Determinants of Longer Duration of Endotracheal Intubation After Adult Cardiac Operations

Background. Poor pulmonary reserve is a risk factor that is used to exclude some patients from major operations. However, the value of routine spirometry in patients undergoing cardiac operations has not been widely evaluated. Methods. The outcomes of 586 consecutive adult patients undergoing cardiac operations were reviewed retrospectively to assess predictors of longer duration of endotracheal intubation. Results. By univariate analysis, congestive failure (p < 0.001), cardiomegaly (p = 0.002), recent myocardial infarction (p = 0.039), priority of operation (p = 0.005), previous cardiac operation (p < 0.001), and renal insufficiency (p = 0.002) increased the risk of longer endotracheal intubation. Spirometry (forced vital capacity, forced expiratory volume at 1 second, the ratio of forced expiratory volume at 1 second to forced vital capacity) did not correlate with longer endotracheal intubation. Perioperative complications, such as myocardial infarction (p < 0.001), coma, reexploration for bleeding, and reduced cardiac output (p < 0.001 each), correlated with longer duration of intubation. By multiple regression, priority of operation (p = 0.03), congestive failure (p = 0.02), and previous cardiac operation (p = 0.005) among preoperative risks and bleeding, reduced cardiac output, stroke, coma, and MB fraction of creatine kinase released postoperatively (p < 0.001 each) predicted longer duration of endotracheal intubation. Conclusions. Postoperative cardiac function and the occurrence of complications are more significant than preoperative pulmonary function in determining the duration of endotracheal intubation after cardiac operation. Routine spirometry is probably unnecessary for most adult cardiac patients.