Albumin
Background
- Most abundant serum protein; synthesized by the liver
- Major determinant of oncotic pressure and carrier for calcium, bilirubin, drugs
Normal Values
- Normal: 3.5-5.0 g/dL
Interpretation
- Low albumin: liver disease, nephrotic syndrome, malnutrition, critical illness, protein-losing enteropathy
- Marker of chronic nutritional status and illness severity; not useful as an acute-phase reactant
- Low albumin affects interpretation of total calcium and anion gap
- Corrected calcium = total Ca + 0.8 x (4.0 - albumin)
- Corrected anion gap: increase AG by 2.5 for every 1 g/dL decrease in albumin below 4.0
- Serum albumin <2.0 g/dL is associated with increased morbidity and mortality in critically ill patients