A nurse is preparing to administer esmolol 50 mcg/kg/min by continuous IV infusion to a client who weighs 110 lb. Available is esmolol 2.5g in dextrose 5% in water 250 mL. The nurse should set the IV pump to deliver how many mL/hr? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
The Correct Answer and Explanation is:
To determine the infusion rate of esmolol in mL/hr, we need to follow these steps:
- Convert the client’s weight from pounds to kilograms:
- 1 pound = 0.453592 kilograms
- Weight in kilograms = 110 lb × 0.453592 kg/lb = 49.895 kg (approximately 50 kg)
- Calculate the total dose of esmolol required per minute:
- Dosage = 50 mcg/kg/min
- Total dose = 50 mcg/kg/min × 50 kg = 2500 mcg/min
- Convert the total dose from micrograms to grams:
- 1 gram = 1,000,000 micrograms
- Total dose in grams = 2500 mcg ÷ 1,000,000 = 0.0025 grams/min
- Determine the concentration of esmolol in the IV solution:
- Available solution: 2.5 grams in 250 mL
- Concentration = 2.5 grams / 250 mL = 0.01 grams/mL
- Concentration in micrograms/mL = 0.01 grams/mL × 1,000,000 mcg/grams = 10,000 mcg/mL
- Calculate the infusion rate in mL/min:
- Required dose = 0.0025 grams/min
- Concentration = 10,000 mcg/mL
- Infusion rate = Required dose / Concentration
- Infusion rate = 0.0025 grams/min / 0.01 grams/mL = 0.25 mL/min
- Convert the infusion rate to mL/hr:
- Infusion rate in mL/hr = 0.25 mL/min × 60 min/hr = 15 mL/hr
Therefore, the nurse should set the IV pump to deliver 15 mL/hr.
Explanation
In this problem, we need to adjust the infusion rate based on the weight of the client and the concentration of the medication. Esmolol is dosed based on the client’s weight and delivered as a continuous infusion. By converting the client’s weight to kilograms, we calculate the required dosage per minute. Next, converting this dosage into grams and comparing it to the concentration of the solution helps determine the volume required per minute. Finally, converting the rate from per minute to per hour gives the infusion rate to be set on the IV pump. This ensures the correct dose of esmolol is administered continuously.