BNF for Children 2011-2012

BNFC 2011–2012 3.4.3 Allergic emergencies 159Indication and doseProphylaxis of severe persistent allergicasthma (see notes above). By subcutaneous injectionChild 6–18 years according to immunoglobulin Econcentration and body-weight, consult productliteratureXolair c (Novartis) TAInjection, powder for reconstitution, omalizumab, netprice 150-mg vial = £256.15 (with solvent)Excipients include sucrose 108 mg/vial. administering high-flow oxygen (section 3.6) andintravenous fluids (section 9.2.2);. administering an antihistamine, such as chlorphenamine,(section 3.4.1) by slow intravenous injectionor intramuscular injection as adjunctive treatmentgiven after adrenaline. An intravenouscorticosteroid (section 6.3.2) such as hydrocortisone(preferably as sodium succinate) is of secondaryvalue in the initial management of anaphylaxisbecause the onset of action is delayed for severalhours, but should be given to prevent further deteriorationin severely affected children.3.4.3 Allergic emergenciesAdrenaline (epinephrine) provides physiological reversalof the immediate symptoms associated with hypersensitivityreactions such as anaphylaxis and angioedema.AnaphylaxisAnaphylaxis is a severe, life-threatening, generalised orsystemic hypersensitivity reaction. It is characterised bythe rapid onset of respiratory and/or circulatory problemsand is usually associated with skin and mucosalchanges; prompt treatment is required. Children withpre-existing asthma, especially poorly controlledasthma, are at particular risk of life-threatening reactions.Insect stings are a recognised risk (in particularwasp and bee stings). Latex and certain foods, includingeggs, fish, cows’ milk protein, peanuts, sesame, shellfish,soy, and tree nuts may also precipitate anaphylaxis.Medicinal products particularly associated with anaphylaxisinclude blood products, vaccines, allergen immunotherapypreparations, antibacterials, aspirin and otherNSAIDs, and neuromuscular blocking drugs. In the caseof drugs, anaphylaxis is more likely after parenteraladministration; resuscitation facilities must always beavailable when giving injections associated with specialrisk. Refined arachis (peanut) oil, which may be presentin some medicinal products, is unlikely to cause anallergic reaction—nevertheless it is wise to check thefull formula of preparations which may contain allergens.Treatment of anaphylaxisFirst-line treatment includes:. securing the airway, restoration of blood pressure(laying the child flat and raising the legs, or in therecovery position if unconscious or nauseous and atrisk of vomiting);. administering adrenaline (epinephrine) by intramuscularinjection (for doses see IntramuscularAdrenaline, below); the dose should be repeated ifnecessary at 5-minute intervals according to bloodpressure, pulse, and respiratory function [important:possible need for intravenous route usingdilute solution (Adrenaline 1 in 10 000), see IntravenousAdrenaline p. 160];Continuing respiratory deterioration requires furthertreatment with bronchodilators including inhaled orintravenous salbutamol (see p. 139), inhaled ipratropium(see p. 141), intravenous aminophylline (seep. 143), or intravenous magnesium sulphate [unlicensedindication] (see Management of Acute Asthma, p. 134).In addition to oxygen, assisted respiration and possiblyemergency tracheotomy may be necessary.When a child is so ill that there is doubt as to theadequacy of the circulation, the initial injection of adrenalinemay need to be given as a dilute solution by theintravenous route, or by the intraosseous route if venousaccess is difficult—for details of cautions, dose andstrength, see under Intravenous Adrenaline (Epinephrine),p. 160.On discharge, the child should be considered for furthertreatment with an oral antihistamine (section 3.4.1) andan oral corticosteroid (section 6.3.2) for up to 3 days toreduce the risk of further reaction. The child, or carer,should be instructed to return to hospital if symptomsrecur and to contact their general practitioner for followup.Children who are suspected of having had an anaphylacticreaction should be referred to a specialist forspecific allergy diagnosis. Avoidance of the allergen isthe principal treatment; if appropriate, an adrenalineauto-injector should be given or a replacement supplied(see Self-administration of Adrenaline, p. 160).Intramuscular adrenaline (epinephrine)The intramuscular route is the first choice route for theadministration of adrenaline in the management ofanaphylaxis. Adrenaline is best given as an intramuscularinjection into the anterolateral aspect of the middlethird of the thigh, it has a rapid onset of action afterintramuscular administration and in the shocked patientits absorption from the intramuscular site is faster andmore reliable than from the subcutaneous site. Theintravenous route should be reserved for extreme emergencywhen there is doubt about the adequacy of thecirculation; for details of cautions, dose and strength seeIntravenous Adrenaline (Epinephrine), p. 160.Children with severe allergy, and their carers, shouldideally be instructed in the self-administration of adrenalineby intramuscular injection (for details see Selfadministrationof Adrenaline (Epinephrine), p. 160).Prompt injection of adrenaline is of paramount importance.The following adrenaline doses are based on the3 Respiratory system