What is the role of albumin (human albumin) in treating hypotension?

Role of Albumin in Treating Hypotension

Albumin should not be used as a first-line treatment for hypotension in most clinical scenarios, with specific exceptions for intradialytic hypotension in patients with hypoalbuminemia and certain cirrhotic conditions.

General Considerations for Albumin Use in Hypotension

Albumin is available in different concentrations (4-5% iso-oncotic and 20-25% hyperoncotic solutions) with varying effects on plasma volume expansion. According to the most recent guidelines, the role of albumin in treating hypotension is limited and context-specific 1.

When Albumin Is NOT Recommended:

• Critical illness: In critically ill adult patients (excluding those with thermal injuries and ARDS), intravenous albumin is not recommended for first-line volume replacement 1
• Cardiovascular surgery: No evidence supports albumin use over crystalloids for hypotension management during or after cardiac surgery, and it may actually increase risks of bleeding and infection 1
• General volume resuscitation: Crystalloids should be used as first-line therapy for most hypotensive states requiring fluid resuscitation 1

When Albumin MAY Be Considered:

1. Intradialytic hypotension in patients with hypoalbuminemia:

   • 25% albumin may improve hypotension, lowest intradialytic systolic BP, and ultrafiltration rate compared to saline in patients with serum albumin <30 g/L 1, 2
   • The 2021 randomized crossover trial showed improved outcomes with 25% albumin in this specific population 1

2. Cirrhosis-related conditions:

   • For hepatorenal syndrome (HRS) with hypotension: Albumin in combination with vasoconstrictors (terlipressin or noradrenaline) is more effective than albumin monotherapy 1
   • For post-paracentesis circulatory dysfunction (PICD): Albumin prevents hypotension following large-volume paracentesis 1

Dosing and Administration

When albumin is indicated for hypotension management:

• Administration route: Always administer intravenously 3
• Rate of administration: Should not exceed 2 mL per minute for 25% solution to prevent circulatory embarrassment and pulmonary edema 3
• Preparation: Can be administered undiluted or diluted in 0.9% Sodium Chloride or 5% Dextrose in Water 3
• Monitoring: Patients should always be monitored carefully to guard against circulatory overload 3

Special Considerations

Hypoalbuminemia as an Effect Modifier

The effectiveness of albumin for volume expansion appears to be greater when serum albumin levels are low (<25 g/L) 4. This suggests that hypoalbuminemia acts as an effect moderator in volume resuscitation, potentially making albumin more effective in these specific patients.

Potential Adverse Effects

• Paradoxical hypotension: Rapid infusion of 4% albumin can cause paradoxical hypotension, especially in patients taking ACE inhibitors (11% incidence in one study) 5
• Other adverse effects: Fluid overload, hemodilution requiring RBC transfusion, anaphylaxis, and peripheral gangrene from dilution of natural anticoagulants 1, 3

Cost Considerations

The high cost of albumin (approximately $20,000 per patient annually for thrice-weekly hemodialysis) makes it impractical as a routine treatment for hypotension when less expensive alternatives exist 1.

Alternative Approaches for Intradialytic Hypotension

Instead of albumin, consider:

• Midodrine (oral vasopressor)
• Higher dialysate calcium
• Lower dialysate temperature
• Individualized ultrafiltration rates 1

Conclusion for Clinical Practice

For most hypotensive states, crystalloids remain the first-line therapy. Reserve albumin for specific conditions like intradialytic hypotension with hypoalbuminemia or cirrhosis-related conditions where evidence supports its use. When using albumin, be vigilant about the risk of paradoxical hypotension, especially with rapid infusion in patients on ACE inhibitors.