P 49 Brachial artery invasive versus non-invasive blood pressure monitoring in women with severe pre-eclampsia

Abstract

Objective The aim of this study was to compare the accuracy of non-invasive blood pressure measurements in the brachial artery based on systolic occlusion pressures to brachial intra-arterial blood pressure measurements in patients with severe pre-eclampsia. Methods A prospective descriptive cross sectional study was conducted in the Obstetrics Critical Care Unit (OCCU) of Tygerberg Hospital. In this unit when it was not technically possible to cannulate the radial artery for intra-arterial blood pressure monitoring, the clinician cannulised the brachial artery. This study prospectively enrolled 15 women with severe pre-ecalmpsia and an intra-arterial brachial artery cannula in situ. Simultaneous monitoring was performed using both automated oscillometric and manual aneroid sphygmomanometric blood pressures. These two non-invasive methods of blood pressure measurements were compared to brachial intra-arterial blood pressure measurements.The University Ethics Committee approved the study protocol. The paired T-test was used to compare measured values. Results There was weak correlation between manual and intra-arterial SBP ( r = 0.27, p = 0.048) for SBP ⩾ 160 mmHg. The calculated mean difference between manual SBP compared to the intra-arterial SBP in this group was −23.19 mmHg (±19.40). There was moderate correlation between automated and intra-arterial SBP ( r = 0.69, p r = 0.53, p Conclusion When compared to intra-arterial monitoring in the brachial artery, compared to the systolic occlusion pressures in the brachial artery measured with the automated and manual methods it showed poor correlation with systolic severe hypertension values. Intra-arterial blood pressure monitoring is best at detection of systolic peaks in patients with severe-pre-eclampsia.