When do you use 5% (five percent) albumin versus 25% (twenty-five percent) albumin?

When to Use 5% vs. 25% Albumin

Use 5% albumin for volume resuscitation when the patient is dehydrated or hypovolemic; use 25% albumin when the patient has adequate or excess total body water but needs oncotic support, such as in fluid overload states, large-volume paracentesis, or when concentrated protein replacement is needed. 1

Key Principle: Concentration Determines Fluid Movement

The fundamental difference between these formulations is their effect on fluid distribution:

• 5% albumin is iso-oncotic to plasma and primarily stays in the intravascular space, expanding plasma volume by approximately the volume infused 1
• 25% albumin is hyperoncotic and draws 3-4 times its volume from the interstitial space into the intravascular compartment, provided the patient has adequate interstitial fluid 1

Clinical Scenarios for 5% Albumin

Volume Resuscitation in Dehydrated/Hypovolemic Patients:

• Use 5% albumin when the patient needs both volume expansion AND is actually depleted of total body water 1
• Preferred for standard volume deficits in hypovolemic shock when crystalloids alone are insufficient 1
• In sepsis-induced hypotension with cirrhosis, 5% albumin showed higher 1-week survival (43.5% vs. 38.3%, p=0.03) compared to normal saline 2

Cardiopulmonary Bypass Priming:

• Standard practice uses albumin with crystalloid to achieve hematocrit of 20% and plasma albumin of 2.5 g/100mL 1
• Either concentration can be used, adjusted for the priming volume needed 1

Clinical Scenarios for 25% Albumin

Large-Volume Paracentesis (>5L):

• Administer 8g albumin per liter of ascites removed using 20% or 25% albumin 3, 4
• Give after paracentesis completion to prevent post-paracentesis circulatory dysfunction 3
• The concentrated form minimizes additional volume administration in already fluid-overloaded patients 5

Spontaneous Bacterial Peritonitis:

• Dose: 1.5g/kg within 6 hours of diagnosis, then 1g/kg on day 3 2, 3
• Either 20% or 25% albumin can be used based on availability 3
• Reduces renal dysfunction by 72% and mortality by 47% 3

Fluid Overload with Hypoproteinemia:

• Use 25% albumin when the patient has total body fluid excess but low oncotic pressure 1
• Particularly valuable in ARDS with hypoproteinemia and volume overload, combined with diuretics 1
• In acute nephrosis not responding to steroids, 100mL of 25% albumin daily for 7-10 days with loop diuretics may control edema 1

Burns Beyond 24 Hours:

• After initial crystalloid resuscitation in the first 24 hours, 25% albumin maintains plasma colloid osmotic pressure 1
• Avoids additional volume loading in patients who have already received large crystalloid volumes 1

Intradialytic Hypotension:

• 25% albumin improved hypotension, lowest systolic BP, and ultrafiltration rate compared to saline in patients with serum albumin <30 g/L 2
• However, cost considerations ($20,000/year for thrice-weekly use) limit routine use 2

Critical Safety Considerations

Risk of Pulmonary Complications with 25% Albumin:

• In cirrhosis with sepsis-induced hypotension, 20% albumin caused more pulmonary complications than plasmalyte, requiring treatment discontinuation in 22% of patients 6
• The ALBIOS trial showed targeting specific albumin levels with daily infusions increased pulmonary edema and fluid overload 2
• Monitor closely for signs of volume overload when using concentrated albumin 2, 6

Avoid 25% Albumin in Dehydrated Patients:

• If the patient lacks adequate interstitial fluid, 25% albumin cannot exert its oncotic effect and may worsen intravascular depletion 1
• Must give additional crystalloids with 25% albumin in dehydrated patients, or use 5% albumin instead 1

Practical Algorithm

Step 1: Assess Total Body Water Status

• Dehydrated/hypovolemic → 5% albumin
• Euvolemic or hypervolemic → 25% albumin (if albumin indicated)

Step 2: Identify Specific Indication

• Cirrhosis with large-volume paracentesis → 25% albumin 3, 4
• Cirrhosis with SBP → 20-25% albumin 3
• Sepsis requiring large crystalloid volumes → 5% albumin as rescue therapy 2, 7
• Fluid overload + hypoproteinemia + diuretic resistance → 25% albumin with diuretics 1

Step 3: Monitor for Complications

• Watch for pulmonary edema, especially with 25% albumin 2, 6
• Ensure hemodynamic monitoring during resuscitation 2
• Avoid exceeding 2g/kg total albumin dose in absence of active bleeding 1

Common Pitfalls

• Do not use albumin concentration to treat hypoalbuminemia alone - serum albumin does not reflect albumin function in liver disease 3, 4
• Do not use 25% albumin for routine volume resuscitation - it requires adequate interstitial fluid to work and risks pulmonary complications 1, 6
• Do not assume 25% albumin is "stronger" for all indications - the plasma volume expansion per gram of albumin is similar (11 mL/g) regardless of concentration 8