Clinical Trial: Comparison of Methods to Distend the Colon During Insertion: CO2, Air Insufflation, Water-aided Colonoscopy

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Comparison of Methods for Luminal Distention for on Demand Sedation Colonoscopy: Air Insufflation, Carbon Dioxide and Water-aided Colonoscopy. A Randomized Controlled Trial.

Brief Summary:

Insufflation of the colon, usually with room air, is necessary to distend the lumen for exploration. Carbon dioxide (CO2) insufflation instead of room air insufflation (AI) has been shown to decrease symptoms of abdominal pain or discomfort during the procedure and particularly during the following 24 hours. CO2 is is rapidly absorbed by the intestinal mucosa and exhaled through respiration. AI colonoscopy has usually been the reference standard to compare colonoscopy using CO2 insufflation. In two recent articles AI was compared to either CO2 insufflation and Water-aided colonoscopy (WAC), which entails infusion of water to facilitate insertion to the cecum.

WAC can be categorized broadly in Water Immersion (WI) and Water Exchange (WE). In WI water is infused during the insertion phase of colonoscopy, with removal of infused water predominantly during withdrawal. Occasional use of insufflation may be allowed. WE entails complete exclusion of insufflation, removal of residual colonic air pockets and feces, and suction of infused water predominantly during insertion to minimize distention. During the withdrawal phase insufflation is used to distend the colonic lumen.

In the WAC arms of the two mentioned articles the insertion method used was WI, with infusion of water at room temperature or at 37°C. During withdrawal, air insufflation or either air or CO2 insufflation were employed.

Compared to AI, CO2 insufflation and WI (using room air insufflation or CO2 insufflation during withdrawal) were effective in both studies in decreasing sedation requirement, pain and tolerance scores, with patients' higher willingness to repeat the procedure.

Until now no direct comparison has been made within a single study about pain score

Detailed Summary:

Design: Prospective double blinded two-center randomized controlled trial. Methods: Colonoscopy with air insufflation, CO2, Water Immersion/CO2, Water Exchange/CO2, Water Immersion/AI and Water Exchange/AI to aid insertion of colonoscope; split dose bowel preparation; on demand-sedation.

Control method: Air insufflation colonoscopy. Study methods: CO2 colonoscopy, Water Immersion/CO2 colonoscopy, Water Exchange/CO2 colonoscopy, Water Immersion/AI colonoscopy, Water Exchange/AI colonoscopy.

Population: Consecutive 18 to 85 year-old diagnostic in-patients and outpatients. After informed consent, assignment to control or study arms based on computer generated randomization list with block allocation and stratification.

Primary outcome: Maximum pain score recorded during colonoscopy. Secondary outcomes: Cecal intubation rate and time, total procedure time (including biopsy and/or polypectomy), need for sedation and its dosage, overall pain score at discharge. In addition, Adenoma Detection Rate, Mean Adenomas per Procedure, position changes, amount of infused and suctioned water during insertion and withdrawal will be recorded. Bloating after examination and at discharge and patient willingness to repeat the examination will be evaluated.


Sponsor: Presidio Ospedaliero Santa Barbara

Current Primary Outcome: Maximum pain score recorded during colonoscopy. [ Time Frame: 1 hour ]

Pain assessed using a visual analogue scale (VAS) with a score 0=absence of pain, 2=simply "discomfort", 10=the worst possible pain. Before the procedure, an endoscopic nurse will explain the VAS scoring system to the patients. Every 60 seconds during colonoscopy patients will be asked about discomfort or pain. The responses will be recorded, and the maximum pain score noted.


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Overall pain after the procedure. [ Time Frame: 1 hour. ]
    After the procedure and at discharge from the Endoscopy Unit, an assistant nurse blinded to the procedure will ask patients about overall pain using the same VAS when neither the endoscopist nor the assistant nurse who performed the colonoscopy will be present. Patients will be asked to quantify the degree of pain experienced and to place a mark over the VAS accordingly.
  • Cecal intubation rate. [ Time Frame: 1 hour ]
    Cecal intubation will be defined as passage of the tip of the colonoscope beyond the ileocecal valve so that the medial wall of the cecum proximal to the ileocecal valve will be observed.
  • Cecal intubation time. [ Time Frame: 1 hour. ]
    Cecal intubation time will be defined as the time for passage of the colonoscope from the rectum to the cecum.
  • Total procedure time. [ Time Frame: 1 hour. ]
    Total procedure time (including time required for polyp resection or biopsy).
  • Adenoma detection rate. [ Time Frame: 15 months. ]
    Proportion of subjects with at least one adenoma of any size.
  • Mean adenomas per procedure. [ Time Frame: 15 months. ]
    Total number of adenomas resected per subject.
  • Advanced adenomas. [ Time Frame: 15 months. ]
    Total number of advanced adenomas: diameter ≥10mm, or high grade dysplasia, or with ≥20% villous components.


Original Secondary Outcome: Same as current

Information By: Presidio Ospedaliero Santa Barbara

Dates:
Date Received: September 27, 2013
Date Started: October 2013
Date Completion:
Last Updated: July 30, 2014
Last Verified: July 2014