Treatment for Acute Status Asthmaticus
The treatment for acute status asthmaticus requires immediate administration of high-flow oxygen (40-60%), nebulized beta-agonists (salbutamol/albuterol 5 mg or terbutaline 10 mg), nebulized ipratropium bromide 0.5 mg, and systemic corticosteroids (prednisolone 30-60 mg orally or hydrocortisone 200 mg intravenously). 1, 2
Initial Assessment and Management
Recognition of Acute Status Asthmaticus
Identify the following features:
- Too breathless to talk or complete sentences
- Respiratory rate >25 breaths/min (adults) or >50 breaths/min (children)
- Heart rate >110 beats/min (adults) or >140 beats/min (children)
- Peak expiratory flow (PEF) <50% of predicted or best
- Use of accessory muscles of respiration
- Oxygen saturation <92% 1
Life-threatening Features
- PEF <33% of predicted or best
- Silent chest, cyanosis, poor respiratory effort
- Fatigue, exhaustion, or altered consciousness
- Hypoxemia despite oxygen therapy
- Rising PaCO2 1
Immediate Treatment Algorithm
Oxygen Therapy:
Bronchodilator Therapy:
Anti-inflammatory Therapy:
Anticholinergic Therapy:
- Add ipratropium bromide 0.5 mg to nebulizer
- Repeat every 6 hours until improvement begins 1
Subsequent Management
If Patient Is Improving:
- Continue oxygen therapy
- Continue prednisolone 30-60 mg daily or IV hydrocortisone 200 mg every 6 hours
- Continue nebulized beta-agonist every 4-6 hours 1
If Patient Is Not Improving After 15-30 Minutes:
- Continue oxygen and steroids
- Increase frequency of nebulized beta-agonist (up to every 15-30 minutes)
- Ensure ipratropium bromide is added to nebulizer and repeated every 6 hours 1
If Still Not Improving:
- Consider IV aminophylline infusion (750-1500 mg/24 hours based on patient size)
- OR consider salbutamol/terbutaline infusion as an alternative
- Consider IV magnesium sulfate (2 g over 20 minutes) for severe refractory cases 1, 2
Monitoring Treatment
- Repeat PEF measurement 15-30 minutes after starting treatment
- Monitor oxygen saturation continuously (maintain >92%)
- Chart PEF before and after bronchodilator treatment and at least 4 times daily
- Assess heart rate, respiratory rate, and work of breathing 1
Indications for ICU Transfer
Transfer to intensive care unit (accompanied by a doctor prepared to intubate) if:
- Deteriorating PEF despite maximal therapy
- Persistent or worsening hypoxemia
- Hypercapnia (rising PaCO2)
- Exhaustion, confusion, drowsiness
- Respiratory arrest or coma 1, 5
Discharge Criteria
Patients should only be discharged when:
- They have been on discharge medication for 24 hours
- Inhaler technique has been checked and recorded
- PEF >75% of predicted or best and PEF diurnal variability <25%
- Treatment plan includes oral steroids and inhaled steroids
- Patient has own PEF meter and written self-management plan
- Follow-up with GP arranged within 1 week
- Follow-up in respiratory clinic within 4 weeks 1, 2
Important Considerations and Pitfalls
- Avoid sedatives of any kind in acute severe asthma as they can cause respiratory depression 1
- Obtain a chest radiograph to exclude pneumothorax, which can complicate severe asthma 1
- Do not give bolus aminophylline to patients already taking oral theophyllines unless subsequent monitoring of levels is planned 1
- Recognize that clinical assessment alone may underestimate severity; objective measures (PEF, oxygen saturation) are essential 6, 4
- Beware of the silent chest - this indicates very severe airflow limitation, not improvement 1, 4
- Consider mechanical ventilation if there is deteriorating PEF, worsening exhaustion, confusion, drowsiness, or respiratory arrest 5, 7
The cornerstone of effective management is early recognition, aggressive bronchodilator therapy, early administration of systemic corticosteroids, and close monitoring of response to treatment 4, 8.