RESUMO
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 (VT) was 8mL/kg and the respiratory rate was adjusted to avoid hypercarbia. MEASUREMENTS: The peak and mean inspiratory pressures, dynamic compliance, exhaled VT, oxygenation index and physiological dead space were calculated and recorded at T1, 5minutes after induction of anesthesia in supine position, T2, 5minutes after stabilization of pneumoperitoneum, T3 and T4, 15 and 60minutes 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.
