What are the differences in clinical use between Albumin (human albumin) 5% and 25%?

Albumin 5% vs 25%: Clinical Use Differences

Albumin 25% should be used for volume expansion with sodium restriction concerns, while albumin 5% is preferred when additional volume expansion without sodium restriction is needed.

Key Differences Between Albumin 5% and 25%

Concentration and Volume

• 25% Albumin:

  • Hyperoncotic solution (25g protein/100mL)
  • Smaller infusion volume for same amount of albumin
  • Minimal volume expansion beyond the albumin itself
  • Used when fluid restriction is necessary 1

• 5% Albumin:

  • Iso-oncotic solution (5g protein/100mL)
  • Larger infusion volume for same amount of albumin
  • Contains electrolyte solution
  • Lower viscosity making it easier to infuse 2

Sodium Content

• 25% Albumin: Lower sodium load (5-fold less sodium than 5% solution) 1
• 5% Albumin: Higher sodium load (5-fold more sodium than 25% solution) 1

Clinical Applications

Paracentesis

• For paracentesis >5L:
  • Both 20% and 25% albumin are strongly recommended at a dose of 8g albumin/L of ascites removed 1
  • 5% albumin can be used but delivers 5-fold higher sodium load 1

Spontaneous Bacterial Peritonitis (SBP)

• For SBP with increased or rising serum creatinine:
  • Recommended dose: 1.5g albumin/kg within 6 hours of diagnosis, followed by 1g/kg on day 3 1
  • 20-25% solutions preferred to minimize volume overload 1

Volume Expansion

• When volume expansion is primary goal:

  • 5% albumin provides equivalent plasma volume expansion as 25% (approximately 11mL/g of retained albumin) 2
  • 5% is easier to infuse due to lower viscosity 2

• When sodium restriction is needed:

  • 25% albumin preferred to minimize sodium load 1

Safety Considerations

Dilution Warning

• Never dilute 25% albumin with sterile water alone as this creates a hypotonic solution that can cause hemolysis (potentially fatal) 3
• If dilution is necessary, use 0.9% NaCl or 5% dextrose 3

Volume Overload Risk

• Higher risk with 5% albumin due to larger volume administration
• Patients with cardiac, renal, or pulmonary compromise may benefit from 25% formulation 1

Cost Considerations

• Albumin is expensive (can account for up to 30% of pharmacy budgets in some hospitals) 4
• Using the appropriate concentration for specific indications optimizes cost-effectiveness
• No proven benefit for routine correction of hypoalbuminemia 5, 6

Algorithm for Selecting Albumin Concentration

1. Assess primary clinical need:

   • Volume expansion with sodium tolerance → 5% albumin
   • Volume expansion with sodium restriction → 25% albumin
   • Paracentesis >5L → 20-25% albumin (8g/L removed)
   • SBP with renal dysfunction → 20-25% albumin

2. Consider patient factors:

   • Cardiac/renal/pulmonary compromise → Prefer 25% to minimize volume
   • Need for rapid infusion → 5% has lower viscosity
   • Electrolyte concerns → 25% has lower sodium content

3. Administration considerations:

   • Both provide equivalent oncotic effect per gram of albumin
   • 5% is easier to administer (lower viscosity)
   • 25% requires less total volume for same albumin dose

Remember that regardless of concentration, albumin should be used judiciously as evidence for many indications remains limited, with strongest support for use in large-volume paracentesis and SBP with renal dysfunction.