A randomized comparison of volume- and pressure-controlled ventilation in children with the i-gel

BACKGROUND The i-gel provides good airway sealing but gastric insufflation may occur when peak inspiratory pressure (PIP) exceeds the sealing pressure of the i-gel without a gastric tube. Pressure-controlled ventilation (PCV) provides lower PIP compared with volume-controlled ventilation (VCV) and low PIP may reduce the incidence of gastric insufflation in children during positive pressure ventilation. This study was designed to evaluate PIP, oropharyngeal leak pressure, and gastric insufflation during VCV or PCV in children undergoing general anesthesia with i-gel without a gastric tube in situ. METHODS A prospective, randomized-controlled study was conducted. Thirty-four children, aged 6 to 84 months, were randomly allocated into the VCV or PCV group. Fiberoptic bronchoscopy was performed to confirm appropriate position of i-gel. Oropharyngeal leak pressure and PIP were measured after i-gel insertion, after caudal block, and after surgery. Ultrasonography was performed to detect gastric insufflation. Gastric tube was not inserted. RESULTS PIP in cm H2O was significantly lower in the PCV group than in the VCV group after i-gel insertion (10 [9-12] vs 12 [11-15], P = .021), after caudal block (11 [10-12] vs 13 [11-15], P = .014), and after surgery (10 [10-12] vs 13 [11-14], P = .002). There was no difference in the incidence of gastric insufflation between the 2 groups (4/17 in the VCV group and 3/17 in the PCV group) (P > .999). CONCLUSION When i-gel was used without a gastric tube, gastric insufflation occurred regardless of the ventilation modes, which provided different PIP.