Case one:

Luke, aged 3 years, has a past history of frequent episodic asthma. He presents with an acute exacerbation of his asthma. He developed a runny nose, cough and fever 24 hours previously and began wheezing in the past 12 hours. His mother, Julie, has an asthma plan and started him on 6 puffs of Ventolin every 3-4 hours. In the past hour Luke has deteriorated and the last dose of Ventolin seemed to have not made any difference. Julie has run out of prednisolone. Luke has been using an asthma preventer for the past 6 months (Seretide 50: 2 puffs twice per day). He has had two previous hospital admissions in the past 6 months; the last one 6 weeks ago. He is otherwise well controlled and has no interval symptoms (no night or early morning cough or wheeze, and has not missed kindergarten in the past 6 weeks).

Examination shows Luke has a temperature of 39⁰C and a pulse rate of 140. He is able to speak in sentences, has nasal flaring, a hyperinflated chest with moderate intercostal and suprasternal recession. He has an audible wheeze and on auscultation he has generalised wheeze with decreased air entry on the right base. He last had Ventolin (6 puffs) 45 minutes ago.

Answer 1
Luke has moderate asthma (Table 1). He has signs indicating moderate work of breathing, but is able to talk in full sentences. He has a generalised wheeze, with focal decreased air entry. His mental status is normal.

Answer 2
Initial management would be 6 puffs of Ventolin via a spacer (or a 5 mg nebule in a nebuliser). The latter has not been shown to be better than a spacer.⁵ In this setting, Luke requires a firm fitting mask on the spacer to deliver the Ventolin. If possible, also give 2 puffs of ipratropium bromide after the Ventolin. If there is a response, then both medications can be repeated every 20 minutes for a total of 3 doses. A dose of 1mg/kg of oral prednisolone should be given after the first dose of Ventolin. If there is no response to the first dose, an ambulance should be called and Ventolin given every 10 minutes either via a spacer or nebuliser until the ambulance arrives. Oral prednisolone should also be given.

Answer 3
Luke does not require a CXR. His asymmetrical air entry is due to mucus plugging which will clear eventually. A CXR should only be performed in severe or critical asthma when there is a suspicion of pneumothorax or pneumomediastinum. If an X-ray was performed, the likely finding will be abnormal as areas of atelectasis will be present and misinterpreted as pneumonia.

Answer 4
Luke's progress should be determined by:

• decreased work of breathing
• less intercostal and suprasternal retraction
• decreased respiratory rate
• decreased wheeze on auscultation with concomitant increase in air entry
• improvement in mental status if affected beforehand.

Luke needs a period of observation to determine when his next dose of Ventolin is required. If after 1 hour of observation Luke is wheeze free (or has minimal wheeze), then sending him home is appropriate, with Ventolin given every 3-4 hours.

If Luke resumes wheezing within the next hour or deteriorates, he should be referred to hospital.

Answer 5
If Luke requires Ventolin more frequently than every 2 hours, he should re-present to you or the hospital emergency department. Prednisolone should be prescribed at 1 mg/kg for 3 days. Luke's asthma action plan should also be checked and updated if required. A telephone or clinical review should be arranged for the next day.

Patients should be instructed to continue 6 puffs of Ventolin for each dose until they require Ventolin every 4-6 hours, at which time, the amount of puffs can be reduced.

Answer 6
Luke does not require antibiotics. He has a viral upper respiratory tract infection which has triggered his asthma. Despite having a fever, his decreased air entry is due to mucus plugging not pneumonia.