From the Guidelines
Orthostatic vital signs should be performed when evaluating patients with suspected volume depletion, unexplained syncope or near-syncope, dizziness upon standing, or autonomic dysfunction, as well as before starting or intensifying BP-lowering medication, especially in elderly patients or those with conditions that may affect autonomic function 1. The procedure involves measuring blood pressure and heart rate with the patient in three positions: lying supine for 5 minutes, immediately upon standing, and again after standing for 3 minutes. A positive orthostatic test is indicated by a drop in systolic blood pressure of at least 20 mmHg or diastolic pressure of at least 10 mmHg, or an increase in heart rate of 30 beats per minute or more upon standing, as defined in the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1. These measurements are particularly important in:
- Elderly patients
- Those taking medications that can cause hypotension (such as antihypertensives, diuretics, antidepressants, or antipsychotics)
- Patients with dehydration, blood loss, or prolonged bed rest
- Those with conditions like Parkinson's disease or diabetes that may affect autonomic function The physiological basis for orthostatic changes is that normally upon standing, blood pools in the lower extremities, triggering compensatory mechanisms to maintain cerebral perfusion; when these mechanisms fail, orthostatic hypotension results, potentially causing symptoms like lightheadedness, weakness, or syncope. It is recommended to test for orthostatic hypotension before starting or intensifying BP-lowering medication, by first having the patient sit or lie for 5 min and then measuring BP 1 and/or 3 min after standing 1. In patients with supine hypertension, it is recommended to pursue non-pharmacological approaches as the first-line treatment of orthostatic hypotension and to switch BP-lowering medications that worsen orthostatic hypotension to an alternative BP-lowering therapy 1.
From the FDA Drug Label
The potential for supine and sitting hypertension should be evaluated at the beginning of midodrine therapy. There is no direct information in the provided drug labels about when to perform orthostatic vital signs. The FDA drug label does not answer the question.
From the Research
Orthostatic Vital Signs
- Orthostatic vital signs (OVS) are useful in selected patients with frequent emergency department (ED) presentations, such as blood loss, dehydration, dizziness, weakness, and falls 2
- The indications for OVS measurement, performance, and interpretation can be controversial, but they are useful for detecting hypovolemia and orthostatic hypotension 2
- A rapid measurement protocol, including a 1-min interval after standing, is supported by available evidence 2
Patient Selection
- OVS are useful in patients with symptoms such as dizziness, weakness, and falls, particularly in the elderly 2, 3, 4
- Patients taking certain medications, such as antidepressants, may be at higher risk of orthostatic hypotension and may benefit from OVS measurement 4
- Patients with autonomic failure or neurocardiogenic syncope may also benefit from OVS measurement 5