What is the appropriate initial assessment and management for a patient presenting with an acute asthma exacerbation?

Acute Asthma Exacerbation: Initial Assessment and Management

Immediate Treatment (First 15–30 Minutes)

Administer three therapies simultaneously without delay: high-dose inhaled β₂-agonist, systemic corticosteroids, and supplemental oxygen. 1, 2, 3

Bronchodilator Therapy

• Give albuterol 2.5–5 mg via oxygen-driven nebulizer OR 4–8 puffs via metered-dose inhaler with spacer every 20 minutes for three consecutive doses 1, 2, 3
• For children weighing <15 kg, use half the adult dose (2.5 mg albuterol) 1, 2, 3
• Add ipratropium bromide 0.5 mg to each nebulizer treatment (or 8 puffs via MDI) for all moderate-to-severe exacerbations—this combination reduces hospitalization risk 1, 2, 3

Systemic Corticosteroids (Must Be Given Immediately)

• Adults: prednisolone 40–60 mg orally OR IV hydrocortisone 200 mg 1, 2, 3
• Children: prednisolone 1–2 mg/kg (maximum 40–60 mg) 1, 2, 3
• Oral administration is as effective as intravenous and is strongly preferred when tolerated 1, 2, 3
• Do NOT delay corticosteroids while "trying bronchodilators first"—clinical benefits require 6–12 hours minimum, so immediate administration is critical 1, 2, 4

Oxygen Therapy

• Deliver 40–60% oxygen via face mask or nasal cannula to maintain SaO₂ >90% (target >95% in pregnant patients or those with cardiac disease) 1, 2, 3

Severity Assessment (Within First 5–15 Minutes)

Obtain objective measurements—failure to do so is the most common preventable cause of asthma deaths. 1, 2, 3

Measure Peak Expiratory Flow (PEF) or FEV₁ Before Treatment

• Severe exacerbation: inability to speak full sentences in one breath, respiratory rate >25/min, heart rate >110/min, PEF <50% predicted 1, 2, 3
• Life-threatening features: PEF <33% predicted, silent chest, cyanosis, feeble respiratory effort, altered mental status (confusion/drowsiness), bradycardia or hypotension, normal or elevated PaCO₂ ≥42 mmHg in a breathless patient 1, 2, 3

Identify High-Risk Patients Requiring Heightened Vigilance

• Previous intubation or ICU admission for asthma 1, 3
• ≥2 hospitalizations or ≥3 emergency department visits in past year 1, 3
• Using >2 canisters of short-acting β-agonist per month 1, 3
• Recent hospitalization or ED visit within past month 1, 3
• Difficulty perceiving asthma symptom severity 1, 3

Reassessment After Initial Treatment (15–30 Minutes)

Re-measure PEF/FEV₁ and reassess symptoms, vital signs, and oxygen saturation to guide next steps. 1, 2, 3

Good Response (PEF >75% Predicted)

• Continue usual maintenance therapy with modest step-up 1, 2, 3
• Monitor symptoms and PEF on chart 1, 2
• Arrange follow-up within 48 hours 1, 2

Incomplete Response (PEF 50–75% Predicted)

• Continue nebulized β-agonist every 4–6 hours 1, 2, 3
• Maintain oral corticosteroids 1, 2, 3
• Consider hospital admission if severe features persist 1, 2, 3

Poor Response (PEF <50% Predicted or Persistent Severe Features)

• Increase nebulized β-agonist frequency to every 15–30 minutes 1, 2, 3
• Continue ipratropium bromide 0.5 mg every 20 minutes for additional doses 1, 2, 3
• Arrange immediate hospital admission 1, 2, 3

Escalation for Refractory Cases (After 1 Hour of Intensive Therapy)

Intravenous Magnesium Sulfate

• Give 2 g IV over 20 minutes for severe exacerbations with PEF <40% after initial treatment or life-threatening features 1, 2, 3
• Pediatric dose: 25–75 mg/kg (maximum 2 g) IV over 20 minutes 2, 3

Consider Additional Therapies

• Continuous nebulized albuterol for markedly severe cases 2, 3
• IV aminophylline 250 mg over 20 minutes for life-threatening features 1, 2, 3
• NEVER give bolus aminophylline to patients already on oral theophylline—risk of toxicity without added benefit 1, 2, 3

Hospital Admission Criteria

Admit immediately for any of the following: 1, 2, 3

• Any life-threatening feature present (PEF <33%, silent chest, altered mental status, PaCO₂ ≥42 mmHg)
• Features of severe attack persisting after initial treatment
• PEF <50% predicted after 1–2 hours of intensive treatment

Lower threshold for admission when: 1, 2, 3

• Presentation in afternoon/evening
• Recent nocturnal symptoms or worsening pattern
• Previous severe attacks requiring intubation
• Poor social circumstances limiting reliable monitoring

ICU Transfer Criteria

Transfer to intensive care with a physician prepared to intubate when: 1, 2, 3

• Deteriorating PEF despite ongoing therapy
• Worsening or persistent hypoxia/hypercapnia
• Exhaustion, feeble respirations, or altered mental status
• Coma or respiratory arrest

Critical Pitfalls to Avoid

• NEVER administer sedatives of any kind—absolutely contraindicated and potentially fatal 1, 2, 3
• Do NOT rely solely on subjective assessment—objective PEF/FEV₁ measurement is mandatory 1, 2, 3
• Do NOT delay corticosteroids while attempting bronchodilator therapy alone 1, 2, 3
• Do NOT underestimate severity—patients, families, and clinicians frequently fail to recognize dangerous exacerbations 1, 2, 3
• Avoid routine antibiotics unless strong evidence of bacterial infection (pneumonia, sinusitis) 2, 3
• Avoid methylxanthines (theophylline) due to increased side effects without superior efficacy 2, 3

Discharge Planning (After Stabilization)

Patients may be discharged when: 1, 2, 3

• PEF ≥70–75% of predicted or personal best
• Symptoms minimal or absent
• Oxygen saturation stable on room air
• Patient stable for 30–60 minutes after last bronchodilator dose
• Patient has been on discharge medications for 24 hours

Before discharge, ensure: 1, 2, 3

• Continue oral corticosteroids for 5–10 days (no taper needed for courses <10 days)
• Initiate or continue inhaled corticosteroids
• Verify and document correct inhaler technique
• Provide written asthma action plan with PEF zones
• Supply peak flow meter if patient does not have one
• Arrange primary care follow-up within 1 week
• Arrange specialist follow-up within 4 weeks