BACKGROUND: Noninvasive monitoring of intra-abdominal pressure (IAP) by measuring abdominal wall tension (AWT) was effective and feasible in previous postmortem and animal studies. This study aimed to investigate the feasibility of the AWT method for noninvasively monitoring IAP in the intensive care unit (ICU). METHODS:In this prospective study, we observed patients with detained urethral catheters in the ICU of Shanghai Tenth People's Hospital between April 2011 and March 2013. The correlation between AWT and urinary bladder pressure (UBP) was analyzed by linear regression analysis. The effects of respiratory and body position on AWT were evaluated using the paired samples t test, whereas the effects of gender and body mass index (BMI) on baseline AWT (IAP<12 mmHg) were assessed using one-way analysis of variance. RESULTS:A total of 51 patients were studied. A significant linear correlation was observed between AWT and UBP (R=0.986, P<0.01); the regression equation was Y=-1.369+9.57X (P<0.01). There were signifi cant differences among the different respiratory phases and body positions (P<0.01). However, gender and BMI had no signifi cant effects on baseline AWT (P=0.457 and 0.313, respectively). CONCLUSIONS:There was a signifi cant linear correlation between AWT and UBP and respiratory phase, whereas body position had signifi cant effects on AWT but gender and BMI did not. Therefore, AWT could serve as a simple, rapid, accurate, and important method to monitor IAP in critically ill patients.