BNF for Children 2011-2012

134 3.1 Bronchodilators BNFC 2011–20123 Respiratory systemasthma should preferably be administered by inhalationto minimise fetal drug exposure. Inhaled drugs, theophylline,and prednisolone can be taken as normalduring pregnancy and breast-feeding. Women planningto become pregnant should be counselled about theimportance of taking their asthma medication regularlyto maintain good control.Severe acute exacerbations of asthma can have anadverse effect on pregnancy and should be treatedpromptly in hospital with conventional therapy, includingnebulisation of a beta 2 agonist, and oral or parenteraladministration of a corticosteroid; prednisoloneis the preferred corticosteroid for oral administrationsince very little of the drug reaches the fetus. Oxygenshould be given immediately to maintain an arterialoxygen saturation of 94–98% and prevent maternaland fetal hypoxia. An intravenous beta 2 agonist, aminophylline,or magnesium sulphate can be used duringpregnancy if necessary; parenteral beta 2 agonists canaffect the myometrium, see BNF section 7.1.3.Management of acute asthma 1ImportantRegard each emergency consultation as being forsevere acute asthma until shown otherwise.Failure to respond adequately at any time requiresimmediate transfer to hospital.Severe acute asthma can be fatal and must be treatedpromptly. Treatment of severe acute asthma is safer inhospital where resuscitation facilities are immediatelyavailable. Treatment should never be delayed for investigations,children should never be sedated, and thepossibility of a pneumothorax should be considered. Ifthe child’s condition deteriorates despite pharmacologicaltreatment, urgent transfer to a paediatric intensivecare unit should be arranged. For a table outliningthe management of severe acute asthma, see Managementof acute asthma p. 136.Mild to moderate acute asthma Administer ashort-acting beta 2 agonist using a pressurisedmetered-dose inhaler with a spacer device; for a childunder 3 years use a close-fitting facemask. Give 1 puffevery 15–30 seconds up to a maximum of 10 puffs;repeat dose after 10–20 minutes if necessary.Give prednisolone by mouth, child under 12 years 1–2 mg/kg (max. 40 mg) once daily for up to 3 days, orlonger if necessary; if the child has been taking an oralcorticosteroid for more than a few days, give prednisolone2 mg/kg (max. 60 mg) once daily. For children 12–18 years, give prednisolone 40–50 mg daily for at least 5days.1. Advice on the management of acute asthma is based onthe recommendations of the British Thoracic Society andScottish Intercollegiate Guidelines Network (updated June2009); updates available at www.brit-thoracic.org.ukIf response is poor or if a relapse occurs within 3–4hours, transfer child immediately to hospital for assessmentand further treatment.Children under 18 months often respond poorly tobronchodilators; nebulised beta 2 agonists have beenassociated with mild (but occasionally severe) paradoxicalbronchospasm and transient worsening of oxygensaturation; response to prednisolone may also be poorin this age group.Severe or life-threatening acute asthma Starttreatment below and transfer immediately to hospital.Administer high-flow oxygen (section 3.6) using a closefittingface mask or nasal prongs.Treat severe or life-threatening acute exacerbations ofasthma with an inhaled short-acting beta 2 agonist (asabove). Treatment of life-threatening asthma should beinitiated with nebulised salbutamol 2.5 mg or terbutaline5 mg (via an oxygen-driven nebuliser if available); nebuliseddoses may be doubled for children over 5 years.Repeat the dose every 20–30 minutes or as necessary,then reduce the frequency on improvement.Give prednisolone by mouth, child under 12 years 1–2 mg/kg (max. 40 mg) once daily for up to 3 days, orlonger if necessary; if the child has been taking an oralcorticosteroid for more than a few days, give prednisolone2 mg/kg (max. 60 mg) once daily. For children 12–18 years, give prednisolone 40–50 mg daily for at least 5days. If oral administration is not possible, use intravenoushydrocortisone (preferably as sodium succinate)4 mg/kg (max. 100 mg) (alternatively, if weightunavailable, child under 2 years 25 mg, 2–5 years50 mg, 5–18 years 100 mg) every 6 hours.If response is poor, add nebulised ipratropiumbromide, child under 12 years give 250 microgramsevery 20–30 minutes for the first 2 hours, then every4–6 hours as necessary. For children 12–18 years, giveipratropium bromide 500 micrograms every 4–6 hoursas necessary.If the condition does not respond or is life-threatening,transfer the child to an intensive care unit and treat withagonist (e.g. salbut-a parenteral short-acting beta 2amol, section 3.1.1.1) or parenteral aminophylline (section3.1.3). Children over 2 years with severe acuteasthma may be helped by intravenous infusion ofmagnesium sulphate 40 mg/kg (max. 2 g) over 20minutes (section 9.5.1.3), but evidence of benefit islimited.Follow-up in all cases Episodes of acute asthmashould be regarded as a failure of preventive therapy. Acareful history should be taken to establish the reasonfor the exacerbation. Inhaler technique should bechecked and regular treatment should be reviewed inaccordance with the Management of Chronic Asthmatable, p. 135. Children or their carers should be given anasthma action plan aimed at preventing relapse, optimisingtreatment, and preventing delay in seeking assistancein future exacerbations. If possible, follow-upwithin 48 hours should be arranged with the generalpractitioner or appropriate primary care health professional.Children should also be reviewed in a paediatricasthma clinic within 1–2 months of the exacerbation.