Treatment for Asthma Exacerbation
The treatment for asthma exacerbation should include immediate administration of short-acting beta-agonists, early systemic corticosteroids, and oxygen therapy, with severity-based escalation of care including anticholinergics, magnesium sulfate, and consideration of ICU transfer for severe cases. 1, 2
Assessment and Classification
Asthma exacerbations should be classified based on severity to guide treatment decisions:
| Classification | Symptoms | PEF Value |
|---|---|---|
| Mild | Mild symptoms, no limitation of activities | ≥80% of predicted or personal best |
| Moderate | Worsening symptoms, some limitation | 50-79% of predicted or personal best |
| Severe | Significant symptoms, significant limitation | <50% of predicted or personal best |
| Life-threatening | Severe symptoms, inability to speak, cyanosis | <25% of predicted or personal best |
Key assessment parameters:
- Peak Expiratory Flow (PEF) measurement 15-30 minutes after starting treatment
- Oxygen saturation
- Ability to speak in full sentences
- Use of accessory muscles
- Heart rate and respiratory rate
First-Line Treatment
1. Oxygen Therapy
- Administer oxygen through nasal cannulae or mask to maintain SaO₂ >90% (>95% in pregnant women and patients with heart disease) 2
- Oxygen should be provided to all patients with severe asthma, even those with normal oxygenation 1
2. Short-Acting Beta-Agonists (SABA)
- Administer nebulized albuterol (salbutamol) every 20 minutes for the first hour 1
- For severe exacerbations, consider continuous nebulization rather than intermittent administration 1
- Metered-dose inhalers with spacers are as effective as nebulizers when used correctly 1
- Increase frequency (up to every 15-30 minutes) for severe exacerbations 2
3. Systemic Corticosteroids
- Administer within the first hour of treatment 2
- For adults: Methylprednisolone 125 mg IV (range 40-250 mg) or dexamethasone 10 mg IV 1
- Alternatively: Prednisolone 30-60 mg orally 2
- Oral and IV formulations have similar clinical effects, but IV route is preferable in severe asthma 1
- Continue prednisolone 30-60 mg daily for typically 7 days (may need up to 21 days) 2
Adjunctive Therapies
1. Anticholinergics
- Add ipratropium bromide 0.5 mg via nebulizer every 6 hours until improvement begins 2
- Particularly beneficial in patients with severe exacerbations 1
- Reduces hospital admissions when combined with beta-agonists 1
2. Magnesium Sulfate
- Consider IV magnesium sulfate (2g over 20 minutes) for patients with severe refractory asthma 1
- Improves pulmonary function and reduces hospital admissions in severe exacerbations 1
3. Epinephrine/Terbutaline
- Consider subcutaneous epinephrine (0.01 mg/kg, divided into 3 doses of ~0.3 mg at 20-minute intervals) for acute severe asthma 1
Escalation of Care
Transfer to intensive care if the patient has:
- Deteriorating PEF despite treatment
- Persistent or worsening hypoxia
- Hypercapnia
- Exhaustion, confusion, drowsiness
- Respiratory arrest 2
Common Pitfalls to Avoid
Delaying corticosteroid administration - Systemic corticosteroids should be given early as their anti-inflammatory effects may not be apparent for 6-12 hours 1, 2
Underestimating severity based on clinical appearance alone - Use objective measures like PEF and oxygen saturation 2
Using sedatives - Sedatives of any kind are contraindicated in asthma exacerbations 2
Substituting inhaled corticosteroids for systemic corticosteroids - In more severe exacerbations, oral corticosteroids are significantly more effective than inhaled corticosteroids 3
Relying on IV beta-agonists - Systematic reviews show that IV beta-agonists do not lead to significant improvements in clinical outcomes 1
Discharge Criteria and Follow-up
Discharge patients when:
- Symptoms have stabilized
- PEF above 75% of predicted value or personal best
- Minimal or absent symptoms
- Stable response to bronchodilator therapy for 60 minutes 2
Discharge planning should include:
- Oral corticosteroids (typically 7-day course)
- Continued SABA as needed
- Written asthma action plan
- Follow-up appointment within 1 week
- Review of inhaler technique 2
Remember that montelukast and omalizumab are not indicated for acute asthma exacerbations 4, 5. Montelukast specifically states that it "is not indicated for use in the reversal of bronchospasm in acute asthma attacks, including status asthmaticus" 5.