Şocul anafilactic

Abstract

Rezumat Şocul anafilactic (anafilaxie, anafilaxie acută) — constituie o reacţie alergrică sistemică de hipersensibilitate imediată, secundară unei stimulări antigenice specifice, mediate de IgE şi eliberării masive şi brutale de mediatori conţinuţi în principal în mastocite şi în bazofile din ţesuturi şi sângele periferic la un contact repetat al organismului cu antigenul (5). Şocul anafilactic este definit ca o insuficienţă circulatore acută de origine imunologică. Şocul anafilactic este expresia clinică a reacţiei alergice generalizate, ce rezultă din interacţiunea între un antigen şi un anticorp de tipul IgE şi uneori IgG4.

Summary Anaphylactic shock and anaphylactoid reactions are due to the sudden release of preformed inflammatory mediators from mast cells and basophils. After exposure to the offen dind stimulus, initial symptoms may appear within seconds to minutes or may be delayed as long as 1 hour. The most common agents causing anaphylactic shock and anaphylactoid reactions are haptens, serum products, foods, venoms, hormones enzymes, miscellaneous. The clinical manifestantions of anaphylaxis are rariable. Reactions may be transient, protracted or biphasic and vary in severity from mild to fatal. The commones feature is profund vasodilatation with hyhotension and tachycardia: These haemodynamic changes may occur in isolation, but are of the accompanied by dispnoea and cutaneous manifestation. Loss of protein‑rich fluid into the tissues through the „leaky“ microvasculature appears as oedema, often most obious in the face but, more dangerously, may cause laryngeal obstruction with stridor. Management of the patient in anaphylactic shock is directed toward maintaining a patent airway and counteracting the anaphylactic reactions. Interventions include the following: The drug of first choice for severe anaphylactic reactions is adrenaline. Aggressively support the patient΄s airay, breathing and circulation Provide high‑flow oxygen Airway obstruction can develop rapidly, so early intubation is indicated. Establish iv access and administer crystalloids and colloid to treat hypotension. Administer a nebulized bronchodilator (albuterol) for bronchospasm. Give diphenhydramine (Benadryl), a histamin 1 blocker and famotidine a histamin 2 blocker, to decrease circulating histamine levels. Steroids are used to limit the inflammatory response.