Albumin: Clinical Overview and Applications
Albumin is a human-derived blood product manufactured from donated human plasma, used in specific clinical scenarios to improve hemodynamics, facilitate fluid removal, and manage complications of cirrhosis, though evidence supports its use in only limited clinical situations. 1
What is Albumin?
Albumin is the most abundant protein in human blood plasma, constituting more than 50% of serum proteins in healthy individuals. It has several important physiological functions:
- Maintenance of oncotic pressure in the vascular system
- Transport of various endogenous and exogenous substances
- Binding of toxins, medications, and bacterial products
- Antioxidant properties through free radical scavenging
- Modulation of inflammatory reactions 2, 3
Pharmaceutical Preparations
Albumin is commercially available in different formulations:
- Plasbumin-25 (25% albumin solution): Hyperoncotic solution that expands plasma volume by 3-4 times the volume administered by drawing fluid from interstitial spaces 4
- Plasbumin-5 (5% albumin solution): Iso-oncotic solution used for volume replacement
- Flexbumin: A brand name for human albumin solution
These preparations are stabilized with sodium caprylate and acetyltryptophan, contain no preservatives, and must be administered intravenously. Each vial undergoes heat treatment at 60°C for 10 hours to reduce the risk of viral transmission 4.
Evidence-Based Clinical Applications
According to the International Collaboration for Transfusion Medicine Guidelines (2024), albumin is recommended in only a few specific clinical scenarios 1:
Recommended Uses:
- Cirrhosis with large-volume paracentesis (>5L): 6-8g albumin per liter of ascitic fluid removed 5
- Spontaneous bacterial peritonitis: 1.5g/kg on day 1, followed by 1g/kg on day 3 5
- Hepatorenal syndrome: Used with vasoconstrictors 5
Not Recommended For:
- First-line volume replacement in critically ill adults
- Increasing serum albumin levels in hypoalbuminemia alone
- Routine use in most ICU patients
- Chronic nephrosis
- Protein nutrition in chronic cirrhosis, malabsorption, or undernutrition 1, 4
Clinical Considerations
Mechanism of Action
When administered intravenously to an adequately hydrated patient, 20mL of 25% albumin draws approximately 70mL of fluid from extravascular tissues into circulation within 15 minutes, increasing total blood volume and reducing hemoconcentration 4.
Potential Adverse Effects
- Fluid overload
- Hypotension
- Hemodilution requiring RBC transfusion
- Anaphylaxis
- Peripheral gangrene from dilution of natural anticoagulants 1
Cost Considerations
Albumin is expensive (approximately $130/25g in US dollars) and requires large volumes of plasma for manufacturing, making cost-effectiveness an important consideration when selecting appropriate clinical scenarios for its use 1.
Special Populations
Pediatric Patients
- Limited data exists on albumin use in children with cirrhosis and ascites
- Diuretic therapy typically starts with spironolactone (1-4 mg/kg/day) with or without furosemide (0.5 mg/kg twice daily) 1
Common Pitfalls
Overuse in situations without evidence support: Most clinical scenarios do not benefit from albumin administration despite common practice 1
Inadequate hydration: When using hyperoncotic albumin (25%), patients must be adequately hydrated or additional crystalloids must be given to prevent dehydration 4
Exceeding recommended doses: Total dose should not exceed the level of albumin found in normal individuals (about 2g per kg body weight) in the absence of active bleeding 4
Ignoring alternatives: In many cases, crystalloids are equally effective and significantly less expensive than albumin for volume replacement 1
The evidence clearly demonstrates that albumin has specific, limited indications where it provides clinical benefit, but it should not be used routinely for volume replacement or correction of hypoalbuminemia alone.