The Influence of Adding Diphenhydramine Before Initiation of Moderate Sedation with Midazolam and Pethidine for Improving Quality of Colonoscopy

Abstract

Background: Combination of Intravenous benzodiazepines with opiates appears to be essential in order to guarantee high quality of moderate sedation during colonoscopy. Diphenhydramine is recommended for endoscopic procedures in difficult-to-sedate patients However, the studies supporting its use have yielded conflicting results.

Objective: To assess the value of adding diphenhydramine hydrochloride before initiation of moderate sedation with midazolam and pethidine for Improving Quality of Sedation during colonoscopy.

Methods: We conducted a prospective, randomized, double-blind, placebo-controlled study of 150 Patients undergoing diagnostic colonoscopy. Of 150 patients, data were analyzed for 100 patients randomized into two groups: Diphenhydramine group (n = 53) received 50 mg of diphenhydramine intravenously before initiation of moderate sedation with pethidine and midazolam while in placebo group (n = 47) received placebo in addition to pethidine and midazolam. Amount of pethidine and midazolam used and Quality of sedation were assessed.

Results: The mean doses of pethidine was significantly higher in placebo group as compared to diphenhydramine group (69.9 ± 35.4 mg vs 61.2 ± 21.0 mg, p < 0.01) However, no significant difference between the two groups regarding midazolam mean dose (4.9.±2.1 mg vs 4.8 ± 2.0 mg,p = 0.786). More patients in diphenhydramine group were being very satisfied with the procedure as compared to those in placebo group (88.67% vs 59.57%,p < 0.001).Furthermore more endoscopist in diphenhydramine group were being very satisfied with the procedure as compared to those in placebo group (77.35% vs 51.06%,p < 0.001).

Conclusions: Intravenous diphenhydramine hydrochloride given before initiation of midazolam and pethidine offers a significant Improvement of Quality of moderate Sedation during colonoscopy without increasing the number of sedation related complications.

Keywords: Colonoscopy; Diphenhydramine; Moderate sedation.