Warm water infusion versus air insufflation for unsedated colonoscopy: a randomized, controlled trial

Abstract

Background: Uncontrolled data suggest that warm water infusion (WWI) instead of air insufflation (AI) during the insertion phase of unsedated colonoscopy improves patient tolerance and satisfaction.

Objective: We tested the hypothesis that water could increase the proportion of patients able to complete unsedated colonoscopy and improve patient tolerance compared with the conventional procedure.

Design: Randomized, controlled trial.

Setting: Single center, community hospital.

Patients: Consecutive outpatients agreeing to start colonoscopy without premedication.

Methods: Patients were randomly assigned to either WWI or AI insertion phase of colonoscopy. Sedation and/or analgesia were administered on patient request if significant pain or discomfort occurred.

Main outcome measurements: Percentage of patients requiring sedation/analgesia. Pain and tolerance scores were assessed at discharge by using a 100-mm visual analog scale.

Results: A total of 230 subjects (116 in the WWI group and 114 in the AI group) were enrolled. Intention-to-treat analysis showed that the proportion of patients requesting sedation/analgesia during the procedure (main outcome measurement) was 12.9% in the WWI group and 21.9% in AI group (P = .07). Cecal intubation rates were 94% in the WWI group and 95.6% in the AI group (P = .57). Median (interquartile range) scores for pain were 28 (12-44) and 39 (14-54) in WWI and AI groups, respectively (P = .05); corresponding figures for tolerance were 10 (3-18) and 14 (5-42), respectively (P = .01). The adenoma detection rates were 25% and 40.1% for the WWI and AI groups, respectively (P = .013).

Limitations: Single-center study, endoscopists not blinded to randomization.

Conclusions: WWI instead of AI is not associated with a statistically significant decrease in the number of patients requiring on-demand sedation, although it significantly improves the overall patient tolerance of colonoscopy. The finding of a lower adenoma detection rate in the WWI group calls for further evaluations. (

Clinical trial registration number: NCT00905554).