The Administration of Hyoscine N-butyl Bromide During Colonoscopy Does Not Increase the Adenoma Detection: A Randomized, Double-blind, Controlled Study

Abstract

Purpose: The administration of anti-spasmotic drugs during colonoscopy has been proposed to increase the adenoma detection rate (ADR). However, conflicting results have been reported on the impact of Hyoscine N-butyl-bromide (HBB) on ADR. The primary outcome of the study was to test whether the administration of HBB, at time of cecal intubation, increases the polyp and adenoma detection. The HBB safety, the entity of abdominal distension at the end of the procedure and the patient's bloating perception were also evaluated. Methods: Consecutive colonoscopy adult outpatients were considered for the study. Exclusion criteria were represented by co-morbidities regarded as contraindications to HBB administration, previous intestinal resection and history of IBD. After cecal intubation, patients were randomized in a double blind fashion to receive either 20 mg/1ml of HBB i.v. or 1ml i.v. of placebo (saline). The number, size, histology and location of polyps and the occurrence of episodes of significant tachycardia (defined as bpm>140 persisting for more than 30 sec.) were recorded. The air retained in the abdomen at the end of the procedure was indirectly estimated by calculating the δAC (difference in the abdominal circumference measured before and after colonoscopy). At discharge the bloating perceived by the patient was measured by means of a VA scale (range 0-100). A sample size of at least 400 patients was calculated, by hypothesizing an increase of ADR (primary outcome measure) from 28% to 43% (α=0.05, β=0.9). Results: 402 patients (mean age 57.7+12.5 years; 44% men) were randomized to receive either HBB (202 patients) or saline (200 patients). No difference was observed as concerns polyp detection rate, ADR, advanced-ADR, mean number of polyps detected per-patient in the HBB and saline groups (see Table). Significant tachycardia was observed in 2.9% of HBB patients and in 0.5% of those receiving saline (p=ns). The δAC was similar between patients receiving HBB or saline (mean+SD 2.5+2.8 cm and 2.2+2.3 respectively; p=ns) as well as the bloating perception (VAS mean+SD 12.9+13.0 and 13.9+12.9 respectively; p=ns).Table: No Caption available.Conclusion: HBB administered before colonoscopy withdrawal phase does not increase the polyp and adenoma detection. The medication is well tolerated and it does not increase either the abdominal distension or the bloating perceived by patients at discharge.