Acute severe asthma in adults

Acute severe asthma represents a common medical emergency accounting for over 75,000 UK hospital admissions each year and asthma still accounts for approximately 1500 UK deaths annually. Risk factors for fatal asthma include poorly controlled disease, inappropriate medical management, and adverse behavioural and social factors. Asthma is characterized by chronic airways inflammation, resulting in periodic wheeze, cough and breathlessness. A variety of triggers can precipitate an exacerbation; viral respiratory tract infections are the most common. Exacerbations are identified by an increase in asthma symptoms and fall in lung function. National and international acute asthma management guidelines highlight best practice. All patients presenting with poorly controlled asthma symptoms should be examined and peak expiratory flow (PEF) or forced expiratory volume in 1 second (FEV1) recorded. Patients with a PEF less than 50% of baseline/predicted have a severe exacerbation and should be referred to hospital. Treatment aims to rapidly relieve bronchoconstriction and halt airways inflammation; oxygen, systemic corticosteroids and inhaled bronchodilators represent first-line treatments. Patients with features of life-threatening asthma should receive magnesium sulphate and be discussed with intensive care. Prior to discharge, patients’ medications should be reviewed, asthma self-management plan agreed and early follow-up should be arranged.