What should be done for a patient who experiences dizziness and lethargy when standing up, suspected of having orthostatic hypotension?

Management of Orthostatic Hypotension with Lethargy and Pallor on Standing

Immediately have the patient lie down or sit to restore cerebral perfusion, then measure orthostatic vital signs after 5 minutes supine and at 1 and 3 minutes after standing to confirm orthostatic hypotension (≥20 mmHg systolic or ≥10 mmHg diastolic drop). 1

Immediate Actions

• Position the patient supine or seated immediately to relieve symptoms and prevent syncope or falls 2
• Measure blood pressure and heart rate after 5 minutes lying down, then at 1 minute and 3 minutes after standing 1
• Orthostatic hypotension is confirmed by a sustained drop of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing 2, 1
• In patients with baseline supine hypertension, use a threshold of ≥30 mmHg systolic drop 1

Critical Diagnostic Distinction

Assess the heart rate response to differentiate neurogenic from non-neurogenic causes:

• Neurogenic orthostatic hypotension: Heart rate increase <15 bpm upon standing, indicating autonomic nervous system dysfunction 1, 3
• Non-neurogenic orthostatic hypotension: Heart rate increase ≥15 bpm, suggesting medications, dehydration, blood loss, or cardiac dysfunction 3

This distinction is critical because neurogenic forms require more aggressive pharmacologic management and carry risk of supine hypertension 3

Essential History Elements

Ask specifically about:

• Symptom characterization: Lightheadedness, dizziness, visual disturbances (blurring, tunnel vision, loss of vision), weakness, fatigue, pallor, sweating, nausea 2, 1
• Timing: When symptoms occur, duration of standing before symptoms develop 1
• Precipitating factors: Meals (postprandial hypotension), warm environments, exertion 2
• Medication review: Alpha-blockers, sedatives, prostate medications, antihypertensives, diuretics, nitrates 2, 1
• Associated conditions: Diabetes, Parkinson's disease, recent infections, deconditioning 2

Initial Workup

• Obtain a 12-lead ECG in all patients to detect arrhythmias, conduction abnormalities, or structural heart disease 1
• Order laboratory studies only if clinically indicated based on history and examination (not routinely) 1
• Consider cardiac causes: Pulmonary embolism is frequently underdiagnosed in patients with syncope 2

Immediate Management Algorithm

Step 1: Review and Adjust Medications

Discontinue or reduce medications that worsen orthostatic hypotension, prioritizing:

• Alpha-blockers 1
• Sedatives 1
• Prostate-specific medications 1
• Unnecessary blood pressure-lowering drugs 1
• Diuretics and nitrates may further aggravate orthostatic hypotension 2

Step 2: Implement Nonpharmacologic Interventions

All patients should receive these interventions:

• Increase fluid intake to 2-3 liters daily 3
• Avoid large meals that worsen postprandial hypotension 3
• Limit or avoid alcohol 3
• Teach acute physical counterpressure maneuvers to raise blood pressure when symptoms occur: leg crossing, squatting, arm tensing, bending forward at the waist 1, 3

Step 3: Pharmacologic Treatment (if symptoms persist)

Midodrine is the preferred first-line pharmacologic agent for symptomatic orthostatic hypotension that persists despite nonpharmacologic interventions 3, 4

• Midodrine increases standing systolic blood pressure by approximately 15-30 mmHg at 1 hour after a 10 mg dose 4
• Typical dosing: 10 mg three times daily, with the last dose not later than 6 PM 4
• The goal is to improve symptoms and functional capacity, not to achieve arbitrary blood pressure targets 3

Critical Pitfalls to Avoid

Supine Hypertension

• Monitor for supine hypertension in patients with autonomic failure, as it can lead to left ventricular hypertrophy, coronary disease, flash pulmonary edema, heart failure, renal failure, stroke, and sudden death 3
• Midodrine can cause marked elevation of supine blood pressure (>200 mmHg systolic) 4
• Measure supine and standing blood pressures at each visit to assess treatment response and detect supine hypertension 3

Elderly-Specific Considerations

• Orthostatic hypotension carries a 64% increase in age-adjusted mortality and increased risk of falls and fractures 2
• Obtain lying and standing blood pressures periodically in all hypertensive individuals over 50 years old 2
• Delayed orthostatic hypotension (occurring >3 minutes after standing) is common in elderly persons due to stiffer hearts and impaired compensatory vasoconstrictor reflexes 2

Alternative Diagnoses to Consider

• Vasovagal syncope: Blood pressure drop starts several minutes after standing with accelerating rate of drop, short-lived low blood pressure 2
• Classical orthostatic hypotension: Blood pressure drop starts immediately on standing with decelerating rate of drop, sustained low blood pressure for many minutes 2
• POTS (Postural Orthostatic Tachycardia Syndrome): Heart rate increase >30 bpm (or >120 bpm) within 10 minutes of standing without orthostatic hypotension, mostly in young women 2