Effect of PEEP titration on the incidence of elevated driving pressure in laparoscopic bariatric surgery: a randomized superiority trial

Suboptimal positive end-expiratory pressure (PEEP) settings may lead to cyclic lung overstress, especially in obese patients undergoing general anesthesia. We hypothesized that recruitment maneuver (RM) followed by driving pressure–guided PEEP titration – before and during pneumoperitoneum – would reduce the incidence of elevated driving pressure (> 15 cmH₂O) during pneumoperitoneum. In this single-center, randomized, superiority trial, obese patients undergoing laparoscopic bariatric surgery were allocated into three groups: (1) recruitment maneuver followed by driving pressure-guided PEEP titration (RMTP); (2) recruitment maneuver followed by fixed PEEP (6 cmH₂O) (RMFP); or (3) no recruitment maneuver with fixed PEEP (6 cmH₂O) (NRMFP). RM was performed with incremental PEEP (6→10→15→20 cmH₂O) and inspiratory pressure (26→30→35→40 cmH₂O), whereas PEEP titration was conducted in a decremental fashion. The primary outcome was the incidence of driving pressure > 15 cmH₂O. Eighty-five patients were screened and 78 randomized. No significant between-group differences in the incidence of driving pressure > 15 cmH₂O were observed before pneumoperitoneum or after pneumoperitoneum reversal. During pneumoperitoneum before RM, driving pressure > 15 cmH₂O occurred less frequently with RMTP than with RMFP and NRMFP (7.7% vs. 46.2% and 46.2%; RR 6.00, 95% CI 1.49–24.20; P = 0.01). After RM, the incidence remained lower with RMTP (3.8%) compared with RMFP (30.8%; RR 8.00, 95% CI 1.08–59.50; P = 0.04) and NRMFP (46.2%; RR 12.00, 95% CI 1.68–85.73; P = 0.01). Secondary outcomes, including postoperative pulmonary complications and hemodynamic variables, were similar between groups. Recruitment maneuver combined with driving pressure-guided PEEP titration improved intraoperative respiratory mechanics and reduced the incidence of elevated driving pressure during pneumoperitoneum, although no differences in postoperative clinical outcomes were observed. Brazilian Registry of Clinical Trials, RBR-5tbdpy5. Registered on January 29, 2024.