What standing doses of medications should be administered for an adult asthma exacerbation?

Standing Doses for Adult Asthma Exacerbation

For an adult asthma exacerbation, immediately administer nebulized albuterol 2.5-5 mg every 20 minutes for 3 doses, oral prednisone 40-60 mg as a single dose, and supplemental oxygen to maintain SpO₂ >90%. 1, 2

Initial Assessment and Severity Stratification

Before initiating treatment, quickly assess severity using objective measures rather than clinical impression alone, as physicians' subjective assessments are often inaccurate 3:

• Moderate exacerbation: PEF 40-69% predicted, can speak in sentences, respiratory rate <25/min, pulse <110/min 2
• Severe exacerbation: PEF <40% predicted, difficulty completing sentences, respiratory rate ≥25/min, pulse ≥110/min, accessory muscle use 1, 2, 4
• Life-threatening features: PEF <33% predicted, silent chest, cyanosis, altered consciousness, exhaustion 4

Primary Standing Doses

Short-Acting Beta-Agonist (First-Line Bronchodilator)

Nebulized albuterol 2.5-5 mg every 20 minutes for 3 doses, then every 1-4 hours as needed based on response 1. This represents the most effective means of reversing airflow obstruction 1. For severe exacerbations (PEF <40%), continuous nebulization may be more effective than intermittent dosing 1.

Alternative delivery: If nebulizer unavailable or patient has mild-to-moderate exacerbation, use albuterol MDI 4-8 puffs every 20 minutes for 3 doses via spacer device, which is equally effective when administered with proper technique 1, 4.

Systemic Corticosteroids (Essential Anti-Inflammatory)

Oral prednisone 40-60 mg once daily (or divided into 2 doses) for 5-10 days without tapering 1, 2. Administer immediately—do not wait to assess bronchodilator response, as anti-inflammatory effects require 6-12 hours to become clinically apparent 1, 3. Early administration reduces hospitalization rates 1.

Critical point: Oral administration is strongly preferred and equally effective as IV therapy when GI absorption is intact 1, 2. Reserve IV hydrocortisone 200 mg (then 200 mg every 6 hours) only for patients actively vomiting, severely ill, or unable to tolerate oral intake 2.

Duration: Continue until PEF reaches ≥70% of predicted or personal best, typically 5-10 days 1, 2. No tapering required for courses <7-10 days, especially if patient is on inhaled corticosteroids 2.

Oxygen Therapy

Supplemental oxygen via nasal cannula or mask to maintain SpO₂ >90% (>95% in pregnant women or patients with heart disease) 1. Monitor continuously until clear response to bronchodilator therapy occurs 1.

Additional Standing Doses for Severe Exacerbations

Ipratropium Bromide (Anticholinergic)

For severe exacerbations (PEF <40%), add ipratropium 0.5 mg to nebulized albuterol every 20 minutes for 3 doses 1. This combination reduces hospitalizations, particularly in patients with severe airflow obstruction 1. After initial 3 doses, continue ipratropium 0.5 mg every 6 hours as needed 1.

Alternative: Ipratropium MDI 8 puffs every 20 minutes for up to 3 hours via spacer 1.

Important limitation: Once hospitalized, adding ipratropium provides no further benefit beyond initial ED treatment 1.

Treatment Algorithm by Severity

Moderate Exacerbation (PEF 40-69%)

1. Albuterol 2.5-5 mg nebulized every 20 minutes × 3 doses 1
2. Prednisone 40-60 mg PO immediately 2
3. Oxygen to maintain SpO₂ >90% 1
4. Reassess after 60-90 minutes 2

Severe Exacerbation (PEF <40%)

1. Albuterol 5 mg nebulized every 20 minutes × 3 doses (consider continuous) 1
2. Add ipratropium 0.5 mg to each albuterol dose × 3 1
3. Prednisone 40-80 mg PO (or IV hydrocortisone 200 mg if unable to take PO) 1, 2
4. High-flow oxygen 40-60% to maintain SpO₂ >90% 1
5. Measure PEF 15-30 minutes after starting treatment 2

Monitoring Parameters

• Peak expiratory flow: Measure 15-30 minutes after initial treatment, then every 4 hours 2, 4
• Vital signs: Continuous pulse oximetry, heart rate, respiratory rate 4
• Clinical response: Ability to speak, accessory muscle use, breath sounds 4

Critical Pitfalls to Avoid

Never delay systemic corticosteroids while giving repeated bronchodilator doses alone—this is a documented cause of preventable asthma deaths 2. Underuse of corticosteroids is a leading preventable factor in asthma mortality 2.

Do not underdose corticosteroids: The 40-60 mg prednisone range is evidence-based; lower doses are inadequate 2. However, doses >60-80 mg provide no additional benefit and increase adverse effects 2.

Do not rely on clinical impression alone: Objective PEF measurement is essential, as subjective assessment often underestimates severity 3.

Do not use sedatives: Contraindicated in acute asthma and may be fatal 2.

Do not taper short steroid courses: For 5-10 day courses, tapering is unnecessary and may lead to underdosing during recovery 2.

Disposition Criteria

Discharge home if: After 1-3 hours of treatment, PEF >70% predicted, symptoms improved, patient can tolerate 4-hour intervals between albuterol doses 1.

Admit to hospital if: Life-threatening features present, PEF remains <40% after treatment, previous severe attacks with rapid onset, or inadequate response after 4 hours 4.