A Trial Comparing Propofol to Midazolam Plus Meperidine Sedation for Outpatient Colonoscopy

Colonoscopy is an important diagnostic and therapeutic procedure. It is an invasive procedure, not well tolerated by most patients if performed without sedation. There is considerable variability in the practice of sedation for endoscopic procedures worldwide. There are some centers which perform a significant proportion of gastroscopies and colonoscopies without sedation. On the other hand, general anesthesia is given to more than 90% of patients undergoing colonoscopy in France. Most centers do use conscious sedation, usually in the form of benzodiazepines and/or narcotics, with propofol sedation reserved for difficult cases. Benzodiazepines and narcotics are effective and safe. However, the onset of sedation can be delayed, and in some patients conscious sedation is inadequate, resulting in a poor experience with the procedure. Moreover, there are significant post-sedation side effects, such as nausea, vomiting, and prolonged recovery period. This can substantially increase procedure costs due to the need for prolonged monitoring after endoscopy.

Propofol, a general anesthetic agent, has been routinely used in various procedures and surgeries. It has a fast onset of action (within 30-60 seconds), a short half life (1.8-4.1 minutes) but a narrow therapeutic window. The current package insert of propofol states that only persons trained in the administration of general anesthesia should administer propofol and these physicians should not be involved in the procedure so that patients can be continuously and properly monitored due to the risk of respiratory depression. No deaths associated with propofol sedation have been reported since it was first introduced in gastrointestinal endoscopy in the mid 1980. However, need for mechanical ventilation as a result of propofol sedation has been reported. In a number of small trials propofol was shown to have a superior recovery profile following various endoscopic procedures including gastroscopy, colonoscopy and endoscopic retrograde cholangiopancreatography (ERCP). Indeed, propofol sedation is now used routinely in elective adult procedures in some centers. However, the lower cost of recovery is offset by the need for an anesthesiologist. Therefore, the use of propofol sedation is limited to selected endoscopic procedures or patients.

Although a number of small randomized trials have explored the efficacy of propofol sedation, the evidence is not definitive. Thus we conducted this study to determine if propofol sedation leads to shorter recovery times in elective outpatient colonoscopy compared to usual care.

Inclusion criteria

• outpatient colonoscopy

Exclusion criteria

• allergy to propofol , midazolam, meperidine, eggs or soybean
• history of colonic resection
• inability to understand spoken/written English
• dementia
• pregnancy
• unwillingness to participate in the study