The comparison of non-invasive blood pressure monitoring with brachial intra-arterial blood pressure monitoring in patients with severe pre-eclampsia

[摘要] ENGLISH ABSTRACT: OBJECTIVE: The aim of this study was to compare the accuracy of non-invasivebrachial blood pressure measurements, using automated and manual devices, toinvasive brachial intra-arterial blood pressure measurements in patients with preeclampsia,during acute severe hypertension.STUDY DESIGN: A prospective descriptive cross sectional study was conducted inthe Obstetrics Critical Care Unit (OCCU) of Tygerberg Hospital. Pre-eclampticpatients with acute severe hypertension, who required the placement of brachialintra-arterial lines due to failed radial intra-arterial line placement, were included inthe study. Both automated oscillometric and blinded manual aneroidsphygmomanometric blood pressures were recorded during hypertensive peaks andafter stabilization of BP using intravenous Labetalol or Nepresol. These two noninvasivemethods of blood pressure measurements were compared to brachial intraarterialblood pressure measurements.RESULTS:There was weak correlation between manual and intra-arterial SBP (r = 0.27, p =0.048) for SBP≥160mmHg. The calculated mean difference between manual SBPcompared to the intra-arterial SBP in this group was -23.19mmHg (+/- 19.40). Therewas moderate correlation between automated and intra-arterial SBP (r = 0.69, p <0.05). The calculated mean difference between automated SBP compared to theintra-arterial SBP in this group was -16.85mmHg (+/- 11.58).CONCLUSION:This study of pre-eclamptic women demonstrated that both non-invasive methods ofBP measurement were inaccurate measures of the true systolic intra-arterial BP andsignificantly underestimated SBP≥160mmHg when compared to brachial intra-arterial measurements. The SBP was also underestimated, to a lesser degree, for mildmoderate hypertension.This study also demonstrated that direct invasive BP monitoring using the brachialartery is a safe method for accurate haemodynamic monitoring.We recommend the use of intra-arterial BP monitoring in pre-eclamptic women withacute severe hypertension. Radial arterial cannulation should be used as the firstoption and the brachial artery should be used if the first option fails.

[发布机构] Stellenbosch University