Total Intravenous versus Inhalational Anaesthesia for Colonoscopy: A Prospective Study of Clinical Recovery and Psychomotor Function

A randomized, prospective study was conducted on 69 patients comparing recovery after two different anaesthetic techniques for ambulatory colonoscopy. Thirty-five patients received an intravenous fentanyl (1 microg/kg), midazolam (0.05 to 0. 075 mg/kg) and propofol (10 to 20 mg boluses as required) combination. 34 patients received sevoflurane in 67% nitrous oxide. Drug administration was titrated to clinical signs. At baseline and 30, 60, 90 and 120 minutes after the procedure patient performance on a comprehensive battery of psychomotor tests was recorded. Emergence times were noted. Depth of sedation was assessed at 5 minute intervals for 30 minutes after the end of the procedure. Emergence times were faster in the fentanyl/midazolam/propofol group by 2.2 minutes. A lower sedation score was detected at 20 minutes in the sevoflurane/nitrous oxide group. Psychomotor impairment was of a greater magnitude and more prolonged by 30 to 90 minutes in the fentanyl/midazolam/propofol group. It is concluded that a sevoflurane/nitrous oxide anaesthetic has a suitable recovery profile for ambulatory colonoscopy and results in faster recovery of cognitive function compared with a fentanyl, midazolam and propofol combination.