A 22-year-old man with asthma presents to accident and emergency acutely short of breath. He is unable to complete sentences in one breath and has bilateral expiratory wheeze on examination. Peak expiratory flow rate (PEFR) is 40% of his best. You suspect an acute exacerbation of asthma.

He has received oxygen-driven nebulised salbutamol back-to-back with nebulised ipratropium and 40mg oral prednisolone. Following this his PEFR is 45% best and he is still unable to complete sentences. He remains wheezy.

Which of the following is the best next step in the management of this patient?

Options:
explanation: Intramuscular adrenaline (1:1000) is part of the primary management of anaphylaxis. This patient is assumed to be having an acute severe exacerbation of asthma and so intramuscular adrenaline would not be indicated unless there were suspicion of anaphylaxis
name: Intramuscular adrenaline (1:1000)
label: c
answer: no
explanation: This patient is experiencing an acute severe exacerbation of his asthma. The next step in their management would be intravenous magnesium sulfate. Intravenous aminophylline is rarely used in acute severe exacerbation of asthma, and would only be considered in life-threatening exacerbations of impending respiratory failure after discussion with senior colleagues
name: Intravenous aminophylline
label: d
answer: no
explanation: This patient is experiencing an acute severe exacerbation of his asthma. Life-threatening asthma would be characterised by PEFR <33% best or one of: oxygen saturations <92%, altered consciousness, exhaustion, cardiac arrhythmia, hypotension, cyanosis, poor respiratory effort, silent chest, or confusion.

Management for acute severe exacerbation of asthma is: Oxygen, inhaled short acting bronchodilator (beta-2 agonist) driven by wet oxygen nebs, and corticosteroids e.g. oral prednisolone or intravenous hydrocortisone (same efficacy) for minimum 5 days or until recovery. If requires further therapy, then nebulised ipratropium which can be given back-to-back with salbutamol if not improving after 15-30 minutes of treatment. If the patient is still not improving, then you could consider IV magnesium sulfate over 20 minutes.

Other further management may include intravenous aminophylline and mechanical ventilation
name: Intravenous magnesium sulfate
label: a
answer: yes
explanation: This patient is experiencing an acute severe exacerbation of his asthma. He should be discussed with senior colleagues regarding next steps in management, where he will likely be given intravenous magnesium sulfate. If this were to fail, or the patient was more unwell and experiencing a life-threatening asthma exacerbation, then early consultation with critical care for consideration of mechanical ventilation is paramount. This is not required just yet as he is having an acute severe exacerbation with other treatment options available.

Kew KM, Kirtchuk L, Michell CI. Intravenous magnesium sulfate for treating adults with acute asthma in the emergency department. Cochrane Database of Systematic Reviews 2014, Issue 5. Art. No.: CD010909. DOI: 10.1002/14651858.CD010909.pub2
name: Intubation and mechanical ventilation
label: e
answer: no
explanation: Intravenous salbutamol can be considered if inhaled beta-2 agonist therapy cannot be used reliably. This patient shows no issues of tolerating nebulised salbutamol and therefore intravenous salbutamol would not be indicated
name: Intravenous salbutamol
label: b
answer: no

Correct answer: a