Intermittent thiopentone for teaching fibreoptic nasotracheal intubation

A technique for teaching fibreoptic nasotracheal intubation is described. Fifty patients presenting for elective dental surgery received thiopentone by intermittent injection for induction and maintenance of anaesthesia whilst a trainee anaesthetist attempted to visualise the vocal cords using an intubating fibrescope. During endoscopy patients spontaneously breathed oxygen-enriched air and passage of the tracheal tube was facilitated by suxamethonium. Arterial blood pressure, heart rate and arterial oxygen saturation were monitored continuously. Time from loss of eyelash reflex to successful intubation was 113 (90) (35-480) s (mean (SD) (range)). Changes in arterial blood pressure and heart rate were similar to those described in previous studies of tracheal intubation. Haemoglobin oxygen saturation remained above 95% in 43 patients, and above 93% in 46 patients; the lowest saturation recorded was 91%. Intermittent thiopentone provides good conditions for teaching fibreoptic nasotracheal intubation whilst maintaining arterial blood pressure and oxygen saturation.