Dose Conversion Calculation
To convert 0.25 mcg/kg/min to mcg/min, you must multiply by the patient's weight in kilograms: 0.25 mcg/kg/min × patient weight (kg) = total mcg/min.
Mathematical Formula
The conversion follows this straightforward calculation 1:
- Infusion rate (mcg/min) = dose (mcg/kg/min) × weight (kg)
For example:
- In a 70-kg adult: 0.25 mcg/kg/min × 70 kg = 17.5 mcg/min 1
- In a 1-kg infant: 0.25 mcg/kg/min × 1 kg = 0.25 mcg/min 2
- In a 10-kg child: 0.25 mcg/kg/min × 10 kg = 2.5 mcg/min 1
Clinical Context for Common Medications
This dose range (0.25 mcg/kg/min) is clinically relevant for several vasoactive medications:
Milrinone
- 0.25-0.75 mcg/kg/min is the standard maintenance infusion range after a loading dose 1
- This represents an inodilator used for cardiac output support in post-resuscitation care 1
Epinephrine
- 0.1-0.5 mcg/kg/min is used for post-cardiac arrest hemodynamic support 1
- In a 70-kg adult, this translates to 7-35 mcg/min 1
- Low-dose epinephrine (<0.3 mcg/kg/min) produces predominantly β-adrenergic effects 1
Practical Infusion Calculation
The American Heart Association provides an alternative formula for verifying continuous infusion rates 1:
Infusion rate (mL/h) = [weight (kg) × dose (mcg/kg/min) × 60 (min/hour)] ÷ concentration (mcg/mL)
This allows you to calculate the pump rate once you know the drug concentration in your prepared solution 1.
Critical Pitfall to Avoid
Never attempt to convert mcg/kg/min to mcg/min without knowing the patient's actual body weight 1. Weight-based dosing exists precisely because the absolute dose varies dramatically between patients—a dose appropriate for an infant would be subtherapeutic in an adult, while an adult dose would be toxic in a child 1, 2.