Assessment of postural hypotension in elderly patients.

Change in blood pressure on standing was measured in 23 geriatric inpatients during the morning. The fall in systolic blood pressure was found to be greatest 30 s after standing, at 9.3 +/- 3.3 (SEM) mmHg and had returned to the supine levels within 2 min. In contrast, the diastolic pressure rose to a maximum of 9.7 +/- 1.8 mmHg by 2 min. In 13 patients the measurements were repeated in the afternoon after lunch. The systolic blood pressure drop was significantly greater: 20.8 +/- 3.6 against 7.1 +/- 2.0 mmHg in the morning (p = 0.01). Standardization of the time after standing and time of day of measurement may allow more precise comparisons of different studies.