The Importance of Accurately Assessing Orthostatic Hypotension

Have the patient lie supine for 10 minutes and obtain blood pressure and HR. A preponderance of the literature reviewed used 5-10 minutes in the supine position as the baseline measurement. However, questions still remain regarding optimal baseline measurement, and further research is needed. Thus, the 10-minute supine time frame seems the best approach at this time.

Take blood pressure and HR immediately after the patient arises and ask about dizziness. The literature supports the idea that HR assessment will aid in differential diagnosis.^[6] HR increases 10-15 bpm normally on rising;^[23] in OH, HR may increase (with a concomitant fall in blood pressure) within a range of 15-30 bpm.^[1]

Grubb reported that, as patients arise, orthostatic stability usually takes place in less than 1 minute.^[24] It seems important to note any immediate fall in blood pressure and increase in HR because, even though the time interval to recovery is very small, an opportunity for mishap (eg, a fall) does exist. Kunert^[8] said the presence of symptoms, such as dizziness, might be more clinically important than a change in pressure reading. Further, among elderly patients, the baroreceptor response time may be blunted.^[1] Thus, although these patients may not be experiencing true OH, they may have a short period of dizziness and imbalance. (This situation presents an ideal teaching moment regarding fall prevention.)

After the patient maintains an upright posture for 3 minutes, obtain blood pressure and HR again. In the literature, standing times varied, but 2-3 minutes were the most common. Engstrom^[1] said, "If blood pressure is assessed for less than 2 minutes following postural change, the degree of hypotension may be overstated." However, taking into consideration individual variances (eg, age related) in physiological response times, the 3-minute time period would seem more accurate.