How to manage orthostatic hypotension diagnosed by a tilt table test?

Management of Orthostatic Hypotension Diagnosed by Tilt Table Test

The primary management of orthostatic hypotension diagnosed by tilt table test should focus on discontinuing or modifying causative medications, increasing fluid and salt intake, using compression garments, and implementing physical countermeasures, with pharmacologic therapy reserved for patients who do not respond to these initial measures. 1

Initial Assessment and Classification

• Determine the type of orthostatic hypotension:
  • Neurogenic (inadequate sympathetic response, minimal heart rate increase)
  • Non-neurogenic (medication-induced, hypovolemia, deconditioning)
• Assess for common symptoms: dizziness, lightheadedness, blurred vision, weakness, fatigue, syncope
• Identify high-risk patients (commercial vehicle drivers, machine operators, pilots) who require more aggressive management 1

First-Line Management Strategies

1. Medication Review and Modification:

   • Discontinue or reduce doses of hypotensive medications 1
   • Common culprits: diuretics, vasodilators, antidepressants, antipsychotics
   • Alcohol should be avoided as it worsens orthostatic intolerance 1

2. Non-Pharmacologic Interventions (Class I recommendations):

   • Volume expansion:
     • Increase salt intake (8-10g daily)
     • Increase fluid intake (2-3 liters daily)
   • Physical countermeasures:
     • Compression garments for lower extremities
     • Elevate head of bed 10° during sleep
     • Avoid prolonged standing
     • Protected posture (sitting rather than standing when possible)
   • Postural training:
     • Gradual exercise program to improve conditioning
     • Tilt training for patients with vasovagal syncope 1

3. Situational Modifications:

   • Identify and avoid specific triggers when possible
   • For unavoidable triggers (e.g., micturition, defecation):
     • Maintain central volume
     • Use protected postures
     • Perform physical counter-maneuvers 1

Pharmacologic Management

For patients who do not respond adequately to non-pharmacologic measures:

1. First-line medications:

   • Midodrine (alpha-1 agonist):
     • Dosage: Start with 2.5 mg and titrate up to 10 mg three times daily
     • Take last dose at least 3-4 hours before bedtime to avoid supine hypertension
     • Monitor for supine hypertension, urinary retention, and bradycardia
     • Contraindicated in patients with severe cardiac disease, acute renal failure, urinary retention, pheochromocytoma, or thyrotoxicosis 2, 3

2. Second-line medications:

   • Fludrocortisone:
     • Volume expansion through sodium retention
     • Monitor for supine hypertension, edema, hypokalemia
     • Use cautiously in patients with heart failure or renal impairment 1, 3

3. Other pharmacologic options:

   • Vasoconstrictors and salt supplements (but monitor for supine hypertension) 1
   • Pyridostigmine for neurogenic orthostatic hypotension 4

Special Considerations

• Paradoxical effects: Adding salt to water may actually attenuate the acute pressor response compared to water alone 5
• Supine hypertension: Common complication of treatment that requires careful monitoring
  • Prevent by sleeping with head of bed elevated
  • Take last dose of medications several hours before bedtime 2
• Elderly patients: More susceptible to orthostatic hypotension due to age-related baroreceptor sensitivity decline and polypharmacy 6
• Neurologic disorders: Patients with Parkinson's disease or other neurodegenerative disorders require specialized management 1

Monitoring and Follow-up

• Regular blood pressure measurements in both supine and standing positions
• Assess symptom improvement and quality of life
• Monitor for treatment complications, especially supine hypertension
• Adjust therapy based on response and side effects

Treatment Algorithm

1. Identify and address reversible causes
2. Implement non-pharmacologic measures for all patients
3. If inadequate response after 2-4 weeks, add pharmacologic therapy
4. Start with midodrine if no contraindications
5. Add or substitute fludrocortisone if needed
6. Adjust therapy based on symptom control and side effects

This approach focuses on improving orthostatic tolerance, reducing syncope risk, and enhancing quality of life while minimizing adverse effects from treatment.