Diagnosing orthostatic hypotension with continuous and interval blood pressure measurement devices.

Orthostatic hypotension (OH) is defined as a drop in systolic blood pressure (SBP) of ≥20 mm Hg and/or a drop in diastolic blood pressure (DBP) of ≥10 mm Hg within 3 min of standing. The international guidelines recommend ideally diagnosing OH with a continuous blood pressure (BP) measurement device, although in daily practice interval BP measurement devices are used more often. We aimed to investigate the difference in observed prevalence of OH between an interval and a continuous BP measurement device. A total of 104 patients with a mean age of 69 years were included. The prevalence of OH was 35.6% (95% CI: 26.4-44.8) with the interval BP measurement and 45.2% (95% CI: 35.6-54.8) with the continuous BP measurement device (P = .121). Lin's coefficient of concordance ranged from 0.47 to 0.59 for the drop in systolic blood pressure and from 0.33 to 0.42 for the drop in diastolic blood pressure. The positive proportion of agreement in diagnosis of OH between the interval and continuous measure was 59.5% and the negative proportion of agreement was 72.5%. Although the prevalence of OH was not significantly different between the continuous and the interval BP measurement devices using a similar amount of measurement, the concordance between interval and continuous measure is low resulting in low positive and negative proportions of agreement in the diagnosis of OH. We conclude that continuous BP measurement cannot be substituted by an interval BP measurement to diagnose OH.

Standing orthostatic blood pressure measurements cannot be replaced by sitting measurements.

As many elderly patients are not able to stand for several minutes, sitting orthostatic blood pressure (BP) measurements are sometimes used as an alternative. We aimed to investigate the difference in BP response and orthostatic hypotension (OH) prevalence between the standard postural change to the sitting and the standing position in a cross-sectional observational study. BP was measured with a continuous BP measurement device during two postural changes, from supine to the sitting and from supine to the standing position. Linear mixed models were used to investigate the differences in changes (Δ) of systolic BP (SBP) and diastolic BP (DBP) between the two postural changes. The prevalence and the positive and negative proportions of agreement of OH were calculated of the two postural changes. One hundred and four patients with a mean age of 69 years were included. ΔSBP was significantly larger in the standing position compared with the sitting between 0 and 44 s. ΔDBP was significantly larger in the sitting position compared with the standing 75-224 s after postural change. The prevalence of OH was 66.3% (95% confidence interval (CI) 57.2, 75.4) in the standing position and 67.3% (95% CI 58.3, 76.3) in the sitting position. The positive proportion of agreement was 74.8% and the negative proportion of agreement was 49.3%. A clear difference was seen in BP response between the two postural changes. Although no significant difference in prevalence of OH was observed, the positive and negative proportion of agreement of the prevalence of OH were poor to moderate, which indicates a different outcome between both postural changes.