Med Math Review (Level 1)(AEMT)

Volume to be Administered:

The doctor orders you to administer 20 mg of a medication to the patient. The medication comes packaged as 25 mg/mL. How many mL will you administer?

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How to set it up:

Q (D/H) = Amount to give

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1 mL (20 mg / 25 mg) = __ mL

Answer explanation

Q (D/H) is the formula for determining the amount of medication you will deliver to your patient.

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(Quantity)(Desired/Have)

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Q- is the Quantity available. This will be the total mL volume of the medication container most often, but it could be “pill” or “tablet” or etc…

D- is the Desired amount. This is going to be the doctor’s order or amount of medication that you are wanting to calculate.

H- is the amount of medication that you Have available. This is going to be the mcg, mg, g amount that’s available inside of the container.

Volume to be Administered:

The doctor orders you to administer 98 mcg of a medication to the patient. The medication comes packaged as 5 mg/5 mL. How many mL will you administer?

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How to set it up:

Q (D/H) = Amount to give

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5 mL (98 mcg / 5000 mcg) = __ mL

Answer explanation

Q (D/H) is the formula for determining the amount of medication you will deliver to your patient.

.

(Quantity)(Desired/Have)

.

Q- is the Quantity available. This will be the total mL volume of the medication container most often, but it could be “pill” or “tablet” or etc…

D- is the Desired amount. This is going to be the doctor’s order or amount of medication that you are wanting to calculate.

H- is the amount of medication that you Have available. This is going to be the mcg, mg, g amount that’s available inside of the container.

Volume to be Administered:

The doctor orders you to administer 40 mg of a medication to the patient. The medication comes packaged as 3 mg/2 mL. How many mL will you administer?

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How to set it up:

Q (D/H) = Amount to give

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2 mL (40 mg / 3 mg) = __ mL

Answer explanation

Q (D/H) is the formula for determining the amount of medication you will deliver to your patient.

.

(Quantity)(Desired/Have)

.

Q- is the Quantity available. This will be the total mL volume of the medication container most often, but it could be “pill” or “tablet” or etc…

D- is the Desired amount. This is going to be the doctor’s order or amount of medication that you are wanting to calculate.

H- is the amount of medication that you Have available. This is going to be the mcg, mg, g amount that’s available inside of the container.

Desired Dose and Volume to be Administered (combined):

The doctor orders you to administer 5 mg/kg of a medication to the patient. The patient weighs 92 kg and he medication comes packaged as 100 mg/2 mL. How many mL will you administer?

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How to set it up:

Step 1:

(Dose)(Weight)

(5 mg)(92 kg) = 460 mg

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Step 2:

Q (D/H) = Amount to give

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2 mL (460 mg / 100 mg) = __ mL

Answer explanation

Q (D/H) is the formula for determining the amount of medication you will deliver to your patient.

.

(Quantity)(Desired/Have)

.

In this example we have to calculate the desired dose becaouse the order is written as a weight based dose.

.

Q- is the Quantity available. This will be the total mL volume of the medication container most often, but it could be “pill” or “tablet” or etc…

D- is the Desired amount. This is going to be the doctor’s order or amount of medication that you are wanting to calculate.

H- is the amount of medication that you Have available. This is going to be the mcg, mg, g amount that’s available inside of the container.

Desired Dose and Volume to be Administered (combined):

The doctor orders you to administer 2.5 mg/kg of a medication to the patient. The patient weighs 44 lbs and the medication comes packaged as 500 mg/5 mL. How many mL will you administer?

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How to set it up:

Step 1:

44 lbs / 2.2 = 20 kg

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Step 2:

(Dose)(Weight)

(2.5 mg)(20 kg) = 50 mg

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Step 3:

Q (D/H) = Amount to give

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5 mL (50 mg / 500 mg) = __ mL

Answer explanation

Q (D/H) is the formula for determining the amount of medication you will deliver to your patient.

.

(Quantity)(Desired/Have)

.

In this example we have to calculate the weight in kg as well as the desired dose, because the order is written as a weight based dose.

.

