Early Extubation Versus Prophylatic Ventilation in the High Risk Patient

Abstract

To evaluate whether prophylactic ventilation during the early postoperative period diminishes pulmonary complications, 35 high risk, elderly patients undergoing major, elective abdominal aortic reconstruction were prospectively randomized into either an early extubation group or a prophylactic ventilation group. The 17 patients assigned to the prophylactic ventilation group received mechanical ventilation by assist/control mode until 8 a.m. of the first postoperative day. The 17 patients assigned to the early extubation group were extubated after the operation as soon as they could maintain a pH of 7.35, with a spontaneous respiratory rate of less than 30. Preoperative measurements of functional residual capacity, intrapulmonary shunt, and oxygen delivery were compared to similar measurements during the initial two postoperative days. There were no significant differences between the groups with respect to age, length of operation, duration of anesthesia, operative blood loss, intraoperative fluid administration, or number of intraoperative transfusions. Patients in the prophylactic ventilation group were ventilated for an average of 18.3 +/- 0.5 hours. Patients in the early extubation group were ventilated for an average of 3.3 +/- 0.5 hours (p < 0.0005). No patient in either group required reintubation. Intrapulmonary shunt and oxygen delivery were not significantly different between the groups at any time during the study period. There was no mortality or significant morbidity in either group. These findings suggest that in high risk surgical patients, prophylactic ventilation, per se, may not diminish respiratory complications or improve gas exchange.