Dopamine Infusion Rate Calculation for 1kg Infant at 20 mcg/kg/min
For a 1kg infant receiving dopamine at 20 mcg/kg/min, the infusion rate is 20 mL/hr using the "Rule of 6" preparation method. 1
Calculation Method
Using the "Rule of 6" preparation standard recommended by the American Academy of Allergy, Asthma, and Immunology 2:
- Preparation: 6 × body weight (kg) = mg of dopamine diluted to 100 mL saline 2, 1
- For this 1kg infant: 6 mg dopamine in 100 mL = 60 mcg/mL concentration 1
- Infusion rate formula: 1 mL/hour = 1 mcg/kg/min 2, 1
- Therefore: 20 mL/hour delivers 20 mcg/kg/min 1
Critical Safety Considerations at This Dose
This infant is at the maximum recommended dose and requires immediate clinical reassessment 1:
- The American Academy of Pediatrics recommends dopamine infusion rates of 2-20 mcg/kg/min for cardiogenic/distributive shock 1
- At 20 mcg/kg/min, alpha-adrenergic effects predominate, causing significant vasoconstriction 1
- Risk of serious adverse effects increases substantially at doses >10 mcg/kg/min 1:
Essential Monitoring and Precautions
- Have phentolamine immediately available (0.1-0.2 mg/kg up to 10 mg diluted in 10 mL saline) for intradermal injection if extravasation occurs 2, 1
- Use only an infusion pump, preferably a volumetric pump 3
- Monitor for diminished urine output, increasing tachycardia, or new dysrhythmias as reasons to decrease or temporarily suspend the dosage 3
- Infants with hepatic or renal dysfunction have more than three-fold prolongation of dopamine clearance and are more likely to suffer toxic effects at usual infusion rates 4
Alternative Preparation Methods
If using different concentrations, the FDA-approved calculation is 3:
- Infusion rate (mL/h) = (Weight [kg] × Dose [mcg/kg/min] × 60 min/h) / Concentration (mcg/mL)
- For this patient: (1 kg × 20 mcg/kg/min × 60) / 60 mcg/mL = 20 mL/hr