Impact of sedation on adenoma and polyp detection during colonoscopy: a systematic review and meta-analysis

The impact of sedation on colonoscopy quality indicators remains debated. We aimed to evaluate how sedation use and type influence adenoma detection rate (ADR) and polyp detection rate (PDR) during colonoscopy.

We searched MEDLINE, Embase, and the Cochrane Library for studies evaluating the impact of sedation on adenoma and polyp detection during colonoscopy. Primary outcomes were ADR and PDR. Secondary outcomes included advanced adenoma detection rate (AADR), caecal intubation rate (CIR), and colonoscopy withdrawal time (CWT). We used a random-effects meta-analysis to estimate risk ratios (RRs) with corresponding 95% confidence intervals (CIs).

A total of 45 studies comprising 878,780 colonoscopies were included in the final analyses. There were no statistically significant differences in ADR between sedated and unsedated colonoscopies (RR 1.04; 95% CI, 0.95-1.14), nor between deep sedation and conscious sedation (RR 1.04; 95% CI, 0.98-1.09). Similarly, PDR did not differ significantly when comparing sedation versus no sedation (RR 0.99; 95% CI, 0.96-1.03) or deep sedation versus conscious sedation (RR 1.04; 95% CI, 0.99-1.09). AADR and colonoscopy withdrawal times were similar across the sedation comparison groups. However, both sedation in general (p = 0.01) and deep sedation (p = 0.02) were associated with a marginal increase in CIR. The certainty of evidence for all outcomes was very low.

Current observational evidence does not demonstrate a consistent association between the use or depth of sedation and adenoma or polyp detection during colonoscopy. These findings should be interpreted cautiously given substantial between-study heterogeneity and the very low certainty of evidence.