ALBUMIN
1. BASIC OVERVIEW
Albumin is the most abundant plasma protein synthesized by the liver (~10–15 g/day).
- Normal serum level: 3.5–5.0 g/dL
- Half-life: ~18–20 days
Key Physiological Roles
- Oncotic pressure maintenance (~70–80%)
- Transport protein
- Hormones (thyroxine, cortisol)
- Drugs (e.g., Warfarin, Phenytoin)
- Buffering (acid-base)
- Antioxidant / anti-inflammatory effects
- Endothelial stabilization (glycocalyx protection)
2. PREPARATIONS & TYPES
Available Forms
|
Type |
Concentration |
Characteristics |
|
Iso-oncotic albumin |
4–5% |
Volume expander (like plasma) |
|
Hyperoncotic albumin |
20–25% |
Pulls fluid from interstitium |
Key Differences
|
Feature |
5% Albumin |
20% Albumin |
|
Oncotic pressure |
≈ Plasma |
↑↑ High |
|
Fluid shift |
Minimal |
Strong intravascular recruitment |
|
Use |
Shock resuscitation |
Edema/ascites |
3. PHARMACOKINETICS IN CRITICAL ILLNESS
In ICU Patients:
- ↑ Capillary leak → albumin escapes into interstitium
- ↓ Synthesis (sepsis, liver failure)
- ↑ Catabolism
Result:
- Shortened effective half-life
- Reduced oncotic efficacy
4. INDICATIONS IN CCM
A. SEPTIC SHOCK
Evidence:
- SAFE Trial
- ALBIOS Trial
- Surviving Sepsis Campaign
Recommendations:
- Use crystalloids first
- Add albumin if:
- Large volumes required
- Persistent hypoalbuminemia
SSC (2021):
“Suggest albumin in addition to crystalloids in patients requiring substantial fluid resuscitation”
B. ARDS
- Albumin + diuretics → improves oxygenation (temporary)
- Mechanism:
- ↓ Extravascular lung water
- ↑ oncotic pressure
Not routine; selected cases only
C. TRAUMATIC BRAIN INJURY (TBI)
Contraindicated
- SAFE subgroup → ↑ mortality in TBI with albumin
- Mechanism:
- ↑ cerebral edema (hypo-osmolar effect)
D. HYPOVOLEMIC SHOCK
- Alternative to crystalloids
- No mortality benefit over saline
Consider when:
- Fluid overload risk
- Hypoalbuminemia
E. LIVER CIRRHOSIS
1. Large Volume Paracentesis
- Give albumin if >5 L removed
- Dose: 6–8 g per L ascitic fluid removed
2. Spontaneous Bacterial Peritonitis (SBP)
- Prevents renal failure
- Dose:
- Day 1: 1.5 g/kg
- Day 3: 1 g/kg
3. Hepatorenal Syndrome (HRS)
- Albumin + vasoconstrictor (e.g., Terlipressin)
Strong guideline-backed indication
F. HYPOALBUMINEMIA
Not an indication alone
- No benefit in:
- Nutrition
- Chronic illness
- ICU hypoalbuminemia correction alone
G. DRUG BINDING & TOXICITY
- Low albumin → ↑ free drug fraction
- Important in ICU drugs:
- Phenytoin
- Warfarin
6. DOSING STRATEGIES
General ICU Use
- 5%: 250–500 mL bolus
- 20%: 100 mL over 30–60 min
Target-based therapy:
- Serum albumin goal (ALBIOS): ~3 g/dL (not routine practice)
7. ADVERSE EFFECTS
Common:
- Fluid overload (especially 5%)
- Hypotension (rapid infusion)
Serious:
- Anaphylaxis (rare)
- Pulmonary edema
- Hemodilution
8. CONTROVERSIES
Does albumin improve survival?
NO (overall ICU population)
When is albumin clearly beneficial?
✔ Cirrhosis (SBP, HRS, paracentesis)
Harmful situations?
TBI
