Adverse drug reactions.

INTRODUCTION Surgical patients are exposed to multiple foreign substances in the perioperative period including drugs, blood products, or environmental antigens such as latex. Because any substance can produce an allergic or adverse reaction, clinicians must be ready to manage patients in this perioperative environment. The most life-threatening form of an allergic reaction is anaphylaxis, however, the clinical presentation of anaphylaxis may represent different immune and nonimmune responses.1 There is confusion in the literature about the term anaphylaxis, and multiple terms have been reported to describe this reaction. In recent years, anaphylaxis has been redefined as a severe, lifethreatening, generalized or systemic hypersensitivity reaction, mainly mediated by immunoglobulin E (IgE) antibodies.2 Further, anaphylaxis represents a serious allergic reaction that is rapid in onset and may cause death.3-6 The term anaphylactoid, often used to describe for non IgE-mediated reactions, is confusing and probably should no longer be used. For the practicing clinician, anaphylaxis is best defined as a clinical syndrome characterized by acute cardiopulmonary collapse following antigen (also called allergen) exposure. Much of the confusion about anaphylaxis in the literature is because many older anesthetic agents (e.g., d-tubocurarine) could directly degranulate mast cells. The incidence of immune-mediated anaphylaxis during anesthesia ranges from 1 in 10,000 to 1 in 20,000 based on recent reports.7 This presentation will define the spectrum of life threatening anaphylactic and allergic reactions an anesthesiologist may encounter.