What is the initial treatment for status asthmaticus?

Initial Treatment for Status Asthmaticus

The initial treatment for status asthmaticus should include high-dose inhaled β-agonists (salbutamol 5-10 mg or terbutaline 10 mg), systemic corticosteroids (prednisolone 30-60 mg or IV hydrocortisone 200 mg), and oxygen therapy to maintain saturation 93-95%. 1

Assessment of Severity

Before initiating treatment, rapidly assess for features of severe or life-threatening asthma:

Severe Asthma Features:

• Too breathless to complete sentences in one breath
• Respiratory rate >25 breaths/min
• PEF <50% of predicted normal or best
• Heart rate >110 beats/min 2

Life-Threatening Features:

• PEF <33% of predicted normal or best
• Silent chest, cyanosis, or feeble respiratory effort
• Bradycardia or hypotension
• Exhaustion, confusion, or coma 2, 1

Step-by-Step Initial Management

1. Immediate Treatment (First 15-30 minutes)

• Oxygen: Administer high-flow oxygen (40-60%) via face mask to maintain SaO₂ >92% 1

  • Note: CO₂ retention is not aggravated by oxygen therapy in asthma 2

• High-dose inhaled β-agonists:

  • Salbutamol 5-10 mg or terbutaline 10 mg via oxygen-driven nebulizer
  • Can be repeated every 15-30 minutes as needed 1
  • Alternative: Multiple actuations of metered dose inhaler into a large spacer device (two puffs 10-20 times) 2

• Systemic corticosteroids:

  • Prednisolone 30-60 mg orally OR
  • IV hydrocortisone 200 mg (or both if very ill) 2, 1
  • Important: Administer corticosteroids as early as possible as clinical benefits may take 6-12 hours 3

2. Additional First-Line Measures for Life-Threatening Features

If life-threatening features are present, add:

• Ipratropium bromide: 0.5 mg nebulized (can be added to the β-agonist nebulizer) 2, 1
• Consider IV aminophylline (250 mg over 20 minutes) or IV salbutamol/terbutaline (250 μg over 10 minutes) 2
  • Caution: Do not give bolus aminophylline to patients already taking oral theophyllines 2

Monitoring Response to Initial Treatment

• Repeat PEF measurement 15-30 minutes after starting treatment 2, 1
• Continuous pulse oximetry to maintain SaO₂ >92% 1
• Arterial blood gas analysis if:
  • Initial PaO₂ <8 kPa (60 mm Hg)
  • PaCO₂ was normal or raised
  • Patient deteriorates 2

Subsequent Management (After Initial 30 Minutes)

If Improving:

• Continue oxygen therapy
• Continue prednisolone or IV hydrocortisone
• Continue nebulized β-agonist every 4-6 hours 2

If Not Improving:

• Continue oxygen and steroids
• Increase frequency of nebulized β-agonist (every 15-30 minutes)
• Add ipratropium 0.5 mg to nebulizer and repeat every 6 hours 2, 1

Criteria for Hospital Admission

Immediate referral to hospital is necessary for:

• Any life-threatening features
• Persistent severe attack features after initial treatment
• PEF <33% of predicted or best value 15-30 minutes after treatment 1

Common Pitfalls and Caveats

1. Underestimation of severity: The severity of asthma attacks is often underestimated by patients, relatives, and doctors due to failure to make objective measurements 2

2. Delayed corticosteroid administration: Corticosteroids should be given immediately as benefits may not be seen for 6-12 hours 3

3. Inadequate β-agonist dosing: During severe attacks, higher and more frequent doses are often required 1

4. Sedatives: Avoid sedatives in status asthmaticus as they can suppress respiratory drive 4

5. Antibiotics: Not routinely indicated unless there is evidence of bacterial infection 1

6. Magnesium sulfate: Consider IV magnesium sulfate as an adjunctive therapy in patients not responding to initial treatment, though evidence is mixed 4

By following this algorithm and avoiding common pitfalls, you can optimize outcomes in patients with status asthmaticus, reducing morbidity and mortality through prompt, aggressive treatment.