8 Colloid safety: fact and fiction

Colloids are indispensible for volume support, but all of them, even human serum albumin, have side-effects. These include unspecific effects such as fluid overload, impairment of renal function and dilution of plasma coagulation factors, as well as specific effects on certain plasma components and cellular elements. Some of these secondary effects are regularly used therapeutically, for example thromboprophylaxis from dextran. Allergic reactions are seen with all colloids but most frequently with gelatin, which also has the poorest volume effect. Allergic reactions to dextran have been successfully prevented by hapten inhibition. Severe and persistent itching has been described after hydroxyethyl starch and is associated with tissue storage of undegradable hydroxyethyl starch residues. With human serum albumin, the main problems are limited availability and price. When choosing a colloid, it is important to weigh the therapeutic value against the risk for all types of adverse effects and not only allergic reactions.