Management of Acute Severe Asthma with Bilateral Severe Wheeze
This patient requires immediate aggressive treatment with high-dose nebulized bronchodilators and systemic corticosteroids, along with objective assessment of severity using peak expiratory flow (PEF) measurement—bilateral severe wheeze indicates acute severe asthma that can be fatal if not recognized and treated appropriately. 1
Immediate Assessment and Examination
Assess severity objectively by measuring PEF immediately, as clinical assessment alone often underestimates severity 1:
- Severe asthma features: inability to complete sentences in one breath, respiratory rate >25/min, heart rate >110/min, PEF <50% predicted or personal best 1, 2
- Life-threatening features: PEF <33% predicted, silent chest, cyanosis, feeble respiratory effort, bradycardia, hypotension, exhaustion, confusion, or coma 1, 2
Check vital signs including oxygen saturation, respiratory rate, heart rate, and blood pressure 1
Examine for accessory muscle use, ability to speak, and willingness to recline (refusal to recline <30° suggests severe obstruction) 3
Immediate Treatment (Start AT ONCE)
High-Dose Inhaled Beta-Agonists
Administer salbutamol 5 mg or terbutaline 10 mg via oxygen-driven nebulizer immediately 1:
- Oxygen should be used as the driving gas (40-60%; CO₂ retention is not aggravated by oxygen in asthma) 1
- Alternative: 10-20 puffs of MDI with large spacer device if nebulizer unavailable 1
Systemic Corticosteroids
Give prednisolone 30-60 mg orally OR hydrocortisone 200 mg IV immediately 1:
- Do not delay—clinical benefits may not occur for 6-12 hours, so early administration is critical 3, 4
- Both can be given together if patient is very ill 1
Additional Therapy for Life-Threatening Features
If life-threatening features are present, add ipratropium 0.5 mg to the nebulizer 1
Consider IV aminophylline 250 mg over 20 minutes (but omit if patient already taking oral theophyllines) 1
Further Investigations
Measure PEF 15-30 minutes after initial treatment to assess response 1
Obtain arterial blood gas if severe or life-threatening features present 1:
- Normal or elevated PaCO₂ (5-6 kPa) in a breathless asthmatic indicates very severe, life-threatening attack 1
- Severe hypoxia (PaO₂ <8 kPa) despite oxygen treatment 1
- Low pH or high H⁺ 1
Chest radiograph to exclude pneumothorax, consolidation, or pulmonary edema 1
Plasma electrolytes, urea, and blood count; ECG in older patients 1
Pulse oximetry to maintain SaO₂ >92% 1
Subsequent Management Based on Response
If Patient Improving After 15-30 Minutes:
- Continue oxygen 40-60% 1
- Continue prednisolone 30-60 mg daily or IV hydrocortisone 200 mg every 6 hours 1
- Nebulized beta-agonist every 4 hours 1
If NOT Improving After 15-30 Minutes:
- Continue oxygen and steroids 1
- Increase nebulized beta-agonist frequency to every 15-30 minutes 1, 5
- Add ipratropium 0.5 mg to nebulizer, repeat 6-hourly until improvement 1, 3
- Note: Ipratropium benefits are primarily in the emergency setting and not sustained after hospital admission 3
Criteria for Hospital Admission
Immediate referral to hospital is required if: 1
- Any life-threatening features present 1
- Features of severe attack persist after initial treatment 1
- PEF remains <33% predicted 15-30 minutes after nebulization 1
Lower threshold for admission if patient seen in afternoon/evening, has recent nocturnal symptoms, previous severe attacks, concern about symptom assessment, or poor social circumstances 1
Common Pitfalls to Avoid
Never underestimate severity—bilateral severe wheeze with known asthma on medication suggests treatment failure and requires aggressive intervention 1, 2
Never give sedatives in acute asthma 1
Do not delay systemic corticosteroids—they should be given immediately, not after waiting to see response to bronchodilators 2, 3, 4
Avoid giving bolus aminophylline to patients already on oral theophyllines 1
Do not rely on clinical assessment alone—always measure PEF objectively, as severity is often underestimated 1