Download Need/Have (N/H)

Need/Have (N/H)
Set-up:
N X V = dose
H
(N) What you need to give the patient
(H) What you have to give
X (V)vehicle (method of delivery, example – tablets, mL)
When you are figuring a problem, the KNOWN part of your dose (such as: Tylenol, 500 mg/per tablet) is the
HAVE and the VEHICLE – the “500 mg” is the HAVE and the “(1) tablet” is the VEHICLE (method of
delivery).
** Hint: The labels of the NEED and the HAVE must be the same label. If you have set up your problem and the labels of NEED
and HAVE are not the same label, your set-up is incorrect.
If the order is for 1000 mg of Tylenol every four hours, and your available dosage is 500 mg/tab, the set up is:
(N) 1000 mg
(H) 500 mg
X (V) 1 tab = 2 tabs (answer is always labeled with the vehicle label)
** 1000 divided by 500 = 2
2 X 1 (tab) = 2 tabs
Example:
1) Your patient is receiving Demerol for pain. The physician has ordered 50 mg of Demerol IM every 4 to
6 hours PRN. You get a vial of Demerol from the narcotic drawer which reads on the label 100 mg/mL.
What will you give your patient?
You NEED (N) 50 mg
You HAVE (H) 100 mg in
(V) 1 mL.
(N) 50 mg X (V) 1 mL = 0.5 mL
(H) 100 mg
Labels are equally as important as the math. Be sure you know what your label should be and USE IT! In
the above equation, if you had inadvertently used “mg” as your label, your math would have been correct at the
0.5, but your label would be wrong and you would have reduced the ordered amount of medication from “50
mg” to “0.5 mg.” OOPS! (100 times LESS than the doctor ordered.) Or worse, if you somehow would have
gotten your “50” mg in your answer, and you labeled it “50 mL.” BIGGER OOPS! (100 times MORE than the
doctor ordered.) And really dangerous/deadly to your patient! KNOW YOUR LABEL!!
** When using numbers less than “1” always place a “0” before the decimal (example: 0.5, 0.75, 0.01).
This will indicate there is a decimal there, even if somewhere in the transfer of med orders the decimal would
be overlooked from one nurse to the other. (You would not lead a whole number with a zero, so the zero would
be a cue to the next RN/LPN.)
Practice problems:
1)
A patient is to receive Valium 10 mg TID. The available tablets are labeled 5 mg.
How many tabs will you give?
2)
The physician orders Lasix 40 mg. The drug label reads Lasix 20 mg/ml.
What will you give?
3)
The physician orders 5 mg of a drug to be given. You have 2.5 mg tabs available.
How many tabs should you give?
4)
You have 15 mg/ml of Morphine Sulfate. The order is for 10 mg to be given.
How much should be administered?
5)
The physician orders Gentamycin 60 mg IM. The drug label reads Gentamycin 40 mg/mL.
How much will you give?
6)
The order is for Librium 25 mg IM. The drug label reads Librium 100 mg/2ml.
How much will you give?
7)
The physician orders Digoxin 0.5 mg. The drug label reads Digoxin 0.25 mg per tab.
What will you give?
8)
The order is for Pen-Vee K 250 mg. The drug label reads Pen-Vee K 125mg/ml.
How much will you give?
Solutions to Practice problems:
1)
A patient is to receive Valium 10 mg TID. The available tablets are labeled 5 mg.
How many tabs will you give?
(N) 10 mg X (V) 1 tablet = 2 tablets
(H) 5 mg
2)
The physician orders Lasix 40 mg. The drug label reads Lasix 20 mg/ml.
What will you give?
(N) 40 mg X (V) 1 mL = 2 mL
(H) 20 mg
3)
The physician orders 5 mg of a drug to be given. You have 2.5 mg tabs available.
How many tabs should you give?
(N) 5 mg X (V) 1 tablet = 2 tablets
(H) 2.5 mg
4)
You have 15 mg/ml of Morphine Sulfate. The order is for 10 mg to be given.
How much should be administered?
(N) 10 mg X (V) 1 mL = 0.66666 . . . = 0.67 mL or = 0.7 mL
(H) 15 mg
5)
The physician orders Gentamycin 60 mg IM. The drug label reads Gentamycin 40 mg/mL.
How much will you give?
1.5 mL
6)
The order is for Librium 25 mg IM. The drug label reads Librium 100 mg/2ml.
How much will you give?
0.5 mL
7)
The physician orders Digoxin 0.5 mg. The drug label reads Digoxin 0.25 mg per tab.
What will you give?
2 tabs
8)
The order is for Pen-Vee K 250 mg. The drug label reads Pen-Vee K 125mg/ml.
How much will you give?
2 mL