From the AGA Journals

VIDEO: Anesthesia services during colonoscopy increase risk of near-term complications

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Anesthesia during colonoscopy may not be worth the cost

We are approaching a time when half of all colonoscopies are performed with anesthesia assistance, most using propofol. Undeniably, some patients require anesthesia support for medical reasons, or because they do not sedate adequately with opiate-benzodiazepine combinations endoscopists can administer. The popularity of propofol-based anesthesia for routine colonoscopy, however, is based on several perceived benefits: patient demand for a discomfort-free procedure, rapid sedation followed by quick recovery, and good reimbursement for the anesthesia service itself, added to the benefits of faster overall procedure turnaround time. And presently, there is no disincentive — financial or otherwise — to continuing or expanding this practice. Colonoscopy with anesthesia looks like a win-win for both patient and endoscopist, as long as the added cost of anesthesia can be justified.

However, while anesthesia-assisted colonoscopy appears to possess several advantages, growing evidence suggests that a lower risk of complications is not one of them.

A smaller study (165,000 colonoscopies) using NCI SEER registry data suggested that adding anesthesia to colonoscopy may increase some adverse events. Cooper et al. (JAMA Intern Med. 2013;173:551-6) showed an increase in overall complications and, specifically, aspiration, although not in technical complications of colonoscopy, including perforation and splenic rupture. However, this study did not include patients who underwent polypectomy. Wernli, et al. now show evidence derived from over 3 million patients demonstrating that adding anesthesia to colonoscopy increases complications significantly — not only aspiration, but also technical aspects of colonoscopy, including perforation, bleeding, and abdominal pain.

Colonoscopy is extremely safe, so complications are infrequent. Thus, data sets of colonoscopy complications large enough to be statistically meaningful for studies of this type require an extraordinarily large patient pool. For this prospective, observational cohort study, the authors obtained the large sample size by mining administrative claims data for 3 years, not through examining clinical data. As a result, several assumptions were made. These 3 million colonoscopies represented all indications — not just colorectal cancer screening. Billing claims for anesthesia represented surrogate markers for administration of propofol-based anesthesia. While anesthesia assistance was associated with increased risk of perforation, hemorrhage, abdominal pain, anesthesia complications, and stroke; risk of perforation associated with anesthesia was increased only in patients who underwent polypectomy.

Study methodology and confounding variables aside, it is hard to ignore the core message here: a large body of data analyzed rigorously demonstrate that anesthesia support for colonoscopy increases risk of procedure-related complications.

Patients who are ill, have certain cardiopulmonary issues, or do not sedate adequately with moderate sedation benefit from anesthesia assistance for colonoscopy. But for patients undergoing routine colonoscopy, without such issues, who could safely undergo colonoscopy under moderate sedation without unreasonable discomfort, we must now ask ourselves and discuss with our patients honestly, not only whether the added cost of anesthesia is reasonable — but also whether the apparent added risk of anesthesia justifies perceived benefits.

Dr. John A. Martin is senior associate consultant and associate professor, associate chair for endoscopy, Mayo Clinic, Rochester, Minn. He has no conflicts of interest to disclose.




Receiving anesthesia services while undergoing a colonoscopy may not be in your patients’ best interest, as doing so could significantly increase the likelihood of patients experiencing serious complications within 30 days of the procedure.

This is according to a new study published in the April issue of Gastroenterology, in which Dr. Karen J. Wernli and her coinvestigators analyzed claims data, collected from the Truven Health MarketScan Research Database, related to 3,168,228 colonoscopy procedures that took place between 2008 and 2011, to determine whether patients who received anesthesia were at a higher risk of developing complications after the procedure (doi: 10.1053/j.gastro.2015.12.018).

Source: American Gastroenterological Association

“The involvement of anesthesia services for colonoscopy sedation, mainly to administer propofol, has increased accordingly, from 11.0% of colonoscopies in 2001 to 23.4% in 2006, with projections of more than 50% in 2015,” wrote Dr. Wernli of the Group Health Research Institute in Seattle, and her coauthors. “Whether the use of propofol is associated with higher rates of short-term complications compared with standard sedation is not well understood.”

Men and women whose data was included in the study were between 40 and 64 years of age; men accounted for 46.8% of those receiving standard sedation (53.2% women) and 46.5% of those receiving anesthesia services (53.5% women). A total of 4,939,993 individuals were initially screened for enrollment, with 39,784 excluded because of a previous colorectal cancer diagnosis, 240,038 for “noncancer exclusions,” and 1,491,943 for being enrolled in the study less than 1 year.

Standard sedation was done in 2,079,784 (65.6%) of the procedures included in the study, while the other 1,088,444 (34.4%) colonoscopies involved anesthesia services. Use of anesthesia services resulted in a 13% increase in likelihood for patients to experience some kind of complication within 30 days of colonoscopy (95% confidence interval, 1.12-1.14). The most common complications were perforation (odds ratio, 1.07; 95% CI, 1.00-1.15), hemorrhage (OR, 1.28; 95% CI, 1.27-1.30), abdominal pain (OR, 1.07; 95% CI, 1.05-1.08), complications secondary to anesthesia (OR, 1.15; 95% CI, 1.05-1.28), and “stroke and other central nervous system events” (OR, 1.04; 95% CI, 1.00-1.08).

Analysis of geographic distribution of colonoscopies performed with and without anesthesia services showed that all areas of the United States had a higher likelihood of postcolonoscopy complications associated with anesthesia except in the Southeast, where there was no association between the two. Additionally, in the western U.S., use of anesthesia services was less common than in any other geographic area, but was associated with a staggering 60% higher chance of complication within 30 days for patients who did opt for it.

“Although the use of anesthesia agents can directly impact colonoscopy outcomes, it is not solely the anesthesia agent that could lead to additional complications,” the study authors wrote. “In the absence of patient feedback, increased colonic-wall tension from colonoscopy pressure may not be identified by the endoscopist, and, consistent with our results, could lead to increased risks of colonic complications, such as perforation and abdominal pain.”

Dr. Wernli and her coauthors did not report any relevant financial disclosures.

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