DETERMINANTS OF PROLONGED MECHANICAL VENTILATION AFTER CORONARY-ARTERY BYPASS-GRAFTING

Background. Early extubation of cardiac surgical patients enhances amb ulation, improves cardiopulmonary function, and can lead to savings in health care costs. Methods. We retrospectively examined the role of 4 8 variables in determining the period of ventilatory support in 507 pa tients having coronary artery bypass grafting. Results. Fifteen (<3%) of 507 patients required ventilatory support in excess of 24 hours. am ong the remaining patients, extubation was achieved early (less than o r equal to 8 hours) (mean time, 5.65 +/- 1.31 hours) in 53% and late ( >8 hours) (mean time, 13.7 +/- 3.4 hours) in 47%. Logistic and linear multivariate regression analyses implicated increased age, New York He art Association functional class IV, intraoperative fluid retention, p ostoperative intraaortic balloon pump requirement, and bank blood tran sfusions as predictors of late extubation. Also, the linear regression linked lower body weight and number of anastomoses (or grafts) to inc reased mechanical ventilatory support. Conclusions. Analysis of the fl uid balance and cardiopulmonary bypass data suggests that earlier extu bation may be achieved by actively reducing fluid retention (eg, by he moconcentration) and time on bypass (eg, normothermia). Finally, inten sive care unit stay and postoperative length of stay were significantl y lower in the early versus late extubation groups without an increase in pulmonary complications.