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

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 (IAP_supine ) as well as 10° left lateral (IAP_lateral-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 IAP_supine was significantly higher than IAP_lateral-tilt (13.8 ± 2.4 vs 12 ± 2.3 mm Hg) (P < .001). The incidence of intraabdominal hypertension as per conventional definition, that is, IAP ≥12 mm 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 IAP_supine and IAP_lateral-tilt with various organ dysfunctions (P > .05). There was a significant correlation of intraabdominal hypertension when considering IAP_supine or IAP_lateral-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.