Deeper Sedation During Colonoscopy Linked to Improved Detection of Serrated Polyps

Detection of serrated polyps during colonoscopy improved significantly with the use of propofol-based versus conventional sedation, data from a large registry showed.

The detection rate increased from 24.5% with mild-moderate sedation to 34.0% with propofol. The detection rate with propofol remained significantly higher in a propensity-matched analysis. A logistic regression analysis showed that propofol-based sedation was associated with significantly higher detection rates for all neoplasms, adenomas, and serrated polyps. When logistic regression was applied to the propensity-matched population, the effect of propofol sedation remained significant only for serrated polyps.

In the absence of a randomized comparison of propofol and conventional sedation, the results cannot be considered definitive, reported Aurora N. Quaye, MD, of Maine Medical Center in Portland, and co-authors in Anesthesiology.

“Given the significant challenges inherent to serrated polyp detection, and the fact that missing these lesions undermines the effectiveness of colonoscopy in colorectal cancer prevention, strategies are needed to improve their identification,” the authors concluded. “As propofol use for colonoscopy continues to grow nationally, there is meaningful debate regarding the effectiveness of this practice.”

“Our study provides evidence that propofol use may be associated with increased serrated polyp detection,” they added. “Since these lesions may be the precursors for up to 30% of colorectal cancers, improving their detection may be of substantial benefit.”

The authors of an accompanying editorial noted that the study authors hypothesized that propofol sedation would improve detection of polyps that might progress to cancer. However, the final analysis showed only a modest association between propofol and detection of serrated polyps, but not adenomas or all neoplasms.

“Unfortunately, because the current analysis grouped both serrated adenomas and hyperplastic polyps within the single serrated polyp variable, it is not possible to infer whether propofol is associated with increased detection of serrated adenomas,” asserted Douglas A. Colquhoun, MBChB, of the University of Michigan in Ann Arbor, and co-editorialists.

The trial had several other limitations regarding the choice and use of propofol-based sedation but also had a number of strengths related to study design.

“Despite these limitations, this study still calls attention to the importance of preserving access to routine propofol use in patients undergoing screening and surveillance colonoscopy,” wrote Colquhoun and colleagues.

They noted that anesthesiologist-led sedation for endoscopic procedures has increased within the Veterans Affairs health system and U.S. commercial insurance market, but payers have recently proposed stopping reimbursement for anesthesiologist-led sedation for healthy patients undergoing low-risk procedures.

“To date, these proposals have been unsuccessful due to opposition from patients and physicians,” Colquhoun and co-authors continued. “In the case of screening colonoscopy, these coverage decisions could adversely impact early diagnosis, patient outcomes, and access to care due to reduced clinical throughput; this is alarming in the context of the increased care demand driven by recent consensus guidelines that lower the recommended age for initial screenings.”

Although use of propofol-based sedation for colonoscopy has increased in recent years, the impact on polyp detection has remained unclear, Quaye and co-authors noted in their introduction. A handful of studies attempted to determine the relationship between propofol sedation and polyp detection, but results have been conflicting and subjective to significant limitations related to sample size and adjustment for confounders.

In an effort to inform ongoing discussions, investigators analyzed patient records in the New Hampshire Colonoscopy Registry. The query specified patients ≥50 with adequate bowel preparation who underwent colonoscopies complete to the cecum from Jan. 1, 2015 to Feb. 1, 2020. The study period preceded the U.S. Preventive Services Task Force recommendation for screening colonoscopy beginning at 45. The analysis included screening and surveillance colonoscopies.

The principal outcomes of interest were detection of all neoplastic polyps, adenomatous polyps, and serrated polyps. The primary exposure was use of propofol-based sedation versus moderate sedation with benzodiazepines and opioids.

The full sample comprised 54,063 colonoscopies, 18,998 of whom were included in a propensity-matched analysis with clustering at the endoscopist level. Propofol sedation was used in 29,312 (54.22%) examinations. Screening examinations accounted for two-thirds of all colonoscopies.

In the full sample, propofol was associated with increased detection of any neoplasia (58.1% vs 51.8%), adenomas (39.5% vs 37.3%), and serrated polyps (34% vs 24.5%). Only the difference in serrated polyp detection achieved statistical significance. Logistic regression analysis produced odds ratios favoring propofol for neoplasia detection (OR 1.25, 95% CI 1.21-1.29), adenomas (OR 1.07, 95% CI 1.03-1.11), and serrated polyps (OR 1.51, 95% CI 1.46-1.57).

In the restricted sample, propofol was associated with modestly higher detection rates for all neoplasms (56.0% vs 54.6%) and serrated polyps (30.3% vs 25.7%), but not adenomas (40.2% vs 40.4%). By logistic regression analysis, the detection rate for serrated polyps remained significantly higher with propofol (OR 1.13, 95% CI 1.07-1.19), but not all neoplasms (OR 1.03, 95% CI 0.98-1.08) or all adenomatous polyps (OR 1.00, 95% CI 0.95-1.05).

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