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.
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
Consensus statement on the definition of orthostatic hypotension, pure autonomic failure and multiple system atrophy.
Kasper DL, Braunwald E, Fauci A, et al.
Harrison's Principles of Internal Medicine
. 16th ed. New York: McGraw-Hill; 2004.