Heart rate and arterial pressure changes during fibreoptic tracheal intubation under general anaesthesia

The cardiovascular responses to fibreoptic orotracheal intubation under general anaesthesia were compared with those in a control group in whom tracheal intubation was effected with a Macintosh laryngoscope. The patients received a standard anaesthetic and were allocated randomly to either group immediately before intubation. Fibreoptic intubation took significantly longer to perform. There were significant increases in heart rate and arterial pressure in both groups compared with pre-induction values. The tachycardia in the fibreoptic group was significantly greater than that in the control group during the second minute after intubation, and the increase in systolic pressure was sustained for a longer period in the fibreoptic group. The maximum increases in systolic and diastolic pressures above pre-intubation values were significantly greater in the fibreoptic group. The cardiovascular responses associated with fibreoptic intubation under general anaesthesia appear to be more severe than those which follow intubation effected with a Macintosh laryngoscope.