70356097 dosage calculation

SAME version 2.1. - 1 - Haspela 2004

SAME Safe Administration of

Medications Exam

A Review of Dosage Calculations, Preparation, and Administration

Version 2.1

Created by Dean N. Haspela BS,CES; BS,RN University of Massachusetts Boston

College of Nursing and Health Sciences

The Safe Administration of Medication Exam (SAME) is designed to assess

your ability to safely prepare medications and calculate drug dosages.

Success on the SAME depends on learning from the text book,

attendance at a med/math review session and review with this packet.

For information about med/math review sessions:

Look online at www.cnhs.umb.edu, check your email, or the bulletin boards

outside of CNHS.

Table of Contents Math Review

Fractions, Decimals, and Rounding………… 2-4 Conversions………………………………… 5 Ratio-Proportions…………………………… 6 Basic Problem Solving and Resources……… 7

Adult Medication Administration Review Oral Medications: Tablets and Capsules…… 8-11 Oral Medications: Liquids and Elixers……… 12-13 Injections: Types, Sizes, Amounts, Sizes…… 14-15 Injections: Calculations……………………… 16-17 Intravenous Medications: Drip and Pump Rates 18-21

Pediatrics Conversions…………………………………… 23-24 24 Hour Dose Calculations…………………… 25 Divided Doses………………………………… 26 Therapeutic Ranges…………………………… 27 Basic Problem Solving and Salient Pediatric Tips 28 Pediatric IV Calculations……………………….. 29 Reconstitution…………………………………… 30

Appendix Prohibited Medical Abbreviations……………… 31

Answers to Practice Problems………………….. 32-68


Fractions and Decimals

Nurses need to understand fractions to be able to understand and implement medication orders.

A fraction is used to describe a portion of a number.

For example: 1/8 means 1 of 8 pieces 5/60 means 5 of 60 pieces

Remember that any number over the same number is equal to one.

For example: 60/60 = 1 4/4 = 1

Remember that any number over 1 is equal to that number. For example: 60/1 is the same as 60 25/1 = 25 You can convert a fraction into a decimal by dividing the bottom number (denominator) into the top number (numerator).

For example: 1/2 = 0.5 because 2 goes into 1 0.5 times or 1 divided by 2 is equal to 0.5

1/4 = 0.25 because 4 goes into 1 0.25 times or 1 divided by 4 is equal to 0.25

Example 3/25 is equal to ____ of 25 pieces? The numerator describes how many parts there are in

the denominator. So, 3/25 means 3 of 25 pieces. 250/250 is equal to ____? Any number over that same number is equal to 1. So, 250/250 = 1. 1/4 is equal to: a) 4 b) 0.5 c) 1 d) 0.25 A fraction can be expressed as a decimal by dividing the denominator into the numerator. So, when you

divide 4 into 1 you get d) 0.25

You Try… 1) 2/50 is equal to ____. 2) 4/1 is equal to ____. 3) 60/60 is equal to ____. 4) 1/2 is equal to ____. 5) 25/400 is equal to ____. 6) 15/60 is equal to ____.


Example 125.00 x 10 = 1250.0 325.50 / 10 = 32.550 450.677 x 1000 = 450677 1546.286 / 1000 = 1.546286

Hint: Let the zeros be your guide. When multiplying by a factor of 10 (10, 100, 1,000, 10,000,

etc…) the number of spaces the decimal point moves is equal to the number of zeros you see after the one.

Just remember that divide means to the left and multiply means to the right!

You Try… 7) 350.60 x 10 = ____. 8) 4.256 / 100 = ____. 9) 500 / 1000 = ____. 10) 125.5 x 100 = ____.

Decimals When you are working with decimals you should think of the decimal point as the divider between whole amounts and fractional amounts. X X X X . X X X X If you multiply any number by 10 the result is the same as moving the decimal place to the right one place.

For example: 250.50 x 10 = 2505.0

• If you multiply any number by 100 you will need to move the decimal point 2 places to the right.

• If you multiply any number by 1000 you will need to move the decimal point 3 places to the right.

If you divide any number by 10 the result is the same as moving the decimal place to the left one place For example: 125.25 / 10 = 12.525

• If you divide any number by 100 you will need to move the decimal point 2 places to the left.

