Zoe", a 40 kg labrador retriever is recovering after a liver mass resection. the doctor asks you to start "zoe" on a fentanyl constant rate infusion at 4 micrograms per kilogram per hour (ug/kg/hr). the concentration of fentanyl is 0.05mg/ml. the fluid rate is currently set at 100 ml/hour. how much fentanyl will you add to a liter of normosol-r?
1-convert pounds to kilograms- note that in this problem the units are already in kg so no conversion is necessary. make sure to pay attention to this.
2-calculate the number of hours an infusion will last by dividing the volume in the bag (1 liter, or 1,000 ml) by the rate per hour: 1,000 ml/100ml/hr = 10 hours
3-(if the problem asks for a dose per minute, you will need to multiply the hours by 60 to convert to minutes, but since this problem asks for ug/kg/hour, you do not need to further convert)
4-now plug into the equation: 4 ug/40kg/10 hours= 1600 ug
5-now convert the ug into mg by dividing by 1,000: 1600/1,000 = 1.6 mg
6-calculate the quantity of fentanyl to add by now dividing the 1.6 mg by the concentration of the drug (0.05 mg/ml) : 1.6mg/0.05mg/ml = 32 ml