Management of acute asthma in adults in the emergency department

Measure peak expiratory flow and arterial saturations

PEF >50–75% best or predicted

Moderate asthma

PEF 33–50% best or predicted

Acute severe asthma

PEF <33% best or predicted

Life-threatening asthma

Give β₂ bronchodilator via spacer (give one puff at a time; according to response, give another puff every 60 seconds up to maximum of 10 puffs)

Give β₂ bronchodilator (salbutamol 5mg) by oxygen-driven nebuliser

Obtain senior/ICU help now if any life-threatening features are present

Immediate management

• Oxygen to maintain SpO₂ 94–98%
• β₂ bronchodilator with ipratropium - via nebuliser (preferably oxygen-driven), salbutamol 5mg and ipratropium 0.5 mg
• Prednisolone 40–50mg orally or IV hydrocortisone 100mg

Measure arterial blood gases

Markers of severity:

• ‘Normal’ or raised PaCO₂ (PaCO₂ >4.6 kPa; 35 mmHg)
• Severe hypoxia (PaO2 <8 kPa; 60 mmHg)
• Low pH (or high H+)

• Give/repeat salbutamol 5mg with ipratropium 0.5 mg by oxygen-driven nebuliser after 15 minutes
• Consider continuous salbutamol nebuliser 5–10mg/hr
• Consider IV magnesium sulphate 1.2–2g over 20 minutes
• Correct fluid/electrolytes, especially K⁺ disturbances
• Chest X-ray
• Repeat ABG

Admit

Patient accompanied by a nurse or doctor at all times

Life threatening features OR PEF <50%?

Clinically stable AND PEF <75%?

Repeat salbutamol 5mg nebuliser

Give prednisolone 40–50mg orally

Signs of severe asthma OR PEF <50%?

Patient recovering AND PEF >75%?

Immediate management

• Oxygen to maintain SpO₂ 94–98%
• β₂ bronchodilator with ipratropium - via nebuliser (preferably oxygen-driven), salbutamol 5mg and ipratropium 0.5 mg
• Prednisolone 40–50mg orally or IV hydrocortisone 100mg

Signs of severe asthma OR PEF <50%?

Potential discharge

• In all patients who received nebulised β₂ bronchodilator prior to presentation, consider an extended observation period prior to discharge
• If PEF<50% on presentation, give prednisolone 40–50 mg/day until recovery (minimum 5 days) In all patients ensure treatment supply of inhaled steroid and β₂ bronchodilator and check inhaler technique
• Arrange GP follow up within 2 working days post discharge
• Fax or email discharge letter to GP
• Refer to asthma liaison nurse/chest clinic