Open lung approach versus conventional protective ventilation in obese patients undergoing open abdominal surgery: a randomized controlled trial

Purpose Open abdominal surgeries are associated with an increased risk of postoperative pulmonary complications, especially in obese patients, which seem to be related directly to intraoperative mechanical ventilation. The present study aimed to compare the effect of using conventional protective ventilation (CPV) [low tidal volume and fixed positive end expiratory pressure (PEEP)] with open lung approach (OLA) (recruitment maneuver followed by personalized PEEP) on postoperative pulmonary complications. Patients and methods A total of 56 obese patients undergoing open abdominal surgery under general anesthesia were enrolled and randomly assigned to either the CPV group in which they received a tidal volume of 7 ml/kg with fixed PEEP level of 5 cmH2O or the OLA group in which they had alveolar recruitment maneuver followed by individualized PEEP. The primary outcome was the early postoperative pulmonary complications during the first 5 days after surgery. Secondary outcomes included lung mechanics, gas exchange, and hemodynamics during the intraoperative period as well as length of hospital stay, postoperative extrapulmonary complications, and intrahospital mortality. Results Postoperative pulmonary complications in the first 5 days were significantly higher in the CPV than in the OLA group. During the intraoperative period, the static compliance, the PEEP, and plateau pressure were significantly higher in the OLA group than the CPV group. On the contrary, driving pressure was significantly lower in the OLA group. Better oxygenation was observed in the OLA group in the intraoperative period and postoperative days 1 and 3. Pulmonary function tests were significantly better among patients who received the OLA on the first and third postoperative days. Conclusion The OLA may be used as an acceptable alternative to CPV as it was associated with less postoperative pulmonary complications, better intraoperative and postoperative oxygenation, and better postoperative pulmonary functions.