How to treat hypotension?

Management of Hypotension

The treatment of hypotension should focus on identifying and addressing the underlying cause while implementing both non-pharmacological and pharmacological interventions tailored to the specific type of hypotension. 1

Types of Hypotension and Initial Assessment

Orthostatic Hypotension

• Defined as a decrease in systolic BP ≥20 mmHg or diastolic BP ≥10 mmHg within 3 minutes of standing 1, 2
• Common symptoms: dizziness, lightheadedness, blurred vision, weakness, fatigue, nausea, palpitations, headache 2
• Less common symptoms: syncope, dyspnea, chest pain, neck and shoulder pain 2

Acute Hypotension

• Often due to volume depletion, medication effects, or acute illness
• Requires prompt intervention to prevent end-organ damage

Non-Pharmacological Management

For Orthostatic Hypotension:

1. Fluid intake:

   • Acute water ingestion (240-480 mL) for temporary relief 1
   • Increase daily fluid intake to 2-2.5L 1

2. Salt intake:

   • Moderate salt intake if not contraindicated by other conditions 1
   • Note: Paradoxically, adding salt to water may attenuate the acute pressor response compared to water alone 3

3. Physical counter-maneuvers:

   • Isometric exercises: leg crossing, lower body muscle tensing, handgrip 1
   • Squatting (most effective counter-pressure maneuver) 1
   • Gradual staged movements with postural change 1

4. Compression garments:

   • Thigh-high or abdominal compression to improve orthostatic tolerance 1

5. Sleep position:

   • Elevate head of bed 10-20° during sleep 1

For Acute Hypotension:

1. Fluid resuscitation:
   • Initial normal saline fluid bolus (10-20 mL/kg; maximum 1,000 ml) for hypotension due to CRS 4
   • For calcium channel blocker toxicity: small boluses (5-10 mL/kg) of normal saline 4

Pharmacological Management

For Orthostatic Hypotension:

1. First-line medications:

   • Midodrine: Alpha-1 agonist, 10 mg up to 2-4 times daily (last dose not later than 6 PM to prevent supine hypertension) 1, 5
   • Fludrocortisone: Mineralocorticoid, 0.05-0.1 mg daily, titrated to 0.1-0.3 mg daily 1

2. Second-line medications:

   • Droxidopa: Particularly useful in patients with Parkinson's disease, pure autonomic failure, and multiple system atrophy 1
   • Erythropoietin: Consider in patients with anemia and severe autonomic dysfunction (25-75 U/kg three times weekly) 1

For Acute Hypotension:

1. Vasopressors:

   • Epinephrine and norepinephrine are more effective than dopamine for raising blood pressure in tricyclic antidepressant toxicity 4
   • For calcium channel blocker toxicity: consider norepinephrine or epinephrine 4
   • For beta-blocker toxicity: high-dose epinephrine infusion may be effective 4

2. Other agents:

   • Glucagon: Consider for beta-blocker toxicity (5-10 mg over several minutes followed by IV infusion of 1-5 mg/hour in adolescents) 4
   • Calcium: For calcium channel blocker toxicity, infuse 20 mg/kg of 10% calcium chloride over 5-10 minutes; if beneficial, give infusion of 20-50 mg/kg per hour 4

Special Considerations

Hemodialysis-Related Hypotension:

1. Review and adjust dry weight if hypotension occurs with signs of improving nutrition 4
2. Modify ultrafiltration:
   • Decrease hourly ultrafiltration rate by extending treatment duration 4
   • Consider sequential ultrafiltration/clearance 4
3. Dialysate modifications:
   • Increase dialysate sodium concentration (148 mEq/L) early in session, followed by decrease ("sodium ramping") 4
   • Use bicarbonate-containing dialysate instead of acetate-containing dialysate 4
   • Reduce dialysate temperature from 37°C to 34-35°C 4
4. Pharmacological intervention:
   • Midodrine administered within 30 minutes of hemodialysis initiation can minimize intradialytic hypotensive events 4

Medication-Induced Hypotension:

• Identify and discontinue medications that may cause or worsen hypotension, such as:
  • Antihypertensives
  • Diuretics
  • Alpha-blockers
  • Vasodilators
  • Tricyclic antidepressants 1

Monitoring and Follow-up

1. Regular blood pressure measurements in supine and standing positions 1
2. Monitor for supine hypertension, especially with pressor medications 1, 5
3. Evaluate treatment effectiveness based on symptom improvement rather than blood pressure normalization 1

Treatment Goals

The primary goal is to minimize symptoms and improve standing time for activities of daily living, not to normalize blood pressure 1, 6. Treatment should aim to improve hypotension without causing excessive supine hypertension 6.

Cautions

1. Midodrine can cause marked elevation of supine blood pressure (>200 mmHg systolic) 5
2. Patients should avoid taking midodrine if they will be supine for any length of time - last daily dose should be 3-4 hours before bedtime 5
3. Monitor for drug interactions - midodrine may interact with cardiac glycosides, other vasoconstrictors, MAO inhibitors, and alpha-adrenergic blocking agents 5

Remember that chronic hypotension is associated with considerable morbidity and requires proper evaluation and management to improve quality of life 7.