Routine versus "on demand" sedation and analgesia for colonoscopy: a prospective randomized controlled trial

The safety and tolerance of routine sedation and analgesia versus "on demand" sedation were compared in patients undergoing colonoscopy.

Two hundred forty-nine outpatients were randomly assigned to one of two groups. Group A (n = 125) received midazolam, 0.07 mg/kg intravenously plus meperidine, 0.77 mg/kg intravenously immediately preceding the colonoscope insertion. Group B (n = 124) received the same medication upon request during the procedure. Tolerance was assessed 24 hours later by phone interview performed by a nurse blinded to the medication regimen administered.

Eighty-three patients (66%) in Group B required sedation during colonoscopy. Among men in Group B more than 60 years of age, only 23% required sedation. The proportion of patients reporting moderate or severe pain (34% vs. 12.1%, p < 0.001) and of those stating they would not be willing to undergo colonoscopy again in the future (22% vs. 9.7%, p < 0.005) was significantly higher in the "on demand" sedation group. By multivariate analysis the randomization group was the single variable independently associated with both such outcomes. The frequency of side effects was similar in the two groups.

Administration of sedative and analgesic drugs routinely before colonoscopy is superior to "on demand" sedation in terms of tolerance and is not associated with an increase in side effects.