Are Standard Intra-Abdominal Pressure Values Different during Pregnancy?

Background: Measurement of intra-abdominal pressure (IAP) is an important parameter in the surveillance of intensive care unit patients. Standard values of IAP during pregnancy have not been well defined. The aim of this study was to assess IAP values in pregnant women before and after cesarean delivery. Methods: This prospective study, carried out from January to December 2011 in a French tertiary care centre, included women with an uneventful pregnancy undergoing elective cesarean delivery at term. IAP was measured through a Foley catheter inserted in the bladder under spinal anaesthesia before cesarean delivery, and every 30 minutes during the first two hours in the immediate postoperative period. Results: The study included 70 women. Mean IAP before cesarean delivery was 14.2 mmHg (95% CI: 6.3-23). This value was significantly higher than in the postoperative period: 11.5 mmHg (95% CI: 5-19.7) for the first measurement (p = 0.002). IAP did not significantly change during the following two postoperative hours (p = 0.2). Obese patients (n = 25) had a preoperative IAP value significantly higher than non-obese patients: 15.7 vs. 12.4; p = 0.02. Conclusion: In term pregnancies, IAP values are significantly higher before delivery than in the post-partum period, where IAP values remain elevated for at least two hours at the level of postoperative classical abdominal surgery. The knowledge of these physiological changes in IAP values may help prevent organ dysfunction/failure when abdominal compartment syndrome occurs after cesarean delivery.