Z Gastroenterol 2012; 50 - K285
DOI: 10.1055/s-0032-1324220

Warm Water Infusion Colonoscopy: Review and Meta-Analysis

T Rabenstein 1, F Radaelli 2, O Zolk 3
  • 1Diakonissen-Stiftungs-Krankenhaus Speyer, Innere Medizin, Gastroenterologie, Gastrointestinale Onkologie, Speyer, Germany
  • 2Divisione de Gastroenterologica, Como, Italy
  • 3Lehrstuhl für Klinische Pharmakologie und Klinische Toxikologie, Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Erlangen, Germany

Background and study aims: Warm water infusion (WI) instead of traditional air insufflation (AI) during the insertion phase of colonoscopy has been proposed to reduce the pain and to improve patients' acceptance of the procedure. The aim of this systematic review was to compare WI against standard AI according to findings from randomized controlled trials (RCTs).

Methods: A systematic review and meta-analysis of RCTs comparing WI with standard AI was conducted. Primary outcome measures were procedure- (cecal intubation and adenoma detection rates) and patient-related (pain, need for sedation) parameters.

Results: Nine studies, involving 1283 patients, were included. The final meta-analysis revealed a higher risk for failures in reaching the cecum using WI as compared to AI in the intention to treat analysis (risk ratio [RR] 4.04, confidence interval [CI] 2.13 to 7.68, P<0.0001). Even when short air insufflations would have been permitted during WI colonoscopy the difference remained significant ([RR] 2.25, [CI] 1.13 to 4.15], P<0.02). The cecal intubation time, however, was similar between WI and AI (P=0.62). Patients experienced significantly less pain (mean difference in the visual analogue score for pain –1.18, CI –1.47 to –0.88, P<0.00001) and a significantly lower proportion of them requested sedation and/or analgesia during colonoscopy (RR 0.48, CI 0.35 to 0.66, P<0.00001) when WI was applied as compared to AI. No significant difference in the adenoma detection rate was observed between WI and AI (RR 0.95, CI 0.81 to 1.10, P=0.49).

Conclusions: The WI technique is less painful than standard AI, reduces the need for sedation and analgesia and improves patients' acceptance of colonoscopy. WI was not inferior to AI for both adenomas detection and the safety of the procedure. Under study conditions failure of cecal intubation was more common with WI, but the clinical significance of this finding is not clear, since short air insufflations in a routine setting might compensate this handicap.