Postoperative pulmonary function in coronary artery bypass graft surgery patients undergoing early tracheal extubation: a comparison between short-term mechanical ventilation and early extubation.

OBJECTIVE: To evaluate the effect of a short period of mechanical ventilation (3 hours) versus immediate extubation (within 1 hour of surgery) on pulmonary function, gas exchange, and pulmonary complications after coronary artery bypass graft (CABG) surgery.

DESIGN: Prospective randomized study.

SETTING: University teaching hospital.

PARTICIPANTS: Thirty-five patients undergoing CABG surgery.

INTERVENTIONS: Patients were randomized into 2 groups. Patients in group I were extubated as soon as possible after surgery. Patients in group II were ventilated for a minimum of 3 hours after surgery. Patients in both groups were extubated only after achieving predetermined extubation criteria. Patients who did not meet the criteria for extubation within the predetermined set time limit (90 minutes in group I and 6 hours in group II) were withdrawn from the study. Pulmonary function tests (vital capacity, forced expiratory volume in 1 second, total lung capacity, functional residual capacity), arterial blood gases, and chest radiographs were done preoperatively and postoperatively. Pulmonary complications were recorded.

MEASUREMENTS AND MAIN RESULTS: Demographic data were similar between groups. The mean time to extubation in group I was 45.7 plus minus 27.6 minutes and in group II was 201.4 plus minus 21 minutes (p < 0.01). Two patients in group I and 1 patient in group II did not meet the extubation criteria within the predetermined set time limit and were excluded from the study. In both groups, there was a significant decline in pulmonary function but no differences between groups at 24 or 72 hours after surgery. There were no differences between groups in blood gases, atelectasis scores, or pulmonary complications.

CONCLUSION: The data suggest that extending mechanical ventilation after CABG surgery does not affect pulmonary function. Provided that routine extubation criteria are met, patients can be safely extubated early (within 1 hour) after major cardiac surgery without concerns of further pulmonary derangement.