Intraabdominal pressure and its relation with organ dysfunction in patients scheduled for elective cesarean section: Effect of supine vs left lateral tilt position.

Abstract

Intraabdominal pressure (IAP) is related to clinical outcome of patients. It is measured as intravesical pressure through a Foley catheter in the supine position. During pregnancy, there are data showing elevated IAP and also a suggestion that it may be a false increase due to pressure on the urinary bladder by the gravid uterus in the supine position. Additionally, it is not known whether the elevated IAP during pregnancy is merely a physiological change or is associated with impairment of organ functions. We thus aimed to establish a normal value of IAP in supine (IAPsupine ) as well as 10° left lateral (IAPlateral-tilt ) positions, and their association with organ functions as well as certain maternal risk characteristics. This prospective cross-sectional cohort study included 100 consenting parturients with term gestation posted for elective cesarean section under single-shot subarachnoid block. IAP was measured via an indwelling Foley catheter with a transducer connected to it, as per the recommended technique. Organ dysfunction was defined as Sequential Organ Failure Assessment (SOFA) subscore≥1 for the particular system. ctri.gov.in (CTRI/2017/11/010527). The IAPsupine was significantly higher than IAPlateral-tilt (13.8±2.4 vs 12±2.3mm Hg) (P<.001). The incidence of intraabdominal hypertension as per conventional definition, that is, IAP≥12mm Hg, was also higher in the supine position (77% vs 55%) (P<.001). None of the patients had dysfunction of the cardiovascular, renal or central nervous system. The incidence of respiratory, hepatic and hematologic dysfunction was 2%, 15% and 32%, respectively. Receiver operating characteristic analysis showed insignificant association of IAPsupine and IAPlateral-tilt with various organ dysfunctions (P>.05). There was a significant correlation of intraabdominal hypertension when considering IAPsupine or IAPlateral-tilt , with obesity (P=.004 and .000, respectively), as well as preeclampsia (P=.006 and .000, respectively). In nonlaboring patients undergoing elective cesarean section, IAP is significantly higher in the supine vs 10° left lateral position. In neither position is IAP significantly associated with organ dysfunction. Thus, the usual recommendation of a supine position for measuring IAP to diagnose intraabdominal hypertension, formulated consequent to its pathological effects on organ functions, may not be applicable to pregnant patients and needs urgent validation studies.