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

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.