Automated blood pressure measurement devices: a potential source of morbidity in preeclampsia?

The purpose was to compare auscultatory and oscillometric techniques in the determination of maternal blood pressure in normotensive primigravid patients and primigravid patients with proteinuric preeclampsia (blood pressure > 140/90 on two occasions and proteinuria > 0.5 gm/L).

A prospective comparison of systolic and diastolic blood pressure was made with an automated device using oscillometric principles and two observers using a double-headed stethoscope to determine auscultatory observations (phase I and phase IV of the vascular sounds) in normotensive primigravid patients (N = 40) and primigravid patients with proteinuric hypertension (N = 17).

In patients with proteinuric preeclampsia the mean differences between auscultatory (phase I and phase IV) and oscillometric observations were 5.4 mm Hg (SEM 1.4 mm, p < 0.05) and 14.8 mm Hg (SEM 2.9 mm, p < 0.01) for systolic and diastolic observations, respectively. In normotensive patients the mean differences between auscultatory (phase I and phase IV) and oscillometric observations were 2.4 mm Hg (SEM 0.9 mm, p not significant) and 7.5 mm Hg (SEM 1.9 mm, p < 0.01) for systolic and diastolic observations, respectively.

Automated devices using oscillometric principles "underrecord" systolic and diastolic blood pressure compared with auscultatory observations (phase I and phase IV) in patients with proteinuric preeclampsia. In some cases the difference between observations exceeds 30 mm Hg.