ABSTRACT
BACKGROUND: Sevoflurane has been used to provide an inhaled induction by using a vital capacity breath, which is fast and has few side effects. We compared the clinical effects of a vital capacity inhalation induction (VCII) with sevoflurane in patients of preoxygenation or air-breathing before anesthetic induction. METHODS: After IRB approval, patients were randomly assigned to receive preoxygenation (O2 group, 70 patients) or air breathing (Air group, 70 patients) via SIBI (Single Breath Induction) connectorTM before VCII with 8% sevoflurane in 75% N2O/O2 from primed circuit. The clinical characteristics were compared between two groups in respect to prolongation of breath holding after loss of consciousness (response to verbal command) and side effects (airway, hemodynamic, motor) during VCII. RESULTS: O2 group showed lower incidence (60.0% vs. 87.1%, P < 0.05) and shorter duration (27.1 s vs. 36.4 s, P < 0.05) in prolongation of breath holding than Air group. Otherwise, there were no significant differences in clinical effects between two groups. CONCLUSIONS: We found that preoxygenation reduces the incidence and duration of prolongation of breath holding during VCII with sevoflurane compared with air-ventilation before VCII. We suggest that the prolongation of breath holding might be related to Hering-Breuer response to maximal lung inflation during VCII.