Intra-abdominal pressure measurement: validation of intragastric pressure as a measure of intra-abdominal pressure

Background: The diagnosis of abdominal compartment syndrome depends uponthe demonstration of an elevated intra-abdominal pressure (IAP).Direct measures of IAP are impractical in the critical careunit; intravesical pressure (IVP) and intragastric pressure(IGP) should represent acceptable surrogate measures. IVP isthe preferred measure of IAP in critical care. We consideredthat IGP represents a practical alternative. The objective ofthis preliminary study was to observe the relationship betweenIGP and IAP. Methods: After Institutional Ethics Board approval, 29 patients havingelective laparoscopic surgery were recruited. IAP was measureddirectly via the abdominal trochar. This was compared with IGPmeasured via a commercial balloon catheter placed into the stomach. Results: Measured IGP was always more positive than IAP; both showedlinear correlation (r²>0.9). When IGP was calibrated againstIAP, an estimated difference between the IGP and IAP of ±2.5 mm Hg for 95% of the measurements was seen. Conclusions: The study demonstrates the strength of the relationship betweenIGP and IAP in normal individuals. Application of IGP measurementin the critical care patient is necessary to demonstrate itssuitability for continuous IAP assessment.