IV Epinephrine Dosing for Life-Threatening Asthma
For life-threatening asthma with severe respiratory distress, hypoxia, or hypercapnia, administer IV epinephrine as a bolus of 20-200 mcg (0.02-0.2 mg) followed by continuous infusion at 1-10 mcg/min, titrated to clinical response. 1
Initial Bolus Dosing
- Start with 20 mcg IV bolus for patients with life-threatening features who have not responded to nebulized beta-agonists and IV corticosteroids 1
- Escalate to 50-200 mcg bolus if inadequate response after 2 minutes 1, 2
- Prepare by diluting 1 mg (1 mL) of 1:1000 epinephrine in 10 mL normal saline, then administer 0.2-2 mL (20-200 mcg) over several minutes 3
Continuous Infusion Protocol
Standard preparation method: Add 1 mg (1 mL) of 1:1000 epinephrine to 250 mL D5W to yield 4 mcg/mL concentration 3
- Initial infusion rate: 1-4 mcg/min (15-60 drops/min with microdrop apparatus) 3
- Titrate upward to maximum 10 mcg/min based on clinical response and side effects 3
- Alternative concentration: 1 mg in 100 mL saline (1:100,000 solution) infused at 30-100 mL/h (5-15 mcg/min) if infusion pump available 3
Clinical Context for IV Epinephrine Use
Reserve IV epinephrine for patients who:
- Have failed multiple doses of nebulized beta-agonists (salbutamol 5 mg continuously) 3
- Have received IV hydrocortisone 200 mg and show no improvement 3
- Demonstrate life-threatening features: PaCO2 >45 mmHg, severe hypoxia (PaO2 <60 mmHg), silent chest, or altered mental status 3
Critical Safety Considerations
Continuous monitoring is mandatory when administering IV epinephrine 3, 2:
- Every-minute blood pressure and pulse measurements 3
- Continuous ECG monitoring if available 3
- Pulse oximetry and arterial blood gases 3
Adverse events occur in approximately 30% of cases but are mostly minor (tachycardia, tremor); major adverse events (arrhythmias, chest pain, hypotension) occur in only 3.6% 4. In younger adults with life-threatening asthma, IV epinephrine has been shown to be safe with no deaths, cardiac ischemia, or significant arrhythmias in case series 2.
Pediatric Dosing
- Bolus dose: 0.01 mg/kg (0.1 mL/kg of 1:10,000 solution; maximum 0.3 mg) 3
- Infusion by "rule of 6": 0.6 × body weight (kg) = mg diluted to 100 mL saline; then 1 mL/h delivers 0.1 mcg/kg/min 3
When NOT to Use IV Epinephrine
Do NOT give bolus IV epinephrine to patients already taking oral theophyllines without first checking levels, as this increases risk of toxicity 3. Instead, use IV aminophylline 250 mg over 20 minutes OR IV salbutamol/terbutaline 250 mcg over 10 minutes as alternatives 3.
Concurrent Essential Therapies
While preparing epinephrine infusion, ensure: