Comparison of vital capacity induction with sevoflurane to intravenous induction with propofol in adult patients

BACKGROUND: Various techniques exist for gaseous induction in adults. Vital capacity induction (VCI) is a special technique for gaseous induction of anesthesia. AIMS: We compared the two methods for time of induction, vital parameters at induction, and suitability for laryngeal mask insertion and its effects, if any on the emergence and postoperative cognitive function tests. SETTINGS AND DESIGN: A total of 60 adult American Society of Anesthesiologists grades I and II gynecological patients were randomly allocated into two groups of 30 each. MATERIALS AND METHODS: Group “S” received VCI with 8% sevoflurane in 8 l/min oxygen and group “P” received intravenous induction with propofol after premedication. Laryngeal mask airway (LMA) was inserted and anesthesia maintained with oxygen, nitrous oxide, and sevoflurane in both groups. Induction time, corresponding entropy, vital parameters, and emergence time were noted. Postoperative cognitive and psychomotor functions were noted with P-deletion test, digit symbol substitution test, and finger nose test. STATISTICAL ANALYSIS USED: Unpaired t-test and Fisher exact test. RESULTS: Time for induction was 61 ± 32 s and 31 ± 10.8 s for VCI (group S) and propofol (group P), respectively. The difference was statistically significant (P = 0.001). About 70% patients in VCI had excellent conditions for LMA insertion when compared with 76% in propofol group (P = 0.3855). The incidence of airway complications, emergence times, and recovery of postoperative cognitive functions was not significantly different in both groups. CONCLUSIONS: VCI provides an induction and recovery comparable to propofol induction.