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.

Segmental increases in force application during colonoscope insertion: quantitative analysis using force monitoring technology.

BACKGROUND: Colonoscopy is a frequently performed procedure that requires extensive training and a high skill level. OBJECTIVE: Quantification of forces applied to the external portion of the colonoscope insertion tube during the insertion phase of colonoscopy. DESIGN: Observational cohort study of 7 expert and 9 trainee endoscopists for analysis of colonic segment force application in 49 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: Academic gastroenterology training programs. PATIENTS: Patients undergoing routine screening or diagnostic colonoscopy with complete segment force recordings. MAIN OUTCOME MEASUREMENTS: Axial and radial force and examination time. RESULTS: Both axial and radial force increased significantly as the colonoscope was advanced from the rectum to the cecum. Analysis of variance demonstrated highly significant operator-independent differences between segments of the colon (zones) in all axial and radial forces except average torque. Expert and trainee endoscopists differed only in the magnitude of counterclockwise force, average push/pull force rate used, and examination time. LIMITATIONS: Small study, observational design, effect of prototype device on insertion tube manipulation. CONCLUSION: Axial and radial forces used to advance the colonoscope increase through the segments of the colon and are operator independent.

Drug-induced liver disease 2004.

PURPOSE OF REVIEW: To summarize the salient reviews, studies and case reports and series that dealt with clinical, pathological, methodological, and epidemiological descriptions of drug-induced liver disease in the calendar year 2004. RECENT FINDINGS: While no new causes of drug-induced liver injury were reported for 2004, several new reports of previously recognized hepatotoxins, including herbal products, were published. These include the antiretroviral drugs for HIV and agents to manage tuberculosis. Acetaminophen (APAP) retained its preeminent position as the leading cause of drug-induced acute liver failure, currently accounting for nearly 50% of cases according to the latest figures from the U.S. Acute Liver Failure Study Group. Not surprisingly, APAP also heads the list of drugs and toxins leading to liver transplantation for acute hepatic failure. Efforts to reduce the number of cases of intentional APAP poisonings by restricting the number of tablets sold at any one time in the UK are ongoing, but the success of the program may be lessening, as was pointed out this year. The use of potentially hepatotoxic medications in patients with underlying liver disease was examined with the statins, and they emerged as a safe class for use in this setting. SUMMARY: Given the apparent increasing incidence of acute liver failure attributable to APAP in the US, additional efforts are still needed to better define the risks associated with its use and to further reduce the incidence of severe liver injury from this widely used agent.