Intubation without Muscle Relaxant: The Role of Sevoflurane

Background: Sevoflurane is preferred for induction of general anesthesia in pediatrics. We examined the minimum duration of sevoflurane administration resulting in most optimal intubation conditions. Methods: We included 75 children, aged 2-12 years, undergoing tonsillectomy under general anesthesia at Amir-Alam Hospital. They were given midazolam 0.05 mg/kg and fentanyl 2 mic/kg IV, five minutes before induction with sevoflurane 8% in 60% N2O and 40% O2 with total gas flow of 10 lit/min via face mask for 90 seconds (group I), 120 sec (group II) or 150 sec (group III), randomly. After tracheal intubation, intubation condition was assessed using Steyn s modification of Helbo Hansen scoring system. The total scores were divided into clinically acceptable (≤10) or unacceptable ( 10). Results: There was no statistically significant difference among the three groups in demographic characteristics. Mean ± SD of intubation scores were 10.04±2.9, 8.12±3.2, and 5.64±1.15 in groups 1-3, respectively (P 0.001) with statistically significant differences between all three groups: between groups I and II (P=0.044), I and III (P 0.001), as well as II and III (P=0.004). Intubation conditions were acceptable in 11, 16, and 25 patients in each group, respectively (P 0.001). Conclusion: Inhalation induction by sevoflurane 8% in 150s provides acceptable clinical situation for intubation in pediatrics.