Mechanisms and management of allergic reactions in the surgical patient.

The use of anesthetic agents, drugs and chemicals during anesthesia induces a certain number of anaphylactoic or anaphylactoid reactions. The incidence of anaphylaxis during general anesthesia, according to a recent study, is 1:4500. Despite appropriate treatment, mortality is about 6%. Different mechanisms are involved in mortality. Multiple risk factors have been identified in at-risk patients. With adequate understanding of the pathophysiological events that occur during anaphylaxis, anesthetists may avoid the occurrence of allergic reaction or be better prepared to manage these serious situations that may become fatal. This article covers different areas associated with anaphylactic and anaphylactoid reactions. Focus is placed on the different mechanisms of allergic reaction, and special attention is given to the clinical aspects of this complication. Treatment of these reactions as well as steps in prevention perioperatively are highlighted.