Measurement of compartment pressure of the rectus sheath during intra-abdominal hypertension in rats

Objective To investigate whether the compartment pressure of the rectus sheath (CPRS) reflects the intra-abdominal pressure (IAP) under various conditions of intra-abdominal hypertension (IAH).Design and setting Prospective experimental study with in vivo pressure measurements at the Institute for Clinical and Experimental Surgery, University of Saarland.Animals Sprague-Dawley rats.Interventions Stepwise increase and decrease in IAP with continuous measurement of the correspondent CPRS.Measurements and results Physiological IAP (2 mmHg) and CPRS (6 mmHg) showed a statistically significant difference. Stepwise elevation in IAP was associated with a simultaneous increase in CPRS. Accordingly, stepwise decompression of IAP resulted in a stepwise decrease in CPRS. Under both conditions Bland-Altman analysis comparing IAP to correspondent CPRS showed a very good agreement for IAP at or above 12 mmHg. In addition, closure of the overlaying subcutaneous tissue and skin did not affect CPRS or its correlation with IAP.Conclusions CPRS accurately reflects IAP for IAP of 12 mmHg or higher. Thus CPRS measurements may represent a novel approach for diagnosis and monitoring of IAH.Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.