Optimizing ventilation strategies in laparoscopic gynecologic surgery in the steep trendelenburg position: A prospective randomized controlled trial comparing volume-controlled, pressure-controlled, and pressure-controlled volume-guaranteed ventilation

INTRODUCTION: Laparoscopic gynecologic surgery in the steep Trendelenburg position alters pulmonary mechanics and oxygenation. The optimal ventilation mode remains uncertain.
METHODS: In this prospective, randomized controlled trial, 60 patients (20 per group) undergoing elective laparoscopic gynecologic surgery in the steep Trendelenburg position were randomly assigned to Volume-Controlled Ventilation (VCV), Pressure-Controlled Ventilation (PCV), or Pressure-Controlled Volume-Guaranteed Ventilation (PCV-VG®). The primary outcome was peak airway pressure (Ppeak). Secondary outcomes included other respiratory variables, oxygenation parameters, and hemodynamic variables.
RESULTS: Ppeak and Pplateau values were significantly higher in the VCV group compared to the PCV and PCV-VG® groups at T2, T3, and T4 (p<0.01). After Bonferroni correction, these differences remained significant between VCV and the other groups, while no difference was found between PCV and PCV-VG®. PaCO2 levels were significantly lower in the PCV-VG® group compared to VCV and PCV at T3 (p=0.008). No significant differences were observed in PaO2, SaO2, Pmean, exhaled tidal volume, or hemodynamic parameters.
DISCUSSION AND CONCLUSION: Both PCV and PCV-VG® provided lower airway pressures and better lung compliance than VCV, while PCV-VG® additionally improved CO2 elimination. PCV-VG® may be a favorable ventilation strategy in laparoscopic gynecologic surgery performed in the steep Trendelenburg position.

Keywords: Laparoscopy, peak inspiratory pressure, pulmonary gas exchange, trendelenburg position, ventilator modes