Q- is the Quantity available. This will be the total mL volume of the medication container most often, but it could be “pill” or “tablet” or etc…

D- is the Desired amount. This is going to be the doctor’s order or amount of medication that you are wanting to calculate.

H- is the amount of medication that you Have available. This is going to be the mcg, mg, g amount that’s available inside of the container.

Amount to be Administered:

A medication requires a dose of 0.03 g. The medication is available in 10 mg tablets. How many tablets should be administered?

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How to set it up:

Q (D/H)= Amount to give

.

1 tablet (30 mg / 10 mg) = _ tablets

Answer explanation

Q (D/H) is the formula for determining the amount of medication you will deliver to your patient.

.

(Quantity)(Desired/Have)

.

Q- is the Quantity available. This will be the total mL volume of the medication container most often, but it could be “pill” or “tablet” or etc…

D- is the Desired amount. This is going to be the doctor’s order or amount of medication that you are wanting to calculate.

H- is the amount of medication that you Have available. This is going to be the mcg, mg, g amount that’s available inside of the container.

Amount to be Administered:

A medication requires a dose of 750 mg. The medication is available in 500 mg tablets. How many tablets should be administered?

.

How to set it up:

Q (D/H) = Amount to give

.

1 tablet (750 mg / 500 mg) = _ tablets

Answer explanation

Q (D/H) is the formula for determining the amount of medication you will deliver to your patient.

.

(Quantity)(Desired/Have)

.

Q- is the Quantity available. This will be the total mL volume of the medication container most often, but it could be “pill” or “tablet” or etc…

D- is the Desired amount. This is going to be the doctor’s order or amount of medication that you are wanting to calculate.

H- is the amount of medication that you Have available. This is going to be the mcg, mg, g amount that’s available inside of the container.

Fluid Infusion Rate (gravity):

The doctor orders you to administer 100 mL of NS to be delivered over 15 minutes. How many gtt/min will you set your 10 gtt/mL administration set at?

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How to set it up:

(Volume)(Drip Factor)

Time (in min)

= Flow Rate

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100 mL X 10 gtt/mL

15 minutes

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= __ gtt/min

Answer explanation

(Volume)(Drip Factor)

Time (in min)

is the formula for calculating an IV fluid infusion rate using a gravity drip set.

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Volume: is usually the size of the IV bag but if giving less that the entire bag you will calculate using the actual volume that you'll be giving.

NOTE: The safest practice is if you are giving less than the entire bag of IVFs, waste the amount not needed prior to initiating. This will eliminate any chance of fluid overload.

Drip Factor: is the size of the drip set (Ex: 10 gtt/mL, 15 gtt/mL, 60 gtt/mL)

Time: is the total number of minutes that the infusion/drip will run.

Fluid Infusion Rate (gravity):

The doctor orders you to administer 100 mL/hr of NS during transfer of the patient. How many gtt/min will you set your 20 gtt/mL administration set at?

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How to set it up:

(Volume)(Drip Factor)

Time (in min)

= Flow Rate

.

100 mL X 20 gtt/mL

60 minutes

.

= __ gtt/min

Answer explanation

(Volume)(Drip Factor)

Time (in min)

is the formula for calculating an IV fluid infusion rate using a gravity drip set.

.
Volume: is usually the size of the IV bag but if giving less that the entire bag you will calculate using the actual volume that you'll be giving.

NOTE: The safest practice is if you are giving less than the entire bag of IVFs, waste the amount not needed prior to initiating. This will eliminate any chance of fluid overload.

Drip Factor: is the size of the drip set (Ex: 10 gtt/mL, 15 gtt/mL, 60 gtt/mL)

Time: is the total number of minutes that the infusion/drip will run.

Desired Dose:

A patient weighs 154 lbs. The medication prescribed is 2 mg/kg. How many mg should the patient receive?

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How to Set it Up:

Step 1: 154 / 2.2= 70 kg

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Step 2: 2 mg (70 kg)

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= __ mg

Answer explanation

If the desired dose is based on the patient's weight. All you have to do is multiply the dose by the weight in kg. If the patient's weight is only known in pounds you will have to convert to kg by dividing the weight by 2.2.