title: Continuous fiberoptic PCO2 monitoring indicates poorer gastric perfusion during supraceliac aortic clamping than conventional gastric tonometry in humans: a pilot study.
abstract: OBJECTIVE
  To compare two monitors of gastric perfusion intraoperatively--continuous fiberoptic carbon dioxide partial pressure (PCO2) sensor and conventional gastric tonometer.
  
  
  METHODS
  Prospective, unblinded study.
  
  
  METHODS
  University teaching hospital.
  
  
  METHODS
  Adult patients undergoing major abdominal surgery.
  
  
  METHODS
  A fiberoptic probe (Biomedical Sensors, Pfizer, High Wycombe, England) capable of continuous PCO2 measurement and adapted to fit into the saline-filled balloon of a tonometric orogastric tube (Tonometrics, Instrumentarium Corp, Helsinki, Finland) was placed in the patients. The fiberoptic probe was attached to a Paratrend 7 machine (Biomedical Sensors, Pfizer) providing continuous intragastric PCO2 data. A second tonometric orogastric tube was passed and used according to the manufacturer's instructions, yielding intermittent PCO2 values.
  
  
  RESULTS
  Twelve patients provided 79 data pairs: 33 without aortic clamp, 23 infraceliac aortic clamp, and 23 supraceliac aortic clamp. Data are presented as mean +/- SD, and analysis of variance was used for comparison (p < 0.01); bias and precision were also calculated. Intramusosal PCO2 and PCO2 gradient were significantly higher, and intramucosal pH was significantly lower from continuous fiberoptic measurement in the supraceliac clamp group. In the no-clamp and infraceliac clamp groups, the differences between the 2 methods of measurement were not significant.
  
  
  CONCLUSIONS
  Conventional gastric tonometry overestimated perfusion during conditions of compromised gastric blood flow (supraceliac aortic clamp).
authors.affiliation: Department of Anesthesiology, University of California at Davis, USA.
authors.forename: A
authors.initials: A
authors.lastname: Melton
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood*; D002445:Celiac Artery / Q000502:physiology; D003250:Constriction; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008365:Manometry; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D012039:Regional Blood Flow / Q000502:physiology; D013270:Stomach / Q000098:blood supply*
chemical_list: D002245:Carbon Dioxide