Among the many biological functions of the albumin molecule, the fundamental is its oncotic role due to its colloid-osmotic properties.
This module builds on The Albumin Molecule – Structures and Functions. It provides a deeper dive into the oncotic properties of albumin.
Key Takeaways
Albumin contributes to the plasma oncotic pressure both with a direct osmotic effect (due to its concentration) and through the Gibbs-Donnan effect (attracting positively charged molecule).
Albumin is also the predominant protein in the interstitium, thus contributing to the interstitial colloid osmotic pressure. The regulation of fluid distribution is due to the colloid-osmotic pressure gradient across the capillary membrane, rather than the absolute albumin serum concentration.
Albumin solutions have a greater oncotic power than crystalloids, and a favorable safety profile compared with synthetic colloids, although with a higher cost.
The role of albumin in counteracting effective hypovolemia, a key pathophysiological event in decompensated cirrhosis, represented the first rationale for its use in clinical practice.
