Indications for Albumin 5% in Blood Volume Expansion
Albumin 5% should be used for blood volume expansion in specific clinical scenarios including large-volume paracentesis (>5L), spontaneous bacterial peritonitis, severe burns (>20-30% TBSA), severe malaria with shock, and hypovolemic shock when crystalloids are insufficient. 1, 2, 3
Primary Indications for Albumin 5% Use
Cirrhosis-Related Indications
- Large-volume paracentesis (>5L): Administer albumin at 8g per liter of ascitic fluid removed to prevent post-paracentesis circulatory dysfunction 1, 2
- Spontaneous bacterial peritonitis: Give 1.5g/kg within 6 hours of diagnosis and 1g/kg on day 3 to prevent renal dysfunction and decrease mortality (reduces mortality by 47%) 1, 2
- Acute-on-chronic liver failure: Consider albumin even when removing <5L of ascitic fluid 2
Critical Care Indications
- Hypovolemic shock: Use as second-line therapy when patients require large volumes of crystalloids or have inadequate response to crystalloids 1, 3
- Severe burns: Consider in patients with burns covering 20-30% TBSA to reduce administered crystalloid volumes and decrease organ failure incidence 1
- Severe malaria with shock and coma: Human albumin solution is recommended as the resuscitation fluid of choice in children with severe malaria presenting with coma and features of shock 1
Mechanism and Efficacy
Albumin 5% expands plasma volume by approximately 0.74 times the infused volume, which is about 4 times more effective than Ringer's lactate (which expands plasma volume by only 0.18 times the infused volume) 4. The expansion effect is sustained with a half-life of approximately 5.5 hours 4.
When 50g of albumin is infused as a 5% solution, it typically increases plasma volume by about 500ml (or 11ml/g of retained albumin) 5. This expansion is less dependent on the concentration of the solution and more on the amount of albumin administered and the existing plasma volume deficit 5.
Practical Administration Guidelines
Dosing Considerations
- Hypovolemic shock: The total dose should not exceed 2g/kg body weight in the absence of active bleeding 3
- Burns: Typically administered at 1-2g/kg/day to maintain albumin levels >30g/L 1
- Paracentesis: 8g per liter of ascitic fluid removed (when >5L) 1, 2
Advantages of 5% vs. Higher Concentrations
- 5% albumin contains electrolytes and has lower viscosity, making it easier to infuse 5
- While 20% albumin has greater volume expansion per ml (2.09 times infused volume vs. 0.74 for 5%), the 5% solution is often preferred for ease of administration 5, 4
Cautions and Contraindications
- Allergic reactions: Though rare compared to other colloids, anaphylactoid reactions can occur 6
- Cardiovascular surgery: Evidence suggests potential increased morbidity (bleeding, resternotomy, infection) when albumin is used in low-risk cardiac surgery compared to Ringer's lactate 1
- Pediatric critical care: In children with severe febrile illness and hypoperfusion, albumin boluses have been associated with excess mortality compared to no bolus strategy 1
Evidence-Based Algorithm for Albumin 5% Use
First, assess if patient falls into an evidence-based indication category:
- Cirrhosis with large-volume paracentesis (>5L)
- Spontaneous bacterial peritonitis
- Severe burns (>20-30% TBSA)
- Hypovolemic shock unresponsive to crystalloids
- Severe malaria with shock (especially in children)
If yes, determine appropriate dosing based on indication:
- Paracentesis: 8g/L of fluid removed
- SBP: 1.5g/kg initially, then 1g/kg on day 3
- Burns: 1-2g/kg/day
- Shock: Titrate to hemodynamic response, not exceeding 2g/kg
Monitor for response and complications:
- Hemodynamic parameters (blood pressure, heart rate)
- Urine output (target >1ml/kg/hour)
- Signs of fluid overload
- Allergic reactions
Remember that while albumin is effective for volume expansion, it is considerably more expensive than crystalloids and should be used judiciously according to evidence-based guidelines.