall, 125 subjects were included in the study. Higher MEP was associated with reduced duration of IMV after adjustment for confounders (P = 0.015), but no such association was observed between MIP or PEF and IMV.In subjects undergoing elective cardiac surgery, preoperative MEP is associated with IMV duration.