Warm Water Irrigation versus Air Insufflation for Unsedated Colonoscopy: Preliminary Results of a Randomized Controlled Trial

Abstract

Purpose: In the colorectal cancer screening era, the increasing request for colonoscopy has determined the need to improve the efficiency of endoscopy services. Unsedated colonoscopy is characterized by lower costs and recovery time, although it may be painful and poorly tolerated by patients. Recent uncontrolled data suggest these drawbacks may be reduced by the use of warm water (37°C) irrigation in the insertion phase of unsedated colonoscopy. Present study is aimed to test in a prospective randomized controlled trial whether the use of warm water (WW) irrigation versus air (A) insufflation during the insertion phase of colonoscopy increases the proportion of patients able to complete the examination without sedation and the global tolerability of the examination itself. Methods: Consecutive 18-80 yr-old outpatients undergoing colonoscopy for routine indications and accepting to initiate the examination without sedation were enrolled and randomized to a WW or an A insertion phase, according to a computer generated list. Sedation and analgesia (midazolam plus meperidine) were administered on patient's demand, if significant discomfort or pain occurred during the procedure. Pain and tolerability scores were assessed by means of a visual analogic scale (VAS, range 0-10) at discharge; the willingness to repeat examination in the same conditions was assessed at discharge (time 0) and after 24 hours by phone (time 24). Proportions and means were compared by Chi-squared and Student t test, respectively. A sample size of at least 226 patients (113 in the WW, 113 in the A group) was calculated, by hypothesizing a decrease from 25% to 10% in the proportion of patients requiring on demand-sedation in the WW group (0.05 significance level, 80% power). Results: From April to June 2009, 192 subjects (99 in the WW and 93 in the A group) were enrolled (mean age 66.2 yrs, male 55.2%). Demographic features, quality of bowel cleansing and indication to colonoscopy were comparable in both groups. Main results of the study are shown in Table 1.TableConclusion: Preliminary results of present study suggest that the use of WW during the insertion phase of unsedated colonoscopy might improve its tolerability, although it does not increase the proportion of patients who are able to complete the examination without sedation. (ClinicalTrials.gov number, NCT00905554).