Postoperative ventilation: a goal-directed approach?

Abstract

After every operation, the anaesthetist makes a decision as to whether his/ber patient requires or would benefit from mechanical ventilatory support. In high-risk patients, this decision is considered preoperatively; however, intraoperative events can mandate a re-assessment of the need for postoperative ventilation. The assumption is often made that ventilation can prevent postoperative respiratory complications. Yet, there is no evidence that temporary ventilatory support, as a routine measure, prevents atelectasis or pneumonia. In fact, some reviewers suggest that the opposite may be true. The decision to provide postoperative ventilation often initiates the admission to an intensive care unit (ICU) with comprehensive monitoring and nursing care. This decision, therefore, initiates the use of other technologies and resources. Routine postoperative ventilation can resuit in the use of ICU care by default, based on convenience rather than physiological need. As many as 30% of surgical ICU admissions 2,3 require monitoring only with no life-threatening events. Large discrepancies in the use of ICU interventions for similar postoperative patients suggests that a re-evahiation of critical care utilization is required.4 No one questions that there are benefits of postoperative positive pressure ventilation (PPV) for appropriately selected patients. However, the risks and benefits are yet to be determined. 5,6 The challenge is to select appropriate patients and to tailor the intraoperative management to the anticipated postoperative needs. This review will focus on indications for postoperative ventilation based on physiological principles .and current understanding of postoperative respiratory physiology. Based on a thorough preoperative assessment and an understanding of intraoperative and anticipated postoperative changes in cardiopulmonary function, the clinician's goals should focus on correcting reversible components of postoperative respiratory dysfunction. Weaning and extubation follow.