Comparison of volume-controlled ventilation and pressure-controlled ventilation volume guaranteed during laparoscopic surgery in Trendelenburg position

Study objective: To analyze the effects of pressure-controlled ventilation-volume guaranteed (PCV-VG) and volume controlled ventilation (VCV) on airway pressures and respiratory and circulatory indicators during laparoscopic surgery in Trendelenburg position. Design: Prospective randomized comparative clinical study. Setting: Tertiary hospital. Patients: Forty ASA physical status 1 and 2 patients who underwent elective laparoscopic surgery in Trendelenburg position. Interventions: Patients were randomly allocated to either VCV group (n = 20) or the PCV-VG group (n = 20). After induction of anesthesia, for both modes of ventilation, the target tidal volume (V_T) was 8 mL/kg and the respiratory rate was adjusted to avoid hypercarbia. Measurements: The peak and mean inspiratory pressures, dynamic compliance, exhaled V_T, oxygenation index and physiological dead space were calculated and recorded at T1, 5 minutes after induction of anesthesia in supine position, T2, 5 minutes after stabilization of pneumoperitoneum, T3 and T4, 15 and 60 minutes after 30° Trendelenburg position with pneumoperitoneum respectively. Main results: PCV-VG group had significantly lower peak inspiratory pressure and greater dynamic compliance than VCV group (P <.001). Conclusions: In patients who underwent laparoscopic surgery in Trendelenburg position, PCV-VG was superior to VCV in its ability to provide ventilation with lower peak inspiratory pressure and greater dynamic compliance.