Anaphylactic reactions associated with anaesthesia

Anaphylaxis is a severe life-threatening generalized or systemic hypersensitivity reaction, which can be divided into allergic and non- allergic anaphylaxis. The incidence of anaphylaxis during general anaesthesia is between 1 in 10,000 and 1 in 20,000. Muscle relaxants, antibiotics and intravenous colloids are the most frequent trigger agents. Clinical features of an anaphylactic reaction usually occur within minutes and most commonly include hypotension, bronchospasm or rash. A suspected anaphylactic reaction is an anaesthetic emergency requiring an ABC approach with specific attention to removal of potential causative agents and titration of adrenaline to symptoms. Secondary management includes chlorphenamine, hydrocortisone, salbutamol, and vasopressors. Anaphylaxis is associated with mast cell degranulation - the subsequent circulating levels of mast cell tryptase can be used to aid diagnosis. All patients with a suspected anaphylaxis reaction should be referred to a specialist allergy or immunology centre for further investigation. The diagnosis is dependent on history, skin tests and blood tests. Following an anaphylactic reaction a letter confirming the diagnosis and outlining a plan for future anaesthesia should be sent to the patient and their general practitioner. The reaction should also be reported to the Medicines and Healthcare Products Regulatory Agency and to the Association of Anaesthetists of Great Britain and Ireland National Anaesthetic Anaphylaxis Database.