Repeated alveolar recruitment maneuvers with and without positive end-expiratory pressure during bariatric surgery: a randomized trial.

BACKGROUND: Positive end-expiratory pressure (PEEP) is considered essential in protective ventilation, while it may lead to hemodynamic impairment. In the present study, we investigated the effect of repeated alveolar recruitment maneuvers (ARMs) with or without additional PEEP on the arterial oxygenation of obese patients who were undergoing bariatric surgery.

METHODS: Thirty-six obese adult patients with Body Mass Index >40 kg/m2 who were scheduled for laparoscopic sleeve gastrectomy were randomly allocated into three groups: 1) control group, no intraoperative ARMs; 2) ARM+ZEEP group, repeated ARMs every 30 minutes without extra PEEP; or 3) ARM+PEEP group, ARMs followed by 8 cmH2O of PEEP from the onset of pneumoperitoneum. Arterial oxygenation, respiratory mechanics, hemodynamics, and postoperative outcomes were investigated.

RESULTS: Patients in the ARM+PEEP group had significantly higher peak and plateau airway pressures during pneumoperitoneum, and more subjects required treatment with vasoconstrictors intraoperatively compared to patients in the other groups. Patients in the two ARMs treated groups had lower driving pressure during pneumoperitoneum and better arterial oxygenation in the emergence stage compared to patients in the control group. The PaO2/FiO2 ratio was 299±30, 315±39 and 245±43 mmHg in the ARM+ZEEP, ARM+PEEP, and control group, respectively (P<0.05 compared to control). There were no significant differences in the postoperative recovery variables between the groups.

CONCLUSIONS: Repeated ARMs, either with or without PEEP, improve early postoperative oxygenation and shorten time to extubation. ARMs without PEEP result in lower airway pressure and less hemodynamic impairment in patients who were undergoing bariatric surgery.