A patient is receiving an IV of esmolol 2.5 grams in 250 mL D5W (dextrose 5% in water) infusing at 200 micrograms/kilogram/minute. The patient weighs 110 lb. What rate (in mL/hr) should the nurse program into the IV pump to deliver this dose?
A.
45 mL/hr
B.
60 mL/hr
C.
75 mL/hr
D.
90 mL/hr
The Correct Answer and Explanation is:
To determine the correct IV infusion rate for the esmolol infusion, we need to follow these steps:
- Convert the patient’s weight from pounds to kilograms:The patient weighs 110 pounds. To convert this to kilograms:Weight (kg)=Weight (lb)×1 kg2.2 lb\text{Weight (kg)} = \text{Weight (lb)} \times \frac{1 \text{ kg}}{2.2 \text{ lb}}Weight (kg)=Weight (lb)×2.2 lb1 kg Weight (kg)=110 lb×1 kg2.2 lb=50 kg\text{Weight (kg)} = 110 \text{ lb} \times \frac{1 \text{ kg}}{2.2 \text{ lb}} = 50 \text{ kg}Weight (kg)=110 lb×2.2 lb1 kg=50 kg
- Calculate the total dose required per minute:The esmolol infusion rate is 200 micrograms per kilogram per minute.Dose (micrograms/min)=Weight (kg)×Rate (micrograms/kg/min)\text{Dose (micrograms/min)} = \text{Weight (kg)} \times \text{Rate (micrograms/kg/min)}Dose (micrograms/min)=Weight (kg)×Rate (micrograms/kg/min) Dose (micrograms/min)=50 kg×200 micrograms/kg/min=10,000 micrograms/min\text{Dose (micrograms/min)} = 50 \text{ kg} \times 200 \text{ micrograms/kg/min} = 10,000 \text{ micrograms/min}Dose (micrograms/min)=50 kg×200 micrograms/kg/min=10,000 micrograms/min
- Convert micrograms to milligrams:Since 1 milligram = 1,000 micrograms:Dose (mg/min)=10,000 micrograms/min1,000 micrograms/mg=10 mg/min\text{Dose (mg/min)} = \frac{10,000 \text{ micrograms/min}}{1,000 \text{ micrograms/mg}} = 10 \text{ mg/min}Dose (mg/min)=1,000 micrograms/mg10,000 micrograms/min=10 mg/min
- Calculate the total volume needed per minute:We have a solution of esmolol at 2.5 grams (or 2,500 mg) in 250 mL D5W.Concentration (mg/mL)=2,500 mg250 mL=10 mg/mL\text{Concentration (mg/mL)} = \frac{2,500 \text{ mg}}{250 \text{ mL}} = 10 \text{ mg/mL}Concentration (mg/mL)=250 mL2,500 mg=10 mg/mLTo find the volume needed to deliver 10 mg per minute:Volume (mL/min)=Dose (mg/min)Concentration (mg/mL)\text{Volume (mL/min)} = \frac{\text{Dose (mg/min)}}{\text{Concentration (mg/mL)}}Volume (mL/min)=Concentration (mg/mL)Dose (mg/min) Volume (mL/min)=10 mg/min10 mg/mL=1 mL/min\text{Volume (mL/min)} = \frac{10 \text{ mg/min}}{10 \text{ mg/mL}} = 1 \text{ mL/min}Volume (mL/min)=10 mg/mL10 mg/min=1 mL/min
- Convert the rate to mL per hour:To convert mL per minute to mL per hour:Rate (mL/hr)=Rate (mL/min)×60 min/hr\text{Rate (mL/hr)} = \text{Rate (mL/min)} \times 60 \text{ min/hr}Rate (mL/hr)=Rate (mL/min)×60 min/hr Rate (mL/hr)=1 mL/min×60=60 mL/hr\text{Rate (mL/hr)} = 1 \text{ mL/min} \times 60 = 60 \text{ mL/hr}Rate (mL/hr)=1 mL/min×60=60 mL/hr
Therefore, the nurse should program the IV pump to deliver the esmolol infusion at a rate of 60 mL/hr.
So, the correct answer is B. 60 mL/hr.