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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

TRIAL REGISTRATION: Brazilian Registry of Clinical Trials, RBR-5tbdpy5. Registered on January 29, 2024.