Comparison of volume-controlled and pressure-controlled ventilation in the Trendelenburg position for gynecological laparoscopic surgery

ABSTRACT

BACKGROUND: Minimal invasive gynecologic surgery usually requires pneumoperitoneum and Trendelenburg positioning, which results in adverse effects on respiratory and hemodynamic parameters. The aim of this study was to investigate the effects of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) introduced sequentially in patients who underwent gynecological laparoscopy on respiratory mechanics, cardiovascular responses, and gas exchange. METHODS: Forty patients who were scheduled for gynecologic laparoscopic surgery were enrolled. Baseline ventilation of their lungs was performed with VCV with a tidal volume (TV) of 8 ml/kg ideal body weight (IBW). Forty minutes after pneumoperitoneum and Trendelenburg positioning, the ventilation mode was changed to PCV, and airway pressure was set to provide a TV of 8 ml/kg IBW without exceeding 35 cmH2O. Respiratory mechanics and hemodynamic and gas exchange parameters were recorded at 10 minutes after induction, 30 minutes after CO2 pneumoperitoneum and Trendelenburg positioning, 30 minutes after PCV, and 30 minutes after desufflation and supine position. RESULTS: After pneumoperitoneum and Trendelenburg positioning, there were significant increases in systolic blood pressure, diastolic blood pressure, central venous pressure, peak airway pressure (PAP), mean airway pressure (Pmean), whereas lung compliance and PaO2 significantly decreased. The decrease in PAP and increases of Pmean, lung compliance and PaO2 were observed during PCV compared with VCV (P < 0.05). There were no differences in hemodynamic parameters between VCV and PCV. CONCLUSIONS: Our results demonstrated that PCV may be an effective method of ventilation during gynecologic laparoscopy in terms of improved oxygenation and minimizing adverse respiratory mechanics.