A clinical trial of volume- versus pressure-controlled intra-operative ventilation during laparoscopic bariatric surgeries

Abstract Objective To test the non-inferiority of pressure-controlled ventilation (PCV) to volume-controlled ventilation (VCV) in respiratory mechanics. Design Randomized open-labeled clinical trial Settings Bariatric Surgery Center Participants 66 individuals with morbid obesity patients undergoing laparoscopic bariatric surgeries Intervention Intra-operative ventilation with pressure-controlled mode (PCV) or volume-controlled mode (VCV). Measurements Peak and mean airway pressures, partial pressures of arterial oxygen (PaO2), arterial (PaCO2) end-tidal carbon dioxide (CO2) were analyzed. We additionally collected pulse-oximetric oxygen saturation, inspiratory concentration of oxygen (FiO2) and hemodynamic variables. Data were analyzed with repeated measures over the time of intubation (T1), after peritoneal insufflation (T2), and every 15 minutes, thereafter up to one hour. Results PCV mode was successful to sustain adequate ventilation in 97% of the patients which was similar to 94% success rate of the VCV mode. Peak airway pressure increased 6 cmH2O and end-tidal CO2 rose by 5 mmHg following abdominal insufflation in both groups (P = 0.850 and 0.376). Alveolar-arterial oxygen gradient similarly increased within 30 minutes after tracheal intubation both in PCV and VCV groups with small trend of being higher in the VCV group. The ratio of dead space to tidal volumes VD/VT did not have a meaningful change (P=0.724). Conclusion PCV was non-inferior to VCV during laparoscopic bariatric surgery. Either mode of ventilation could be alternatively used during the anesthesia care of these patients.