title: Patient-controlled room air insufflation versus automated carbon dioxide delivery for CT colonography.
abstract: OBJECTIVE
  Our objective was to prospectively compare colonic distention and patient comfort at screening CT colonography (CTC) with patient-controlled room air (RA) insufflation versus automated carbon dioxide (CO2) delivery.
  
  
  METHODS
  Two hundred eight adults undergoing CTC were randomized to RA or CO2 (104 per method). Colonic distention was prospectively assessed by segment using a 4-point scale (1 = optimal, 2 = adequate, 3 = inadequate, 4 = collapsed). Adequacy of combined supine/prone segmental evaluation was also recorded. Patients provided discomfort ratings on a 0-10 scale (0-1 = none/insignificant, 2-3 = minimal, 4-6 = intermediate, 7-10 = significant) before, during, and after the procedure.
  
  
  RESULTS
  No significant differences in segmental distention were observed in the prone position between techniques. In the supine position, CO2 resulted in significantly greater distention in the sigmoid, descending, and transverse segments (p < 0.01). After combined supine/prone assessment, two/104 (1.9%) and three/104 (2.9%) patients were judged to have an inadequately evaluated segment on RA and CO2, respectively (four sigmoid, one transverse). Mean discomfort scores for RA and CO2 were 3.97 and 5.08 during the examination (p < 0.01); 0.91 and 0.42 immediately after (p < 0.01); 0.51 and 0.25 15 min later (p < 0.05); and 0.15 and 0.04 2 hours later (p < 0.01), respectively. During active distention, 19 (18.3%) and 33 (31.7%) patients reported significant transient discomfort with RA and CO2, respectively (p < 0.05). Beyond 15 min, only two (1.9%) patients with RA and no patients with CO2 had a discomfort level higher than 3.
  
  
  CONCLUSIONS
  Although patient-controlled RA insufflation and automated CO2 delivery each resulted in negligible postprocedure discomfort and reliable colonic distention, CO2 was better for both categories.
authors.affiliation: Department of Radiology, University of Wisconsin Medical School, Clinical Science Center, 600 Highland Ave., Madison, WI 53792, USA.
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Shinners
authors.forename: Perry J
authors.initials: PJ
authors.lastname: Pickhardt
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Taylor
authors.forename: Debra A
authors.initials: DA
authors.lastname: Jones
authors.forename: Cara H
authors.initials: CH
authors.lastname: Olsen
mesh_terms: D000388:Air; D002245:Carbon Dioxide / Q000008:administration & dosage*; D023881:Colonography, Computed Tomographic / Q000379:methods*; D005260:Female; D006801:Humans; D007327:Insufflation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D002245:Carbon Dioxide