What is the initial management for a patient presenting to the emergency room (ER) with severe asthma, considering their past medical history and current medications?

Management of Severe Asthma in the Emergency Room

Immediately administer high-flow oxygen (40-60% via face mask or 15 L/min via reservoir mask if SpO₂ <85%), nebulized salbutamol 5 mg (or terbutaline 10 mg) via oxygen-driven nebulizer, and systemic corticosteroids (prednisolone 30-60 mg orally OR hydrocortisone 200 mg IV) within the first few minutes of arrival. 1, 2, 3

Initial Assessment

Upon arrival, rapidly identify features of severe versus life-threatening asthma to guide treatment intensity:

Severe asthma features: 4, 3

• Cannot complete sentences in one breath
• Respiratory rate >25/min
• Pulse >110 beats/min
• Peak expiratory flow (PEF) <50% of predicted or personal best

Life-threatening features: 4, 3

• Silent chest, cyanosis, or feeble respiratory effort
• Bradycardia or hypotension
• Exhaustion, confusion, drowsiness, or coma
• SpO₂ <92% despite oxygen therapy

Critical point: Patients with severe or life-threatening attacks may not appear distressed—the presence of any single feature should alert you to severity. 4 Physicians' subjective assessments are often inaccurate; objective measurement with PEF and pulse oximetry is essential. 3, 5

First-Line Treatment (First Hour)

Oxygen Therapy

• Target SpO₂ >90% (>95% in pregnant patients or those with heart disease) 1
• Use 40-60% oxygen via face mask or reservoir mask at 15 L/min if SpO₂ <85% 1, 2, 3
• Continue monitoring until clear response to bronchodilator therapy occurs 1

Bronchodilator Therapy

• Administer salbutamol 5 mg or terbutaline 10 mg via oxygen-driven nebulizer 4, 1, 2, 3
• Repeat every 20 minutes for 3 doses in the first hour 1, 2
• If no nebulizer available, give 2 puffs via large volume spacer and repeat (up to 20 puffs maximum) 4

Systemic Corticosteroids

• Give prednisolone 30-60 mg orally OR hydrocortisone 200 mg IV immediately 4, 1, 2, 3
• Do not delay corticosteroid administration—clinical benefits take 6-12 hours to manifest, and early administration (within 1 hour) significantly reduces hospitalization 1, 2, 5, 6
• Oral and IV routes are equally effective; there is no benefit to IV over oral administration 7

Reassessment at 15-30 Minutes

Measure PEF, assess symptoms, vital signs, and oxygen saturation after initial treatment: 1, 2

If PEF >75% predicted: 4

• Continue observation for 60 minutes
• Step up usual maintenance treatment
• Consider discharge if stable

If PEF 50-75% predicted: 4, 1

• Repeat nebulized beta-agonist
• Ensure prednisolone has been administered
• Wait 30 minutes and reassess

If PEF <50% predicted or severe features persist: 4, 1

• Proceed to second-line therapies
• Arrange hospital admission

Second-Line Therapies for Severe/Refractory Cases

Ipratropium Bromide

• Add ipratropium 0.5 mg to nebulized beta-agonist for severe exacerbations or inadequate response to initial therapy 4, 1, 3
• Reduces hospitalizations in moderate to severe exacerbations 7, 6

Intravenous Magnesium Sulfate

• Administer 2 g IV over 20 minutes for severe exacerbations 1, 8
• Significantly increases lung function and decreases hospitalization, particularly in children 7, 6
• Use early if likely to impact clinical course 9

Parenteral Beta-Agonists (Life-Threatening Cases)

• Consider subcutaneous terbutaline 250 µg over 10 minutes for life-threatening features 4, 1, 3
• Alternative: subcutaneous epinephrine in refractory cases 8, 5

Aminophylline (Life-Threatening Cases Only)

• Give 250 mg IV over 20 minutes for life-threatening exacerbations 4, 1, 3
• Caution: Use only if patient is not already taking theophylline preparations 4
• No role for routine use in acute asthma 9, 7

Critical Pitfalls to Avoid

Never administer sedatives of any kind—they are absolutely contraindicated in acute asthma 1, 8

Do not underuse corticosteroids—this is a common factor in preventable asthma deaths 4, 3

Do not give antibiotics unless bacterial infection (pneumonia/sinusitis) is confirmed 1

Exclude pneumothorax with chest radiography before giving aminophylline, especially in life-threatening cases 4

Criteria for Hospital Admission

Admit if any of the following persist after initial treatment: 4, 1, 2, 3

• Any life-threatening features present
• PEF <33% predicted after treatment
• Features of severe attack persist after 1-2 hours of intensive treatment
• PEF remains <50% predicted

ICU Transfer Criteria

Transfer immediately if: 2

• Deteriorating PEF despite treatment
• Worsening or persisting hypoxia (SpO₂ <92%)
• Hypercapnia on arterial blood gas
• Exhaustion, confusion, drowsiness, or altered mental status
• Silent chest or feeble respiratory effort

If patient is unconscious or confused: Call ICU/anesthesia immediately, arrange uninterrupted high-flow oxygen, and do not attempt intubation until the most expert available doctor (ideally an anesthetist) is present. 4

Discharge Considerations

Patients discharged from the ED need extra care—mortality is high in this group. 4 Before discharge, ensure: 4

• PEF >75% predicted and stable for 60 minutes
• Patient has adequate supply of medications
• Inhaler technique is correct
• Self-management plan is provided
• Follow-up arranged within 48 hours
• Contact patient's primary care physician during office hours