Effect of propofol anesthesia on force application during colonoscopy

Background: Sedation is frequently used during colonoscopy to control patient discomfort and pain. Propofol is associated with a deeper level of sedation than is a combination of a narcotic and sedative hypnotic and, therefore, may be associated with an increase in force applied to the colonoscope to advance and withdraw the instrument. Objective: To compare force application to the colonoscope insertion tube during propofol anesthesia and moderate sedation. Design: An observational cohort study of 13 expert and 12 trainee endoscopists performing colonoscopy in 114 patients. Forces were measured by using the colonoscopy force monitor, which is a wireless, handheld device that attaches to the insertion tube of the colonoscope. Setting: Community ambulatory surgery center and academic gastroenterology training programs. Patients: Patients undergoing routine screening or diagnostic colonoscopy with complete segment force recordings. Main Outcome Measurements: Axial and radial forces and examination time. Results: Axial and radial forces increase and examination time decreases significantly when propofol is used as the method of anesthesia. Limitations: Small study, observational design, nonrandomized distribution of sedation type and experience level, different instrument type and effect of prototype device on insertion tube manipulation. Conclusions: Propofol sedation is associated with a decrease in examination time and an increase in axial and radial forces used to advance the colonoscope.