title: A randomized, controlled trial comparing real-time insertion pain during colonoscopy confirmed water exchange to be superior to water immersion in enhancing patient comfort.
abstract: BACKGROUND
  A recent American Society for Gastrointestinal Endoscopy Technology Status Evaluation Report recommended comparative studies of water-aided colonoscopy methods to refine the optimal insertion technique.
  
  
  OBJECTIVE
  Air insufflation (AI), water immersion (WI), and water exchange (WE) were compared head-to-head to test the hypothesis that WE produces the least insertion pain.
  
  
  METHODS
  Patient-blinded, prospective, randomized, controlled trials.
  
  
  METHODS
  Two community hospitals in Italy.
  
  
  METHODS
  First-time diagnostic or screening colonoscopy in unsedated patients with the option of on-demand sedation.
  
  
  METHODS
  Colonoscopy with AI, WI, or WE.
  
  
  METHODS
  Real-time maximum insertion pain (0 = none, 10 = worst). To avoid interventional bias, the timing of recording was at the discretion of the nurse assistant. Adjunct measures were implemented to ensure patient perception of minimal discomfort. Recalled pain and patients' guess of insertion methods were recorded after colonoscopy.
  
  
  RESULTS
  Results were merged for 576 randomized patients. Correct patient guesses lower than 33% confirmed adequate blinding. Significant correlation (Pearson coefficient 0.6, P < .0005) between real-time and recalled pain provided internal validation of the former as the primary outcome. Real-time pain (95% confidence interval [CI]: AI, 4.1 [3.7-4.5]; WI, 3.5 [3.0-3.9]; and WE, 2.5 [2.2-2.9] [P < .0005] was the lowest in the WE group. The proportions of patients completing unsedated colonoscopy based on the assigned methods were significantly different (WE, 74.7% vs WI, 62.4%; P = .009; vs AI, 65.3%; P = .04). WE required the least implementation of adjunct maneuvers.
  
  
  CONCLUSIONS
  Unblinded colonoscopists.
  
  
  CONCLUSIONS
  The current findings with an internally validated primary outcome in adequately blinded patients support the hypothesis that WE is superior to WI in attenuating real-time insertion pain and enhancing completion of unsedated colonoscopy.
authors.affiliation: Digestive Endoscopy Unit, S. Barbara Hospital, Iglesias, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Cadoni
authors.affiliation: Digestive Endoscopy Unit, N. S. di Bonaria Hospital, San Gavino Monreale, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Sanna
authors.affiliation: Digestive Endoscopy Unit, S. Barbara Hospital, Iglesias, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Gallittu
authors.affiliation: Digestive Endoscopy Unit, N. S. di Bonaria Hospital, San Gavino Monreale, Italy.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Argiolas
authors.affiliation: Digestive Endoscopy Unit, N. S. di Bonaria Hospital, San Gavino Monreale, Italy.
authors.forename: Viviana
authors.initials: V
authors.lastname: Fanari
authors.affiliation: Digestive Endoscopy Unit, N. S. di Bonaria Hospital, San Gavino Monreale, Italy.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Porcedda
authors.affiliation: Department of Surgical Sciences, University of Cagliari, Cagliari, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Erriu
authors.affiliation: Sepulveda Ambulatory Care Center, Veterans Affairs Greater Los Angeles Healthcare System, North Hills, California, USA; David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, California, USA.
authors.forename: Felix W
authors.initials: FW
authors.lastname: Leung
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003113:Colonoscopy / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D007327:Insufflation; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D010147:Pain Measurement; D017060:Patient Satisfaction; D011446:Prospective Studies; D016037:Single-Blind Method; D014867:Water; D055815:Young Adult
chemical_list: D014867:Water