What is the immediate treatment for an asthma exacerbation?

Immediate Treatment for Asthma Exacerbation

For any asthma exacerbation, immediately administer oxygen to maintain saturation >90% (>95% in pregnancy or heart disease), give albuterol 2.5-5 mg via nebulizer or 4-8 puffs via MDI with spacer every 20 minutes for 3 doses, and administer oral prednisone 40-60 mg (adults) or 1-2 mg/kg/day up to 60 mg (children) within the first 15-30 minutes. 1, 2

Initial Assessment and Oxygen Therapy

• Assess severity immediately using inability to complete sentences in one breath, respiratory rate >25 breaths/min, heart rate >110 beats/min, and peak expiratory flow (PEF) <50% predicted for severe exacerbation 1
• Life-threatening features include PEF <33% predicted, silent chest, cyanosis, altered mental status, or PaCO₂ ≥42 mmHg 1, 3
• Administer supplemental oxygen through nasal cannula or mask immediately to maintain oxygen saturation >90% (>95% in pregnant patients or those with heart disease) 1, 2, 3
• Monitor oxygen saturation continuously until clear response to bronchodilator therapy occurs 1, 2

Primary Bronchodilator Therapy

• Albuterol is first-line treatment for all asthma exacerbations regardless of severity 1, 2, 3
• Nebulizer dosing: 2.5-5 mg every 20 minutes for 3 doses, then 2.5-10 mg every 1-4 hours as needed 1, 2, 4
• MDI with spacer dosing: 4-8 puffs every 20 minutes for up to 3 doses, then as needed 1, 2
• For severe exacerbations (PEF <40%), consider continuous nebulization of albuterol rather than intermittent dosing 2, 3
• The flow rate should deliver albuterol over approximately 5 to 15 minutes 4

Systemic Corticosteroids - Critical Early Intervention

• Administer systemic corticosteroids immediately within the first 15-30 minutes for all moderate to severe exacerbations 1, 2, 3
• Adult dosing: Prednisone 40-60 mg orally in single or divided doses 1, 2
• Pediatric dosing: 1-2 mg/kg/day (maximum 60 mg/day) 1, 2
• Oral administration is as effective as IV and should be preferred unless the patient cannot tolerate oral medications 1
• Alternative for severe cases: IV methylprednisolone 125 mg or IV hydrocortisone 200 mg 1, 3
• Duration: 5-10 days for outpatient therapy with no taper needed for courses <10 days 1

Adjunctive Ipratropium Bromide

• Add ipratropium bromide to albuterol for all moderate to severe exacerbations 1, 2, 3
• Dosing: 0.5 mg via nebulizer or 8 puffs via MDI every 20 minutes for 3 doses, then as needed 1, 2, 3
• This combination reduces hospitalizations, particularly in patients with severe airflow obstruction 1

Reassessment Protocol

• Reassess at 15-30 minutes after starting treatment by measuring PEF or FEV₁, assessing symptoms, and checking vital signs 1, 2, 3
• Reassess again at 60-90 minutes after the initial 3 doses of bronchodilator 1
• Response to treatment is a better predictor of hospitalization need than initial severity 1, 2

Severe or Refractory Cases

• Consider IV magnesium sulfate 2 g over 20 minutes for severe exacerbations (FEV₁ or PEF <40%) not responding to initial therapy or with life-threatening features 1, 2, 3
• Pediatric magnesium dosing: 25-75 mg/kg up to 2 g maximum IV over 20 minutes 1
• Magnesium is most effective when administered early in the treatment course 2

Critical Pitfalls to Avoid

• Never delay corticosteroid administration - do not wait to "try bronchodilators first" 1
• Never administer sedatives of any kind to patients with acute asthma 1, 2
• Do not underestimate severity - patients, families, and clinicians frequently fail to recognize dangerous exacerbations due to inadequate objective measurements 1
• Avoid theophylline/aminophylline due to increased side effects without superior efficacy 1
• Monitor for hypokalemia with repeated albuterol dosing, though supplementation is rarely needed 4
• Do not delay intubation once deemed necessary - perform semi-electively before respiratory arrest 1

Hospital Admission Criteria

• Immediate hospital referral required for: life-threatening features (confusion, drowsiness, silent chest, cyanosis, PEF <33%), or features of severe attack persisting after initial treatment 1, 3
• Lower threshold for admission if patient presents afternoon/evening, has recent nocturnal symptoms, previous severe attacks, or poor social circumstances 1
• Consider ICU admission for PEF <33% predicted, silent chest, altered mental status, or minimal relief from frequent albuterol 1