Acute Asthma Exacerbation Treatment
Begin immediate treatment with high-dose inhaled beta-agonists (salbutamol 5 mg or terbutaline 10 mg nebulized, or 4-8 puffs via MDI with spacer every 20 minutes), high-dose systemic corticosteroids (prednisolone 30-60 mg orally or hydrocortisone 200 mg IV), and supplemental oxygen to maintain SpO₂ >92%—delay in corticosteroid administration is a leading cause of preventable asthma deaths. 1, 2, 3
Initial Severity Assessment
Assess severity immediately using objective measurements, as clinical judgment alone is often inaccurate 3:
Severe Asthma Features (Adults)
- Unable to complete sentences in one breath 1
- Respiratory rate >25 breaths/min 1
- Heart rate >110 beats/min 1
- Peak expiratory flow (PEF) <50% predicted or personal best 1
Life-Threatening Features (Adults)
- PEF <33% predicted or personal best 1
- Silent chest, cyanosis, or feeble respiratory effort 1
- Bradycardia, hypotension, exhaustion, confusion, or coma 1
- Normal or elevated PaCO₂ (5-6 kPa) in a breathless patient 1
- Severe hypoxia: PaO₂ <8 kPa despite oxygen 1
Severe Asthma Features (Children)
- Too breathless to talk or feed 1
- Respiratory rate >50 breaths/min 1, 4
- Heart rate >140 beats/min 1, 4
- PEF <50% predicted 1
Life-Threatening Features (Children)
- PEF <33% predicted 1, 2
- Silent chest, poor respiratory effort, cyanosis 1, 2
- Exhaustion, agitation, or reduced consciousness 1, 2
Common pitfall: Patients, relatives, and physicians frequently underestimate severity by failing to obtain objective measurements—always measure PEF and oxygen saturation 1
Immediate Management Protocol
Adults
Start all three interventions simultaneously 1:
High-dose inhaled beta-agonists: Salbutamol 5 mg or terbutaline 10 mg via oxygen-driven nebulizer, OR 10-20 puffs (2 puffs repeated 10-20 times) via MDI with large spacer 1, 5
High-dose systemic corticosteroids: Prednisolone 30-60 mg orally OR hydrocortisone 200 mg IV (or both) 1
Supplemental oxygen: High-flow oxygen (40-60%) to maintain SpO₂ >92% 1
If life-threatening features present, add immediately 1:
- Ipratropium bromide 0.5 mg nebulized with beta-agonist 1
- IV aminophylline 250 mg over 20 minutes (omit if patient already taking oral theophyllines) OR IV salbutamol/terbutaline 250 µg over 10 minutes 1
Children
Start all interventions simultaneously 1, 2:
High-dose inhaled beta-agonists: Salbutamol 5 mg via oxygen-driven nebulizer (half dose in very young children), OR 4-8 puffs via MDI with spacer every 20 minutes 1, 2
Systemic corticosteroids: Prednisolone 1-2 mg/kg orally (maximum 40 mg) OR IV hydrocortisone 1, 2
Supplemental oxygen: High-flow oxygen via face mask to maintain SpO₂ >92% 1, 2
Ipratropium bromide: 100-250 mcg nebulized with each salbutamol dose for first hour, then every 6 hours 1, 2
If life-threatening features present, add 1:
- IV aminophylline 5 mg/kg over 20 minutes, then 1 mg/kg/hour maintenance (omit loading dose if already on oral theophyllines) 1
- Consider IV magnesium sulfate 2, 6
Pregnant Patients
Treat identically to non-pregnant adults—maternal hypoxia poses greater fetal risk than medications 1:
- Use same beta-agonist, corticosteroid, and oxygen protocols 1
- Pregnant women with worsening asthma require specialist referral 1
Reassessment at 15-30 Minutes
Measure PEF and reassess clinical status 15-30 minutes after initial treatment 1, 2:
If Improving (Adults)
- Continue high-flow oxygen 1
- Continue prednisolone 30-60 mg daily 1
- Continue nebulized beta-agonist every 4 hours 1
- Monitor PEF every 15-30 minutes initially 1
If NOT Improving After 15-30 Minutes (Adults)
- Continue oxygen and steroids 1
- Increase nebulized beta-agonist frequency to every 30 minutes 1
- Add ipratropium 0.5 mg to nebulizer every 6 hours 1
- Obtain arterial blood gas if PaO₂ <8 kPa, PaCO₂ normal/elevated, or patient deteriorating 1
If Improving (Children)
- Continue high-flow oxygen 1
- Continue prednisolone 1-2 mg/kg daily (maximum 40 mg) 1
- Continue nebulized beta-agonist every 4 hours 1
If NOT Improving After 15-30 Minutes (Children)
- Continue oxygen and steroids 1
- Increase nebulized beta-agonist to every 30 minutes 1
- Continue ipratropium every 6 hours 1
Hospital Admission Criteria
- Any life-threatening features present 1
- Features of severe asthma persist after initial treatment 1
- PEF remains <50% predicted after treatment 2, 7
- SpO₂ <92% despite treatment 2
Lower threshold for admission if 1:
- Attack occurs in afternoon/evening 1
- Recent nocturnal symptoms or hospital admission 1
- Previous severe attacks or ICU admissions 1
- Poor social circumstances or inability to assess own condition 1
ICU Transfer Criteria
Transfer to ICU with physician prepared to intubate if 1:
- Deteriorating PEF despite treatment 1
- Worsening or persistent hypoxia 1
- Exhaustion, feeble respirations, confusion, drowsiness 1
- Coma or respiratory arrest 1
Discharge Criteria
Patients may be discharged when 1, 2:
- On discharge medications for 24 hours with verified inhaler technique 1
- PEF >75% predicted or personal best 1
- PEF diurnal variability <25% 1
- SpO₂ stable >92% on room air 2
- Oral corticosteroid course for 3-10 days (prednisolone 30-60 mg daily adults; 1-2 mg/kg children) 2, 7
- Inhaled corticosteroid controller therapy initiated or continued 1, 2
- Written self-management plan provided 1, 7
- Peak flow meter provided (if appropriate) 1
- GP follow-up within 1 week 1
- Respiratory clinic follow-up within 4 weeks 1
Critical Management Pitfalls
Avoid these common errors that contribute to asthma mortality 1, 2:
- Delaying systemic corticosteroids while giving repeated bronchodilators alone—underuse of corticosteroids is a leading cause of preventable deaths 1, 2
- Failing to obtain objective measurements (PEF, SpO₂)—subjective assessment consistently underestimates severity 1, 3
- Discharging patients too early—airway inflammation persists for days to weeks after acute symptoms resolve 6, 7
- Not addressing underlying poor control—exacerbations indicate inadequate maintenance therapy requiring step-up 5, 8, 7