Deeper sedation with the anesthetic drug propofol may improve detection of serrated polyps in patients undergoing colonoscopy to screen for colorectal cancer, according to a recent study published by Quaye et al in Anesthesiology.
Background
Nearly all colorectal cancers start as polyps. Identifying and removing polyps during colonoscopy screening may prevent them from developing into cancer. However, compared with more common adenomatous polyps, serrated polyps are often difficult to detect because they are flatter and blend into the folds of the colon tissue.
Propofol is an alternative to moderate sedation for colonoscopy. Previous research has shown that propofol-based anesthesia may be more efficient and improve patient and provider satisfaction ratings.
“Propofol results in deeper sedation and also begins to work and wears off more quickly compared to [moderate] sedation,” explained lead study author Aurora N. Quaye, MD, a member of the Acute Pain and Regional Anesthesia Service at the Maine Medical Center.
Study Methods and Results
In the recent study, investigators used the New Hampshire Colonoscopy Registry to examine data on more than 54,000 colonoscopies completed between 2015 and 2020 in patients older than age 50. They then compared the polyp detection rates for serrated and adenomatous polyps among patients receiving either propofol-based anesthesia or moderate sedation.
The investigators found that the overall polyp detection rate was higher when colonoscopy was performed using propofol-based anesthesia vs moderate sedation (34% vs 24.5%). The results were similar on analysis of a “restricted” sample of about 19,000 colonoscopies performed at facilities that did not predominantly use one type of sedation over the other. In this population, the overall polyp detection rate was 30.3% among those who underwent colonoscopies with propofol-based anesthesia vs 25.7% among those who underwent colonoscopies with moderate sedation.
After adjusting for other confounding factors among the group of 19,000 colonoscopies, propofol-based anesthesia was still associated with a clinically and statistically significant 13% higher likelihood of detection of serrated polyps; however, there was no statistically significant difference in the detection of polyps between procedures using propofol-based anesthesia or moderate sedation.
Conclusions
Although the findings were strengthened by the use of systematically collected clinical registry data, the investigators noted that the research couldn’t provide any information on how propofol-based anesthesia might improve detection of serrated polyps.
“It may be that propofol increases patient comfort and relaxation, optimizing detection of polyps that are more difficult to see. Additionally, propofol may cause smooth muscle relaxation in the colon, allowing more careful inspection and improved visualization,” suggested Dr. Quaye. “Our study provides the first evidence that monitored anesthesia care with propofol might increase detection of serrated polyps. Propofol-based anesthesia may contribute to a more effective screening process for colorectal cancer, especially in patients with risk factors for serrated polyps. The findings … may bring us closer to our goal of further optimizing the use of colonoscopy for the prevention and early detection of colorectal cancer,” she emphasized.
The modest but significant reported association between propofol use and detection of serrated polyps may illustrate the potential and risk of studies using clinical registry data. Although the investigators warned that the results must be interpreted with caution as a result of limitations in analyzing registry data, they highlighted the importance of preserving access to propofol and called for further, rigorously conducted studies focusing on the value of anesthesia care for patients undergoing colonoscopy.
Disclosure: For full disclosures of the study authors, visit pubs.asahq.org.
