title: A retrospective analysis of cecal barotrauma caused by colonoscope air flow and pressure.
abstract: BACKGROUND
  This study addressed the question of whether barotrauma during colonoscopy is sufficient to rupture the colon.
  
  
  METHODS
  A total of 3000 colonoscopies were retrospectively analyzed, and the colonoscopes used for these procedures were evaluated in an in vitro analysis. Air pressure at the tip of the colonoscopes and air flow through the instruments were measured. The equation F=F MAX-P TIP/R was used to graph flow values (F) from the maximum measured flow (F MAX), the calculated resistance to air flow offered by the colonoscope (R), and the air pressure observed at the colonoscope tip (P TIP ).
  
  
  RESULTS
  Four perforations occurred during 1500 consecutive colonoscopies performed with equipment from one manufacturer (Pentax Precision Instrument Corp., Orangeburg, NY) whereas, no perforation occurred during 1500 consecutive colonoscopies performed with equipment from another manufacturer (Olympus America Corp., Melville, NY) ( p < or =0.06). The Pentax colonoscopes used in patients with barotrauma-induced cecal perforations insufflated air at a rate greater than 1.46 L/m at 80 mmHg intraluminal pressure. Olympus colonoscopes did not. In vitro maximum air-flow rates of 2 L/m at a tip pressure of 0 mm Hg separated the Pentax from the Olympus instruments ( p <0.022). Conclusions Colonoscopes with maximum flow rates of less than 2 L/m at 0 mmHg tip pressure have insufficient flow capacity to generate flows above 1.46 L/m at 80 mmHg intraluminal pressure and thus may protect patients from cecal barotrauma.
authors.affiliation: Medical Center of Independence, Missouri, GI Laboratory, St. Mary's Hospital, Blue Springs, MO 64014, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Woltjen
mesh_terms: D000328:Adult; D000368:Aged; D000392:Air Movements; D000399:Air Pressure; D000465:Algorithms; D001469:Barotrauma / Q000209:etiology*; D002432:Cecum / Q000293:injuries*; D020685:Colonoscopes / Q000009:adverse effects*; D004867:Equipment Design; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012421:Rupture / Q000209:etiology