Orthostatic Hypotension: Stand Up and Be Diagnosed

We were taught in medical school to wait 3 minutes after a posture change to check orthostatic vital signs. Many patients with orthostatic hypotension experience symptoms immediately on standing. Why not measure blood pressure and pulse immediately to correlate with the symptoms?

- Scott E. Southworth, MD   Bountiful, Utah

Orthostatic hypotension has been defined as a reduction of systolic blood pressure (by at least 20 mm Hg) or of diastolic blood pressure (by at least 10 mm Hg) within 3 minutes of standing.¹ An acceptable alternative to standing is the demonstration of a similar drop in blood pressure within 3 minutes using a tilt table in the head-up position at an angle of at least 60 degrees.

Readings may be complicated by such variables as time of day, ingestion of food, ambient temperature, hypertension, medications, sex, and age--all of which can affect orthostatic blood pressure responses.¹ The orthostatic change should be sustained for at least 3 minutes to differentiate sluggish reflex responses, which are common in the elderly, from autonomic failure.²

In short, if a patient has symptoms immediately on standing that are accompanied by sustained orthostatic changes in blood pressure, orthostatic hypotension can be diagnosed.

- James R. Sowers, MD   Professor of Medicine and Physiology   Director, Division of Endocrinology, Metabolism, and Hypertension   Wayne State University School of Medicine   Detroit

References:

REFERENCES:

1.

Consensus statement on the definition of orthostatic hypotension, pure autonomic failure and multiple system atrophy.

Neurology

. 1996;46:1470.

2.

Kasper DL, Braunwald E, Fauci A, et al.

Harrison's Principles of Internal Medicine

. 16th ed. New York: McGraw-Hill; 2004.