COLLOIDS

 

INTRODUCTION: Colloids are proteins, starches, or other large molecules that remain in the blood for a long time because they are too large to easily cross the capillary membranes.

EFFECTS OF COLLOIDS: While circulating, they have the same effect as hypertonic solutions, drawing water molecules from the cells and tissues into the plasma through their ability to increase plasma osmolality and osmotic pressure. Sometimes called plasma volume expanders, these solutions are particularly important in treating hypovolemic shock due to burns, hemorrhage, or surgery

EXAMPLES OF COLLOIDS: The most commonly used colloid is normal serum albumin, which is featured as a prototype drug for shock. Several colloid products contain dextran, a synthetic polysaccharide. Dextran infusions can double the plasma volume within a few minutes, although its effects last only about 12 hours.

Plasma protein fraction is a natural volume expander that contains 83% albumin and 17% plasma globulins. Plasma protein fraction and albumin are also indicated in patients with hypoproteinemia. Hetastarch is a synthetic colloid with properties similar to those of 5% albumin, but with an extended duration of action.

RELATED;

1.  INTRAVENOUS INFUSION OF FLUIDS

2.  PLASMA VOLUME EXPANDERS

3.  ANATOMY AND PHYSIOLOGY

REFERENCES