A WHEEZY TEENAGER
History
Bradley is a 13-year-old boy who is seen in the A&E department at the request of the GP out-of-hours service. He is a known asthmatic and this is his third attendance with an acute wheeze in 3 months. His mother reports that last time he was nearly transferred to the paediatric intensive care unit (PICU). He has developed a cold and become acutely breathless and is using his salbutamol inhaler hourly without much relief. The accompanying letter says that he is prescribed a beclometasone metered dose inhaler (MDI) 100 µg/metered inhalation 2 puffs b.d., salmeterol MDI 50 µg/metered inhalation 1 puff b.d. and salbutamol MDI 100 µg/metered inhalation p.r.n.
Examination Bradley is sitting up in bed with a nebulizer in progress containing 5 mg salbutamol. His oxygen saturation on 15 L of oxygen on arrival is documented as 89 per cent. He is quiet but able to answer questions with short sentences. His chest is hyperinflated (increased anteroposterior diameter) and he is using his accessory muscles of respiration. His respiratory rate is 60 breaths/min and he has marked tracheal tug with intercostal and subcostal recession. On auscultation there is equal but poor air entry with widespread expiratory wheeze. His temperature is 37.6C. His pulse is 180 beats/min with good perfusion. Questions
• What is the most likely underlying cause for this acute episode?
• What signs would you look for of impending respiratory failure?
• Outline your management plan for this acute episode
• What should happen before he is discharged?
Medicine
This boy has another acute exacerbation of asthma. Much the most likely underlying cause is poor adherence to home treatment. This is common in all age groups but particularly in teenagers with their growing independence and risk-taking behaviour.
Signs of impending respiratory failure
• Exhaustion (this is a clinical impression)
• Unable to speak or complete sentences
• Colour – cyanosis pallor
• Hypoxia despite high-flow humidified oxygen
• Restlessness and agitation are signs of hypoxia, especially in small children
• Silent chest – so little air entry that no wheeze is audible
• Tachycardia
• Drowsiness
• Peak expiratory flow rate (PEFR) persistently 30 per cent of predicted for height (tables are available) or personal best. Children 7 years cannot perform PEFR reliably and technique in sick children is often poor
Acute management goals are to correct hypoxia, reverse airway obstruction and prevent progression. Reassurance and calm are crucial because he will be frightened. Give high-flow oxygen via mask and monitor saturations. Start a regular inhaled β-agonist (e.g. salbutamol) via a nebulizer. Beta-agonists can be given continuously. If so, cardiac monitoring is needed as side-effects include irritability, tremor, tachycardia and hypokalaemia. Inhaled ipratropium bromide can be added. Give oral prednisolone or intravenous (IV) hydrocortisone. Frequent clinical review is paramount. Blood gases (capillary or venous) and a chest X-ray may be required. If there is no improvement or the child deteriorates, additional treatment is needed. These include IV salbutamol, IV magnesium sulphate (a smooth muscle relaxant) and IV aminophylline, although the effectiveness of the latter two is still controversial. His precipitating ‘cold’ is almost certainly viral and antibiotics are unlikely to be beneficial. Before discharge a thorough review of his asthma is needed:
• How often does he miss his regular drugs?
• Is there parental supervision?
• What device does he use? Children rarely use MDIs effectively and need a spacer. However, he is unlikely to use one because they are cumbersome and not ‘cool’. Agree an alternative ‘breath-activated’ device with the proviso that, if acutely wheezy, he must use a spacer.
• Consider changing to a combined steroid/long-acting β-agonist inhaler. This should improve adherence.
• Ask about smoking – him and his family. Adults should be encouraged to stop smoking or to smoke outside.
• Educate about allergen avoidance, e.g. daily vacuuming to reduce house dust mites. Consider measuring total IgE and specific allergen IgE (RAST) if the history suggests allergies.
• All asthmatics should have a written home management plan.
• Provide an asthma symptom diary and arrange hospital follow-up until control improves. Most children can and should be managed in primary care. Primary care and hospital-based asthma specialist nurses are very helpful.
KEY POINTS
• The commonest cause of an acute deterioration in chronic asthma is poor adherence to treatment.
• Home management should be reviewed during any acute admission.
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