The Optimal Timing of Carbon Dioxide Insufflation During Colonoscopy in Unsedated Patients

Study Overview
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Brief Summary
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Insufflation of carbon dioxide (CO2) instead of air can reduce pain resulting from colon distension after colonoscopy because CO2 is rapidly absorbed from the colon and excreted through the lungs. This reduces the effects of colonic distension and minimizes intracolonic gas at the end of the examination. The aims of the study were to evaluate the timing of administering CO2 insufflation and to identify predictors of discomfort for colonoscopy.

Official Title
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The Optimal Timing of Carbon Dioxide Insufflation During Colonoscopy in Unsedated Patients

Conditions
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Outpatients

Intervention / Treatment
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* Procedure: Insufflation with CO2


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients with an appropriate indication for colonoscopy were considered eligible. Exclusion Criteria: Exclusion criteria included severe hematochezia, acute colonic pseudo-obstruction, known obstructive lesions, age <18 years, prior colon resection, fulminant colitis, chronic obstructive pulmonary disease requiring oxygen, and a medical history of CO2 retention. Patients that required only a partial colonoscopy or were unable to read or understand Chinese were also excluded.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Insertion without CO2 insufflation<br>Patients were randomly allocated to receive whole procedure or extubation-only CO2 insufflation, using a randomized computer-generated list. | Procedure: Insufflation with CO2<br>* Patients were randomly allocated to receive whole procedure or extubation-only CO2 insufflation, using a randomized computer-generated list.<br>* Other names: the Olympus UCR Endoscopic CO2 Regulation Unit;|
| Experimental: Insertion with CO2<br>Patients were randomly allocated to receive whole procedure or extubation-only CO2 insufflation, using a randomized computer-generated list. | Procedure: Insufflation with CO2<br>* Patients were randomly allocated to receive whole procedure or extubation-only CO2 insufflation, using a randomized computer-generated list.<br>* Other names: the Olympus UCR Endoscopic CO2 Regulation Unit;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| abdominal pain during and after colonoscopy | Pain was recorded on a ten-point visual analog scale (0- no pain, 10- worst imaginable pain) at left-sided colonoscopic insertion, right-sided colonoscopic insertion, and at 1, 3, 6, and 24 hours postprocedure. | One day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| delayed bleeding |  | One day | 
| colonoscopic cecal intubation time |  | One day | 
| completeness of intubation |  | One day | 
| loop formation |  | One day |