What is the outcome of intraoperative management? Reply

Editor, We thank Professor G. Drummond for the interest he devoted to our study [1]. We agree with him that improving postoperative outcome and accelerating postoperative rehabilitation are major challenges that anaesthesiologists must take up during the next years. It is true that most published studies on ventilatory management during anaesthesia focus on surrogates of pulmonary function whose clinical significance regarding morbidity, mortality and length of hospital stay remains unknown. We would like to emphasize that some intraoperative ventilatory settings, however, result in proven benefit on postoperative outcome. Use of high-inspired oxygen fraction that increases tissue oxygen tension reduces the incidence of wound infections [2,3]. Therefore, other strategies that increase tissue oxygen tension are expected to produce similar benefit. This needs, however, to be demonstrated. Ventilation with low tidal volume decreases the duration of postoperative ventilation and the risk of postoperative pulmonary failure after one-lung ventilation [4,5]. Nevertheless, evidences that similar reduction in tidal volume also improves respiratory outcome after routine general anaesthesia are currently lacking. Data that are briefly summarized in our review, however, favour intraoperative use of small tidal volumes and positive end-expiratory pressure (PEEP) during general anaesthesia [1]. We agree that these studies use surrogates of pulmonary function and integrity such as alveolar inflammation and coagulation. The intensive care literature, however, demonstrates that ventilation with low tidal volume and PEEP reduces the risk of subsequent ventilatory failure and improves outcome of patients with acute respiratory distress syndrome [6–8]. Together, these data make ventilation with low tidal volume and PEEP one potential way to improve postoperative outcome in patients and after surgical procedures at risk of postoperative pulmonary complications. These clinically important hypotheses need to be tested in large prospective randomized controlled trials.