Plasma protein solutions and synthetic plasma substitutes have an established role in therapy in many areas of clinical medicine. Although there have been many advances in the field of plasma volume expanders, an effective, stable, readily available and economical solution, free from side effects remains elusive. In particular, all plasma volume expanders may be associated with a small, but significant incidence of side effects. Allergic and anaphylactoid reactions are the most feared, but questions about prolonged storage and effects on haemostasis and renal function should be considered. Plasma protein fraction may be associated with hypotension, probably due to kinin activation. In the fully conscious patient, features of vasodilatation including flushing, fullness in the head, nasal stuffiness, may also be noted. There have also been reports of true anaphylactic type reactions occurring in atopic subjects after the infusion of small amounts of plasma protein solution. Modified fluid gelatins are well known to release histamine when infused rapidly. The reactions are usually confined to the skin and present clinically as pruritis, urticaria or flushing. There are also reports of anaphylactic reactions not related to dosage which are probably immune in origin. The dextrans are well recognised to cause such anaphylactoid reactions. Accepting that anaphylactoid and anaphylactic reactions may occur in association with plasma volume expanders, anticipation, diagnosis and rapid institution of therapy determine the outcome of these reactions.
