Adrenaline for anaphylaxis -what is the evidence?

摘要

International and local anaphylaxis . guidelines prominently include the use of intramuscular adrenaline. However the evidence for its use is poor and the use of adrenaline in anaphylaxis is based largely on extrapolation from first principles, expert opinion and tradition. Data from basic sciences show the mechanisms of anaphylaxis are potentially amenable to therapy by adrenaline. The early use of adrenaline improves survival in animal models of anaphylaxis but delayed administration is ineffective. Studies of fatal and near-fatal anaphylaxis in humans delineate risk factors for anaphylaxis such as pre-existing asthma, a current asthma attack, food allergies (particularly peanuts, tree nuts and shellfish), reaction to trace amounts of foods and use of non-selective p-blockers. Most reactions occur in individuals with known food allergy and with accidental ingestion. Most studies of fatal anaphylaxis show that a lack or delay in administration of adrenaline is a frequent factor in death whereas early administration of adrenaline even in severe attacks is associated with survival. However, self-injectable adrenaline is underused even when it is available. Incorrect administration may also be an important factor,particularly with adrenaline given by needle and syringe rather than by autoinjector. Autoinjectors should be more widely available and teachers should be trained in the management of anaphylaxis and schools mandated to keep all appropriate emergency medication for named children at risk for anaphylaxis.