How do you convert micrograms (mcg) per kilogram (kg) per minute to milligrams (mg) per kilogram (kg) per minute for a dose administered in normal saline?

Converting Micrograms per Kilogram per Minute to Milligrams per Kilogram per Minute

To convert micrograms (mcg) per kg per minute to milligrams (mg) per kg per minute, divide the microgram value by 1000, as 1 mg equals 1000 mcg.

Conversion Process

• 1 milligram (mg) = 1000 micrograms (mcg) 1
• Therefore, to convert from mcg/kg/min to mg/kg/min, divide the mcg value by 1000 1

Example Calculation

• If a medication dose is 10 mcg/kg/min:
  • 10 mcg/kg/min ÷ 1000 = 0.01 mg/kg/min 1

Preparing Infusions in Normal Saline 500 mL

When preparing an infusion in 500 mL of normal saline:

1. Calculate the total amount of medication needed:

   • Total mg = (dose in mg/kg/min) × (patient weight in kg) × (infusion duration in minutes) 1

2. Add this calculated amount to the 500 mL normal saline bag 1

3. Set the infusion rate according to the prescribed dose 1

Practical Application for Common Medications

• For epinephrine infusions:

  • Standard dose range: 0.1-1.0 mcg/kg/min (which equals 0.0001-0.001 mg/kg/min) 1
  • For shock management, doses up to 5 mcg/kg/min (0.005 mg/kg/min) may be necessary 1

• For dopamine infusions:

  • Standard dose range: 2-20 mcg/kg/min (which equals 0.002-0.02 mg/kg/min) 1

Common Pitfalls to Avoid

• Confusing concentration expressions (e.g., 1:1000 vs. 1:10,000 solutions) can lead to serious dosing errors 2
• Always double-check your calculations, especially for high-alert medications like epinephrine 1
• Be aware that medical students and healthcare professionals frequently make errors when calculating drug concentrations in solution 2

Remember that accurate dose calculations are critical for patient safety, as medication dosing errors can cause significant harm, particularly in pediatric populations 3.