Cardiovascular effects of fibrescope-guided nasotracheal intubation

The cardiovascular effects of fibrescope-guided nasotracheal intubation were compared to those of a control group of patients who were intubated using the Macintosh laryngoscope. The 60 patients studied received a standard anaesthetic technique which included a muscle relaxant and were allocated randomly to one of two groups immediately before tracheal intubation. Systolic and diastolic arterial pressures in the fibreoptic group were significantly lower than in the control group during the first minute after intubation. The maximum increase in diastolic pressure was significantly lower in the fibreoptic group. The heart rate in the fibreoptic group was significantly higher than in the control group during all five minutes after intubation. The maximum increase in heart rate was significantly higher in the fibreoptic group. The cardiovascular responses to fibreoptic nasotracheal intubation under general anaesthesia should not cause undue concern in fit patients, but appropriate measures should be taken to prevent excessive tachycardia in compromised patients.