Cardiovascular effects of nasotracheal intubation.

Intubation time, arterial pressure, heart rate and arterial oxygen saturation during nasotracheal intubation effected with the Macintosh laryngoscope blade were compared with those during orotracheal intubation. The 60 patients studied received a standardised general anaesthetic and were randomly allocated to one of two groups immediately before tracheal intubation. The mean nasal intubation time (33.2 seconds) was significantly greater than mean oral intubation time (14.8 seconds). The mean arterial pressure changes in the nasal group were significantly greater and more prolonged than in the oral group. The mean heart rate in the nasal group was significantly lower than in the oral group during the first minute after intubation, after which heart rates were similar. There were no significant differences between the two groups with regard to arterial oxygen saturation levels at any stage.