In a hypoalbuminemic patient (e.g., cirrhosis with ascites or septic shock), does 25% albumin increase intravascular volume and improve urine output?

Does 25% Albumin Increase Intravascular Volume and Improve Diuresis?

Yes, 25% albumin does increase intravascular volume through oncotic expansion—producing plasma volume expansion equal to approximately twice the infused volume—but it does NOT reliably improve diuresis and should NOT be used to treat hypoalbuminemia alone or to enhance diuretic response. 1

Mechanism of Volume Expansion

25% albumin is hyperoncotic and expands plasma volume by drawing fluid from the interstitial space into the intravascular compartment. 1 Specifically:

• 100 mL of 25% albumin (25 g) increases serum albumin by approximately 0.2–0.3 g/dL 2
• The volume expansion effect is roughly double the infused volume due to oncotic pressure 1
• This effect is transient, lasting hours to days, not weeks 1

However, approximately 58% of infused albumin undergoes rapid degradation, and a 15% rise in serum albumin triggers a 39% increase in degradation rate—meaning higher or repeated doses do not proportionally sustain serum levels. 3, 1

Evidence-Based Indications in Hypoalbuminemic Patients

Large-Volume Paracentesis (>5 L) in Cirrhosis

• Administer 8 g albumin per liter of ascites removed using 20% or 25% solution after paracentesis completion to prevent post-paracentesis circulatory dysfunction 3, 1, 4
• For a 10-liter paracentesis, this equals 80 g total (320 mL of 25% albumin) 1
• The 25% formulation minimizes infusion volume compared to 5% solution, which is critical when sodium restriction is required (5% albumin delivers five-fold more sodium) 1

Spontaneous Bacterial Peritonitis (SBP) in Cirrhosis

• Give 1.5 g/kg within 6 hours of SBP diagnosis, followed by 1.0 g/kg on day 3 1, 4
• This regimen reduces renal dysfunction by 72% (OR 0.21) and mortality by 66% (OR 0.34) 1
• For a 70 kg patient, this totals 105 g initially + 70 g on day 3 = 175 g over 3 days 1

Hepatorenal Syndrome

• Albumin is used in combination with vasoconstrictors (e.g., terlipressin) at 10–20 g/day for up to 20 days 1, 4

Septic Shock in Cirrhosis

• 5% albumin showed higher 1-week survival (43.5% vs. 38.3%, p=0.03) compared to normal saline in cirrhotic patients with sepsis-induced hypotension 1
• Caution: 25% albumin may increase risk of pulmonary complications in this setting 1

Why Albumin Does NOT Improve Diuresis

Major guidelines explicitly recommend AGAINST using albumin to correct hypoalbuminemia alone or to enhance diuretic response. 1, 4

• The 2024 International Collaboration for Transfusion Medicine Guidelines state albumin should not be used for treatment of hypoalbuminemia in cirrhosis, nephrotic syndrome, or malnutrition without specific acute complications 1, 4
• Albumin does not mobilize extravascular fluid when combined with diuretics 4
• For uncomplicated ascites, first-line treatment remains sodium restriction (88 mmol/day) plus oral spironolactone ± furosemide—not albumin 3

Critical Safety Concerns

Fluid overload and pulmonary edema are documented complications, particularly with doses exceeding 87.5 g or in patients with existing volume overload. 1, 4

• Adding albumin to a patient with fluid overload will worsen—not improve—the condition 4
• Rapid infusion of high doses (e.g., 2.05 g/kg over 2 hours in stroke trials) caused pulmonary edema in 13% of patients 1
• Other documented complications include hypotension, hemodilution requiring transfusion, anaphylaxis, and peripheral gangrene from dilution of natural anticoagulants 1, 4

Common Pitfalls to Avoid

1. Do not use albumin to "boost" diuretic response in hypoalbuminemic patients—this is not evidence-based and wastes resources (albumin costs ~$130 per 25 g) 1, 4

2. Do not give daily albumin for chronic hypoalbuminemia—the effect is transient, and repeated dosing increases degradation without sustained benefit 1, 2

3. Do not use albumin for routine volume resuscitation in critically ill patients without cirrhosis—crystalloids are equally effective and far less expensive 1, 4

4. Avoid albumin in cardiovascular surgery—the largest trial (1,386 patients) showed increased postoperative bleeding, need for resternotomy, and infection compared to Ringer's lactate 1

Optimizing Diuresis Without Albumin

For patients with fluid overload and hypoalbuminemia, optimize diuretic therapy instead: 4

• Continue furosemide at 0.5–2 mg/kg per dose, up to 6 times daily (maximum 10 mg/kg/day) 4
• Add a thiazide diuretic or amiloride for synergistic effect 4
• Monitor electrolytes, blood pressure, kidney function, and fluid status closely 4

Bottom line: 25% albumin expands intravascular volume through oncotic mechanisms but does not improve diuresis. Its use should be restricted to specific, time-limited indications in cirrhosis complications—not for treating low albumin levels or enhancing diuretic response. 1, 4, 5