How is an orthostatic (blood pressure) check performed to diagnose orthostatic hypotension?

Orthostatic Blood Pressure Measurement Technique

An orthostatic blood pressure check should be performed by measuring blood pressure after 5 minutes of rest in the sitting or lying position, followed by measurements at 1 minute and 3 minutes after standing, with orthostatic hypotension defined as a drop of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing. 1

Proper Technique for Orthostatic BP Assessment

Initial Preparation

• Ensure the patient is in a quiet environment with comfortable temperature (21-23°C)
• Use a validated blood pressure device with appropriate cuff size
• Place the BP cuff at heart level with the patient's back and arm supported

Step-by-Step Procedure

1. Baseline Measurement:

   • Have patient rest in sitting or lying position for 5 minutes
   • Measure BP and heart rate after this rest period
   • If using supine position, this may be more sensitive for detecting orthostatic hypotension 1

2. Standing Measurements:

   • Ask patient to stand up
   • Measure BP and heart rate at 1 minute after standing
   • Measure BP and heart rate again at 3 minutes after standing
   • Record any symptoms experienced during standing

3. Documentation:

   • Record all BP and heart rate values
   • Calculate the difference between baseline and standing measurements
   • Document any symptoms that occur during standing

Diagnostic Criteria

Orthostatic hypotension is diagnosed when there is:

• A decrease in systolic BP ≥20 mmHg, OR
• A decrease in diastolic BP ≥10 mmHg
• Within 3 minutes of standing 1

In patients with supine hypertension, a systolic BP drop ≥30 mmHg should be considered diagnostic 1.

Clinical Pearls and Pitfalls

Common Symptoms to Monitor

• Lightheadedness, dizziness
• Blurred vision
• Weakness, fatigue
• Neck and shoulder pain (coat hanger syndrome)
• Cognitive impairment 2

Important Considerations

• Orthostatic hypotension assessment should be performed at the initial visit for all patients and whenever concerning symptoms arise 1
• Heart rate response should be noted - blunted heart rate increase (<10 bpm) suggests neurogenic orthostatic hypotension 1
• Measurement after lying may be more sensitive for detecting orthostatic hypotension and better predicts falls, but sitting position may be more feasible in clinical practice 1
• Inter-arm BP differences should be assessed first; if systolic BP differs by >10 mmHg between arms, use the arm with higher readings for orthostatic assessment 1

Potential Confounding Factors

• Medications (especially antihypertensives)
• Time of day
• Food ingestion
• Ambient temperature
• Hydration status
• Physical deconditioning
• Standing after vigorous exercise 1

Alternative Testing Methods

If standard orthostatic vital signs are nondiagnostic but clinical suspicion remains high:

• Head-up tilt table testing at 60 degrees can be used as an alternative method 1
• Home BP monitoring with standing measurements may improve detection, as orthostatic hypotension is often more frequently detected at home (37.5%) than in clinic settings (15%) 3

By following this standardized approach to orthostatic blood pressure measurement, clinicians can accurately diagnose orthostatic hypotension and implement appropriate management strategies to reduce associated morbidity and mortality.