Is routinely given conscious sedation of benefit during colonoscopy?

Background: Sedative drugs are generally given to patients undergoing colonoscopy. However, the benefit of routinely administered conscious sedation for colonoscopy has not been studied in adequately controlled trials. Methods: We randomly assigned 180 patients scheduled for diagnostic colonoscopy into 3 groups: (1) sedation with intravenous midazolam (midazolam group); (2) sedation with intravenous saline (placebo group); and (3) no intravenous cannula (control group). The endoscopist assessed the procedure immediately after the examination. The patients completed a questionnaire before leaving the endoscopy unit. Another questionnaire was sent to the patients 2 weeks after the examination. Answers were mainly given on a 100 mm visual analog scale. Results: Shortly after the procedure, the patients in the midazolam group rated the examination less difficult than those in the placebo group (30 vs. 40 mm; p < 0.05; visual analog scale, 0 to 100 mm: 0 = not at all, 100 = extremely). However, no significant difference was found between midazolam and control groups (30 vs. 36 mm, respectively), otherwise, there were no differences between the three groups with respect to the patients' or endoscopists' assessments or the examination time. Conclusions: Routinely administered sedation does not markedly increase patient tolerance or make colonoscopy technically easier.