Calculating IV Rate Questions.

1. I really need some help with dosage problems. We are having our lab checkoff on Tues. Here is the question and I can not figure out how to even put the problem on paper. What formula do I use? How do I solve this? I am sure that it is something simple but I am stumped. Here goes. There are five questions in all.

1. Infuse Vibramycin 100 mg IVPB mixed in 50 ml NS over 45 minutes. Calculate the IV rate.

2. The order reads "Atropine gr 1/400 IM on call to OR." The vial reads Atropine 0.6 mg/ml. How much will you give?

3. The physician orders Ampicillin 300 mg IM every 8 hours. The vial reads to add 4 ml of Normal Saline to equal a concentration of 1Gm = 5 ml. How many ml's will the nurse give?

4. Infuse 1000ml 0.45 NS over 6 hours. Calculate the IV pump rate. (I think the answer is 167ml/hr)

5. The medication order reads: Heparin sodium 400 units/hr IV. Supply: Infusion pump, standard solution of Heparin sodium 25,000 units in 250 ml D5W. What is the rate?

6. Order dopamine 2mcg/kg/min.
Supply: Infusion pump, standard solution 200 mg in 250 ml D5W. Client weights 176 lbs. Calculate the IV pump rate.

Thanks in advance for any help.

•

Joined: Oct '08; Posts: 2

3. Basically all one needs to know is:
Amount to Give (vol)=Dose/Conc
You can then extend it to accomodate rate, weight, drip factor etc.
So let's take #6.
First let's convert all to same units, makes life easier.
176 lb=80 kg
200 mg=200,000 mcg
So dose=80x2=160 mcg/min
Conc=200,000 mcg/250 mL=800 mcg/mL
So Amount to Give (in mL/min)=Dose (160 mcg/min) divided by Conc (800 mcg/mL) or 0.2 mL/min or 12 mL/hr
(If say they wanted to make things a little more complicated & wanted gtt, say w/ drip factor=20 gtt/mL), answe would have been 20x12 gtt/hr
4. infuse vibramycin 100 mg ivpb mixed in 50 ml ns over 45 minutes. calculate the iv rate.
50 ml/45 minutes x 60 minutes/1 hour = 66.66 ml/hour, round off to 67 ml/hour (iv rate)

the order reads "atropine gr 1/400 im on call to or." the vial reads atropine 0.6 mg/ml. how much will you give?
1 grain/400 (dose desired) x 1 ml/0.6 mg (dose on hand) x 60 mg/1 grain (conversion factor) = 0.25 ml (amount to give)

the physician orders ampicillin 300 mg im every 8 hours. the vial reads to add 4 ml of normal saline to equal a concentration of 1gm = 5 ml. how many ml's will the nurse give?
300 mg/1 (dose desired) x 5 ml/1 gram (dose on hand) x 1 gram/1000 mg (conversion factor) = 1.5 ml (amount to give)

infuse 1000ml 0.45 ns over 6 hours. calculate the iv pump rate. (i think the answer is 167ml/hr)
you are correct.

the medication order reads: heparin sodium 400 units/hr iv. supply: infusion pump, standard solution of heparin sodium 25,000 units in 250 ml d5w. what is the rate?
400 units/hour (dose desired) x 250 ml/25,000 units (dose on hand) = 4 ml/hour (infusion rate)

order dopamine 2mcg/kg/min.
supply: infusion pump, standard solution 200 mg in 250 ml d5w. client weights 176 lbs. calculate the iv pump rate.
2 mcg/kg (dose desired) x 176 pounds/minute (patient weight/dose desired) x 1 kg/2.2 pound (conversion factor) x 250 ml/ 200 mg (dose on hand) x 1 mg/1000 mcg (conversion factor) x 60 minutes/1 hour (conversion factor) = 12 ml/hour (infusion rate)

close