What is the management of asthma exacerbation?

Management of Asthma Exacerbation

Administer oxygen to maintain SaO₂ >90% (>95% in pregnancy/heart disease), immediately give albuterol 2.5-5 mg via nebulizer every 20 minutes for 3 doses, add ipratropium bromide 0.5 mg for moderate-to-severe cases, and start systemic corticosteroids (prednisone 40-60 mg orally or IV methylprednisolone 125 mg) within the first 15-30 minutes. 1, 2, 3

Initial Assessment and Severity Classification

Assess severity immediately using symptoms, vital signs, and peak expiratory flow (PEF) or FEV₁:

• Mild exacerbation: Dyspnea only with activity, PEF ≥70% of predicted/personal best 1, 3
• Moderate exacerbation: Dyspnea interfering with usual activity, PEF 40-69% of predicted, respiratory rate >25 breaths/min, heart rate >110 beats/min 1, 3
• Severe exacerbation: Dyspnea at rest, PEF <40% of predicted, inability to complete sentences in one breath 1, 3
• Life-threatening features: PEF <33% predicted, silent chest, cyanosis, confusion, drowsiness, altered mental status, PaCO₂ ≥42 mmHg 1, 3

Primary Treatment Algorithm (First 15-30 Minutes)

Oxygen Therapy

• Administer oxygen via nasal cannula or mask to maintain SaO₂ >90% (>95% in pregnant patients or those with heart disease) 1, 2, 3
• Monitor oxygen saturation continuously until clear response to bronchodilator therapy 1, 2, 3

Bronchodilator Therapy

Albuterol (first-line treatment for all exacerbations):

• Nebulizer: 2.5-5 mg every 20 minutes for 3 doses, then 2.5-10 mg every 1-4 hours as needed 1, 2, 3, 4
• MDI with spacer: 4-8 puffs every 20 minutes for up to 3 doses (equally effective as nebulizer when properly administered) 3, 5
• For severe exacerbations (PEF <40%): Consider continuous nebulization rather than intermittent dosing 1, 2, 3

Ipratropium bromide (add to albuterol for moderate-to-severe exacerbations):

• 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 2, 3

Systemic Corticosteroids (Essential for Moderate-to-Severe Cases)

Administer within the first 15-30 minutes:

• Adults: Prednisone 40-60 mg orally in single or divided doses 1, 2, 3
• Children: Prednisone 1-2 mg/kg/day (maximum 60 mg/day) 3
• Alternative for adults: Dexamethasone 16 mg orally daily for 2 days 1
• For severe cases unable to tolerate oral: IV methylprednisolone 125 mg or IV dexamethasone 10 mg 1
• Duration: 5-10 days for outpatient therapy; no tapering needed for courses <10 days 2, 3

Reassessment at 15-30 Minutes

Measure PEF or FEV₁, assess symptoms, vital signs, and oxygen saturation: 1, 3

• Good response (PEF ≥70% predicted, minimal symptoms): Continue albuterol every 4-6 hours, oral corticosteroids, and consider discharge planning 3
• Incomplete response (PEF 40-69% predicted): Continue frequent albuterol, ensure systemic corticosteroids given, consider adjunctive therapies 1, 3
• Poor response (PEF <40% predicted): Escalate to severe exacerbation management, consider hospital admission 1, 3

Management of Severe/Refractory Exacerbations

Adjunctive Therapies

Intravenous magnesium sulfate (for severe refractory asthma):

• Adults: 2 g IV over 20 minutes 1, 2, 3
• Children: 25-75 mg/kg (maximum 2 g) IV over 20 minutes 3
• Consider early in severe cases or after 1 hour of intensive treatment without adequate response 1, 3

Continuous albuterol nebulization:

• For severe exacerbations not responding to intermittent dosing 1, 2, 3

Heliox (helium-oxygen mixture):

• May be considered for severe refractory cases before intubation 3

Therapies to AVOID

• Theophylline/methylxanthines: Increased side effects without superior efficacy 3, 6
• Sedatives: Never administer to patients with acute asthma 3
• Antibiotics: Not recommended unless strong evidence of bacterial infection (pneumonia, sinusitis) 3
• Aggressive hydration: Not recommended for older children and adults 3
• Chest physiotherapy and mucolytics: Should be avoided 3

Recognition of Impending Respiratory Failure

Monitor for these warning signs:

• Inability to speak, altered mental status 3
• Intercostal retractions, worsening fatigue 3
• PaCO₂ ≥42 mmHg (normal or elevated CO₂ in a breathless asthmatic is life-threatening) 3
• Silent chest, cyanosis, feeble respiratory effort 3

Do not delay intubation once deemed necessary; perform semi-electively before respiratory arrest occurs 3

Hospital Admission Criteria

Admit to hospital if:

• Any life-threatening features present (PEF <33%, silent chest, cyanosis, confusion, PaCO₂ ≥42 mmHg) 1, 3
• PEF <50% predicted after 1-2 hours of intensive treatment 3
• Features of severe attack persist after initial treatment 1, 3
• Lower threshold for admission if: Afternoon/evening presentation, recent nocturnal symptoms, previous severe attacks, history of intubation, poor social circumstances 3, 7

Discharge Criteria and Planning

Patients may be discharged when:

• PEF ≥70% of predicted or personal best 3
• Symptoms minimal or absent 3
• Oxygen saturation stable on room air 3
• Stable for 30-60 minutes after last bronchodilator dose 3

At discharge, ensure:

• Continue oral corticosteroids for 5-10 days (no taper needed) 2, 3
• Initiate or continue inhaled corticosteroids 3
• Provide written asthma action plan 8, 3
• Review and confirm proper inhaler technique 3
• Arrange follow-up with primary care within 1 week 3
• Consider IM depot corticosteroid for patients at high risk of non-adherence 3

Common Pitfalls to Avoid

• Underestimating severity: Patients, relatives, and physicians often underestimate exacerbation severity due to failure to make objective measurements (PEF/FEV₁) 3
• Delaying corticosteroids: Early administration (within first hour) significantly reduces hospitalization rates 1, 3
• Inadequate initial bronchodilator dosing: Receiving <3 doses of nebulized salbutamol in the emergency room is associated with treatment failure 7
• Using albuterol alone for moderate-to-severe cases: Always add ipratropium bromide 1, 2, 3
• Delaying intubation: Once deemed necessary, perform semi-electively rather than emergently 3