Background: A propofol target-controlled infusion (TCI) is often proposed for the management of difficult airway intubation and fibreoptic intubation under anaesthesia and spontaneous ventilation. No data are available about sevoflurane. The aim of the present study was to compare propofol and sevoflurane as hypnotics during fibreoptic intubation under spontaneous ventilation.
Methods: After regional ethical committee approval, 52 ASA I-II patients without any predictors for difficult intubation gave their informed consent. They were randomly assigned to one of two groups. After 3 min of pre-oxygenation, patients received either propofol with a plasmatic target concentration of 4 mg/l (group P; n= 26) or sevoflurane 4% with tidal volume ventilation (group S; n= 26). After 2 min, propofol was increased by 1 mg/l and sevoflurane was increased by 1% every 2 min until there was no reaction during mandible translation. This concentration was maintained for 4 min before starting nasotracheal fibrescopy for intubation. During both induction and fibrescopy, pulse oximetry, bispectral index (BIS), heart rate, and arterial blood pressure were monitored. Quality of intubation and operator satisfaction were evaluated. Data were compared using Student's t-test, Mann-Withney U-test or chi-square test. A P-value < 0.05% was considered to be significant.
Results: During induction, no difference in pulse oximetry, BIS values at the end of induction, or duration of induction were noticed. Five episodes of desaturation under 90% occurred during fibreoptic intubation in group P compared with none in group S.
Conclusion: Sevoflurane provides good fibreoptic intubation conditions to spontaneously breathing patients without any hypoxemic episodes such as those observed with propofol.