Continuous fiberoptic PCO2 monitoring indicates poorer gastric perfusion during supraceliac aortic clamping than conventional gastric tonometry in humans: a pilot study.

摘要

OBJECTIVE: To compare two monitors of gastric perfusion intraoperatively--continuous fiberoptic carbon dioxide partial pressure (PCO2) sensor and conventional gastric tonometer. DESIGN: Prospective, unblinded study. SETTING: University teaching hospital. PARTICIPANTS: Adult patients undergoing major abdominal surgery. INTERVENTIONS: 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. MEASUREMENTS AND MAIN 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. CONCLUSION: Conventional gastric tonometry overestimated perfusion during conditions of compromised gastric blood flow (supraceliac aortic clamp).