(Dr. Bell was one of the earliest physicians to recognize the importance of orthostatic intolerance and low blood volume in chronic fatigue syndrome -ed.)
A number of people have requested the procedure for orthostatic testing that we perform in the office. It takes about 45 minutes and requires a nurse to be constantly present. It is important to note that this test is difficult for some persons with CFS [Chronic Fatigue Syndrome] and an opportunity to rest for an hour after the testing is offered. Intravenous saline is helpful to aid recovery.
- Patients should be tested late morning or early afternoon with no unusual activity prior to testing. Large meals and large volumes of fluid prior to testing should be avoided
- Normal medications should be taken the day of the test. Medications, which affect circulating volume, should be stopped at least two weeks prior to testing, as they will affect the results. Examples are Florinef, diuretics, blood pressure medications, large salt loads. Tricyclics [antidepressants] and SSRI [selective serotonin reuptake inhibitor] medications are acceptable if not for research studies.
- Blood pressure should be taken with manual blood pressure cuff every three to five minutes, along with pulse. If available, a dynamap or other accurate BP [blood pressure] device can be used.
- Step 1. Patient lying down comfortably for 10 minutes. Pulse and BP are recorded at onset, 5 min and 10 min, along with recording of observations of spontaneously reported symptoms.
- Step 2. Patient stands without moving or leaning on any object for 30 min or as long as tolerated. If patient pre-syncopal, the test is terminated. Right arm is resting on table at mid chest (heart) level with BP cuff in place. Pulse and BP are taken every 5 minutes, and spontaneous symptoms recorded as well as observations (ie, yawning, feet mottled or bluish, etc). If symptoms become more severe, pulse and BP are taken every 3 minutes.
Below is a listing of the abnormalities observed and the normal values taken from Dr. David Streeten’s book Orthostatic Disorders of the Circulation.
Normal Test Results
- Systolic Blood Pressure (top number): recumbent: 100-142; Standing (4 min): 94-141; Orthostatic change: -19 to +11
- Diastolic Blood Pressure (bottom number): recumbent: 55-90; Standing: 61-97; Orthostatic change: -9 to +22
- Pulse: recumbent: 54-96; Standing: 62-108; Orthostatic change: -6 to +27
Indications of orthostatic intolerance
- Orthostatic systolic hypotension (low blood pressure): fall in systolic blood pressure of 20 mmHg or more
- Orthostatic diastolic hypotension (low blood pressure): fall in diastolic BP of 10 mm Hg or more.
- Orthostatic diastolic hypertension (high blood pressure): rise in diastolic BP to 98 mm Hg or higher
- Orthostatic narrowing of pulse pressure: reduction in pulse pressure to 18 mm Hg or lower.
- Orthostatic postural tachycardia (increased heart rate): increase in heart rate of 28 bpm or to greater than 110 b/min.