What is the treatment for refractory asthma in the Emergency Room (ER)?

Refractory Asthma Treatment in the Emergency Room

For refractory asthma in the ER that fails to respond to initial bronchodilator therapy, escalate immediately to continuous nebulized albuterol, add ipratropium bromide, administer intravenous magnesium sulfate 2g over 20 minutes, and ensure systemic corticosteroids have been given early—these interventions reduce mortality and prevent respiratory failure. 1

Initial Assessment and Recognition of Refractory Disease

When a patient with acute asthma remains ill despite intensive initial treatment, you must objectively measure severity rather than relying on clinical impression alone, as failure to recognize severe attacks consistently contributes to asthma deaths 2:

• Measure FEV1 or peak expiratory flow (PEF) immediately—refractory cases typically show PEF <40% predicted after initial treatment 1
• Recognize life-threatening features: silent chest, cyanosis, altered mental status, inability to speak, PaCO2 ≥42 mmHg, bradycardia, or exhaustion 1
• Obtain chest radiograph to exclude pneumothorax, consolidation, or pulmonary edema in patients not responding to initial therapy 2

A critical pitfall is underestimating severity—patients, families, and clinicians frequently fail to recognize dangerous exacerbations due to inadequate objective measurements 1.

Escalation of Bronchodilator Therapy

Switch to continuous nebulization rather than continuing intermittent dosing, as this provides superior bronchodilation in severe cases:

• Continuous albuterol nebulization at 0.2 mg/ml (delivering approximately 5 mg/hour) produces significantly greater FEV1 improvement (1.02-1.07 L) compared to standard intermittent dosing (0.72 L improvement) 3
• Standard-dose continuous treatment (2.5-5 mg/hour) has the greatest FEV1 improvement with the fewest side effects compared to high-dose intermittent therapy 3
• If continuous nebulization is unavailable, increase frequency to every 15 minutes for severe exacerbations 1

Add Ipratropium Bromide Immediately

Ipratropium bromide 0.5 mg via nebulizer should be added to albuterol for all refractory cases, given every 20 minutes for 3 doses, then as needed 1:

• The combination of beta-agonist and ipratropium reduces hospitalizations, particularly in patients with severe airflow obstruction 1
• Ipratropium can be mixed in the nebulizer with albuterol if used within one hour 4

Intravenous Magnesium Sulfate for Severe Refractory Cases

Administer magnesium sulfate 2g IV over 20 minutes for patients with severe exacerbations not responding to initial therapy or those with life-threatening features 1:

• Magnesium significantly increases lung function and decreases hospitalization necessity in severe exacerbations with FEV1 or PEF <40% predicted after initial treatment 1
• Pediatric dosing: 25-75 mg/kg (maximum 2g) IV over 20 minutes 1

Ensure Systemic Corticosteroids Were Given Early

A common and dangerous pitfall is delaying corticosteroid administration—they must be given immediately, not after "trying bronchodilators first" 1:

• Prednisolone 30-60 mg orally or hydrocortisone 200 mg IV should have been administered at presentation 1
• Corticosteroids are the only effective treatment for the inflammatory component of asthma, though anti-inflammatory effects may not be apparent for 6-12 hours 5
• If not yet given, administer immediately—oral administration is as effective as intravenous and less invasive 1

Parenteral Bronchodilator Therapy

For patients remaining severely ill despite the above interventions, consider parenteral beta-agonists 2:

• Salbutamol: Loading dose 4 mcg/kg IV/IM/SC, then infusion of 3-20 mcg/min titrated to response 2
• Aminophylline: Loading dose 5 mg/kg by slow IV injection (reduce if patient has taken theophylline within 24 hours), then maintenance infusion 0.6 mg/kg/hour in healthy young adults or 0.4 mg/kg/hour if >65 years or with liver/cardiac disease 2

Critical caveat: Do not give bolus aminophylline to patients already taking oral theophyllines 1. However, note that methylxanthines have increased side effect profiles without superior efficacy and should generally be avoided 1.

Monitoring for Impending Respiratory Failure

Reassess every 15-30 minutes after interventions, looking specifically for 1:

• Drowsiness, confusion, or altered mental status
• Inability to speak or worsening fatigue
• Silent chest on auscultation
• PaCO2 ≥42 mmHg (normal or elevated CO2 in a breathless asthmatic is ominous)
• Intercostal retractions with feeble respiratory effort

Do not delay intubation once it is deemed necessary—it should be performed semi-electively before respiratory arrest occurs 1.

Critical Medications to Avoid

• Never administer sedatives of any kind to patients with acute asthma 1
• Avoid aggressive hydration in older children and adults (may be appropriate for infants and young children) 1
• Do not routinely prescribe antibiotics unless strong evidence of bacterial infection (pneumonia, purulent sputum, sinusitis) exists 2, 1
• Avoid methylxanthines, chest physiotherapy, and mucolytics 1

Hospital Admission Criteria

Admit to hospital ward for patients with 1:

• PEF <50% predicted after 1-2 hours of intensive treatment
• Incomplete response (PEF 40-69% predicted with persistent symptoms)
• Life-threatening features that persist after initial treatment

Consider ICU admission for patients with 1:

• PEF <33% predicted
• Silent chest
• Altered mental status
• Minimal relief from frequent short-acting beta-agonists
• Any signs of impending respiratory failure

Lower your threshold for admission in patients presenting in the afternoon/evening, those with recent nocturnal symptoms, previous severe attacks, or poor social circumstances 1.