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

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.