Colloids (plasma substitutes)

Key examples

• Gelatins
• Albumin

 

Common indications

• Colloids are used to expand circulating volume in states of circulatory compromise (including shock)
• In cirrhotic liver disease, albumin is used to prevent effective hypovolaemia in large-volume paracentesis (ascitic fluid drainage).

 

Mechanisms of action

• In relation to fluid therapy, a colloid is a solution containing a large, osmotically active molecule, such as albumin or modified gelatin. 
• The large molecules cannot readily diffuse out of vessels, and their osmotic effect ‘holds’ the infused fluid in the plasma.

 

Important adverse effects

• Excessive administration of colloid fluids may cause a fall in cardiac output and precipitate cardiac failure by increasing left ventricular filling beyond the point of maximal contractility on the Starling curve.

 

Warnings

• To be added