Core pharmacology

Introduction

Natural Colloid

Adverse Effects Toxicity

1. Risk of Creutzfeldt Jakob Disease and Parvovirus B19 (Resistant to heat treatment)
2. Pulmonary oedema
3. Has been associated with myocardial depression
4. Contraindicated in TBI

Distribution

Under normal circumstances 40% of albumin is intravascular and 60% is extravascular

Metabolism

Breakdown is predominantly by intracellular lysosome proteases under feedback control

Excretion

Albumin normally has a T1/2 of 19 days

Indications Uses

Plasma-volume replacement, priming of extracorporeal circuits, treatment of hypoalbuminaemic states and replacement fluid during therapeutic plasma exchange.

Presentation

Clear, straw-coloured human albumin solution available in approximately 4.5-5% and 20-25% preparations. The referenced text describes pasteurisation at 60 C for 10 hours, no preservatives and sodium content around 130-160 mmol/L.

Mechanism of action

Albumin contributes substantially to plasma colloid oncotic pressure and thereby regulates plasma volume. Concentrated albumin solutions draw fluid from the interstitial space into the circulation.

Physiological effects

Expands plasma volume. The haemodynamic effect depends on baseline circulating volume and capillary permeability. Concentrated 20-25% albumin may recruit several times the administered volume into the circulation over a short period.

Special Points

Clinical volume expansion is variable, especially in states with increased capillary permeability. Monitor for circulatory overload when administering albumin solutions.

Class Group

Human albumin, a fractionated plasma product used clinically as a colloid.