title: Carbon dioxide insufflation during ERCP for reduction of postprocedure pain: a randomized, double-blind, controlled trial.
abstract: BACKGROUND
  Abdominal pain after ERCP is common, and although it is frequently nonspecific and self-limited, it may provoke concern for complications and thus distress both patients and physicians. Carbon dioxide (CO(2)) insufflation during ERCP may reduce abdominal distension in comparison to insufflation of air, resulting in less pain.
  
  
  OBJECTIVE
  To compare the incidence and severity of post-ERCP pain in patients receiving CO(2) versus air insufflation during ERCP.
  
  
  METHODS
  Randomized, double-blind, controlled trial.
  
  
  METHODS
  University medical center.
  
  
  METHODS
  This study involved consecutive patients presenting for ERCP, excluding those with significant preprocedure pain or obstructive lung disease.
  
  
  METHODS
  Randomization to insufflation with air or CO(2); all other care was identical.
  
  
  METHODS
  Pre-ERCP and post-ERCP pain and nausea were assessed by using a 0 to 10 visual analogue scale. Patient waist circumferences were measured before and after procedures.
  
  
  RESULTS
  One hundred patients (82 outpatients, 51 women, mean age 54.4 years, 50 randomized to CO(2)) completed the study. The CO(2) and air groups were similar in regard to demographics, indication for ERCP, and procedure duration. The mean pain score 1 hour post-ERCP was higher with air than with CO(2) insufflation (1.9 vs 0.7, P = .01). Similarly, the incidence of any pain at 1 hour post-ERCP was higher with air than with CO(2) (48% vs 28%, P = .04). The mean increase in waist circumference was greater with air than with CO(2) (2.1 cm vs 0.3 cm, P = .003). Adverse events were infrequent and did not differ by group. No serious cardiopulmonary complications occurred.
  
  
  CONCLUSIONS
  Single-center, selected patient population.
  
  
  CONCLUSIONS
  Insufflation of CO(2) during ERCP reduces postprocedure pain and abdominal distension in comparison to insufflation of air. The use of CO(2) in deeply sedated, prone patients appears to be safe.
authors.affiliation: Division of Digestive Diseases and Nutrition, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73117, USA. john-maple@ouhsc.edu
authors.forename: John T
authors.initials: JT
authors.lastname: Maple
authors.forename: Rajesh N
authors.initials: RN
authors.lastname: Keswani
authors.forename: R Mark
authors.initials: RM
authors.lastname: Hovis
authors.forename: Esmat Z
authors.initials: EZ
authors.lastname: Saddedin
authors.forename: Sreenivasa
authors.initials: S
authors.lastname: Jonnalagadda
authors.forename: Riad R
authors.initials: RR
authors.lastname: Azar
authors.forename: Clint
authors.initials: C
authors.lastname: Hagen
authors.forename: David M
authors.initials: DM
authors.lastname: Thompson
authors.forename: Lawrence
authors.initials: L
authors.lastname: Waldbaum
authors.forename: Steven A
authors.initials: SA
authors.lastname: Edmundowicz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002245:Carbon Dioxide / Q000008:administration & dosage*; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007327:Insufflation; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000517:prevention & control*; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide