What is the recommended adrenaline (epinephrine) dose and administration route for acute bronchospasm in adults and children?

Adrenaline Dosing for Acute Bronchospasm

For acute bronchospasm, adrenaline is NOT first-line therapy—inhaled beta-2 agonists (albuterol) are the primary treatment—but when adrenaline is indicated for severe, refractory bronchospasm, administer 0.3-0.5 mg (0.3-0.5 mL of 1:1,000 solution) subcutaneously in adults, or 0.01 mg/kg (maximum 0.3-0.5 mg) subcutaneously in children, repeated every 15-20 minutes for up to 3 doses. 1

When to Use Adrenaline for Bronchospasm

Adrenaline should be reserved for severe asthma exacerbations that fail to respond adequately to first-line inhaled beta-agonists, particularly when life-threatening features are present (peak expiratory flow <40% predicted, severe airway obstruction, or inadequate response to initial nebulized therapy). 1 This is a critical distinction: adrenaline is not routine therapy for bronchospasm but rather a rescue intervention for refractory cases.

Adult Dosing Protocol

• Dose: 0.3-0.5 mg (0.3-0.5 mL of 1:1,000 solution) 1
• Route: Subcutaneous injection into the anterolateral aspect of the mid-thigh 1
• Frequency: Repeat every 15-20 minutes as needed, up to 3 doses maximum 2, 1
• Monitoring: Assess peak expiratory flow 15-30 minutes after each dose and monitor for cardiovascular effects (tachycardia, hypertension, myocardial irritability) 1

Pediatric Dosing Protocol

• Dose: 0.01 mg/kg subcutaneously, maximum 0.3-0.5 mg per injection 1
• Route: Subcutaneous injection into the anterolateral thigh 1
• Frequency: Repeat every 15-20 minutes for up to 3 doses as needed 1

Critical Context: First-Line Therapy is NOT Adrenaline

Inhaled beta-2 agonists (albuterol/salbutamol) remain the primary bronchodilator for acute bronchospasm. 2, 3 The standard approach is:

• Adults: Nebulized albuterol 2.5-5 mg in 3 mL saline every 20 minutes for 3 doses, then as needed 2, 3
• Children 5-11 years: 1.25-5 mg nebulized every 20 minutes 3
• Children <5 years: 0.63 mg/3 mL nebulized 3

Adrenaline is considered only when bronchospasm is resistant to adequate doses of inhaled beta-agonists. 2

Essential Concurrent Therapies

When adrenaline is administered for severe bronchospasm, you must simultaneously continue:

• High-dose nebulized beta-2 agonists (albuterol 2.5-5 mg every 20 minutes) 2, 1
• Systemic corticosteroids (methylprednisolone 125 mg IV or prednisone 0.5 mg/kg orally) 2, 1
• Oxygen therapy to maintain SpO2 >90% 1
• Ipratropium bromide 0.25-0.5 mg nebulized (can be mixed with albuterol for first 3 doses) 2, 1

Anaphylaxis-Related Bronchospasm: Different Context

If bronchospasm occurs in the context of anaphylaxis, adrenaline becomes first-line therapy with the same dosing:

• Adults: 0.3-0.5 mg IM (1:1,000) every 5-15 minutes 2
• Children: 0.01 mg/kg IM (maximum 0.3 mg) every 5-15 minutes 2

In anaphylaxis, inhaled beta-agonists are adjunctive therapy for bronchospasm that persists despite adequate adrenaline dosing. 2

Alternative: Terbutaline

Terbutaline 0.25 mg subcutaneously can be used as an alternative to adrenaline, repeated every 20 minutes for up to 3 doses. 1 This provides selective beta-2 agonism with fewer cardiovascular side effects than adrenaline.

Critical Pitfalls to Avoid

• Never use the 1:10,000 concentration (intended for IV cardiac arrest) for subcutaneous bronchospasm treatment—this will result in underdosing 1
• Do not give adrenaline intravenously in conscious patients with bronchospasm due to risk of lethal arrhythmias 2
• Do not delay or withhold nebulized selective beta-2 agonists when giving adrenaline—they work synergistically 1
• Do not administer sedatives during acute bronchospasm as they can worsen respiratory depression 1

Refractory Bronchospasm: Advanced Options

For intubated patients with severe bronchospasm refractory to all standard therapies, case reports support endotracheal administration of 0.5 mg epinephrine (1:10,000) diluted in 10 mL normal saline, which has shown immediate improvement in oxygen saturation and airway pressures. 4, 5 This is a last-resort intervention when standard therapies fail.

Patients on Beta-Blockers

Patients receiving beta-adrenergic blockers may have blunted or paradoxical responses to adrenaline, with potential for unopposed alpha-adrenergic effects causing worsened bronchospasm and cardiovascular instability. 2 In these patients, consider glucagon 1-5 mg IV over 5 minutes (20-30 mcg/kg in children, maximum 1 mg) followed by infusion, as glucagon bypasses beta-receptor blockade. 2 Inhaled beta-2 agonists may still be effective despite systemic beta-blockade. 6

Disposition

Any patient requiring adrenaline for severe bronchospasm should be referred to the hospital immediately, especially if life-threatening features are present, peak expiratory flow remains <33% predicted, or severe features persist after initial treatment. 1