• If you divide any number by 1000 you will need to move the decimal point 3 places to the left.

Ten thousandths Thousandths H

undreths Tenths D

ecimal Point

Ones

Tens H

undreds Thousands


Rounding Sometimes a number has many numbers to the right of the decimal point. So, we use rounding to make the number easier to use. Remember: in this review packet we always use decimals out to the hundredths point. Any result that has thousandths or more needs to be rounded. For example: 10.054 needs rounding 255.25 does not need rounding Look for the thousandths.

• Find the number in the thousandths place. This is the number that is 3 places to the right of the decimal place.

• Round UP: round up if the number is greater than or equal to 5

• Round DOWN: round down if the number is less than 5. When you decide to round down the number in the hundredths place just stays the same.

• Examples

2.256 = 2.26 You round up in this example. The 6 is in the

hundredths place and is greater than or equal to 5…so…round the 5 up to a 6 and the answer is 2.26.

10.542 = 10.54 You round down in this example. The 2 is in the hundredths place and is less than 5…so…the 4 that is in hundredths place stays the same and the answer is 10.54.

Example 100.257 needs to be rounded up to 100.26 1.24 is a number out to the hundredths so it should not be rounded 2.542 needs to be rounded down to 2.54 60.255 needs to be rounded up to 60.26

You Try… 11) 500.259 = ____. 12) 285.001 = ____. 13) 1.2555 = ____. 14) 45.509 = ____.


Conversions Medications are often ordered in larger or smaller units than those held in stock. So, as a nurse you will need to convert metric units.

1 gram (g) = 1000 milligrams (mg) 1 milligram (mg) = 1000 micrograms (mcg) 1 microgram (mcg) = 0.001 milligrams (mg)

1 milligram (mg) = 0.001 gram (g)

The nurse will frequently need to convert metric measurements into household measurements to help patients understand how to take medications or so that the nurse can understand what the patient is describing. 2.2 pounds (lb) = 1 kilogram(kg)

1 tablespoon (tbsp) = 15 milliliters(ml) 3 teaspoons(tsp) = 15 milliliters(ml) 1 cup(C) = 240 milliliters(ml) 8 ounces(oz) = 240 milliliters(ml) 1 teaspoon(tsp) = 5 milliliters(ml) 1 cup(C) = 8 ounces(oz) 16 ounces(oz) = 1 pound(lb) 1 ouncs(oz) = 30milliliters(ml)

DON’T FORGET!! When referring to volumes you

will see cc and/or ml – REMEMBER that 1ml = 1cc. You will see these units used interchangeably.

THROUGHOUT THIS PACKET WE WILL USE ml

Example ORDER: Give 0.005mg levothyroxine PO once daily STOCK: 10mcg tablets of levothyroxine GIVE: ½ tablet one daily by mouth ORDER: Give 2T tussin PO every eight hours STOCK: 500ml bottle of tussin GIVE: 30ml every 8 hours by mouth ORDER: Give 0.5mg lorazepam PO three times a day STOCK: 1mg tablets of lorazepam GIVE: ½ tablet of lorazepam 3 times a day by mouth Your patient says they weigh 124 pounds. How many kilograms is this? 124lbs/ 2.2 = 56.36kg

You Try… 15) How many pounds is 60kg? 16) How many kg is 225lbs? 17) How many ml are there in ½ cup? 18) How many ml are there in 4oz.? 19) How many mg are there in 24g? 20) How many mcg are there in 0.5mg?


Ratio-Proportions A ratio is a comparison of two numbers. For example, the ratio of 1 to 4 is most often represented by the fraction ¼. Another example of a ratio is 5 to 6 and this is most often represented by the fraction 5/6. A ratio might be used by a nurse to explain a relationship between two things. For example, for every 1 tablet there are 5 milligrams. This might be written as a ratio like this:

1 tab 5mg

When two ratios are compared to each other it is called a proportion. A proportion looks like two fractions with an equal sign between them. A proportion might look like this:

1 = 4 4 16

Remember – because there is an equal sign between the two fractions the fractions are equal to each other. In the above example – this means that ¼ is equivalent to 4/16.

If one piece of information is missing you can use a proportion to solve a problem by cross-multiplying.

For example: QUESTION: In one pill there are 4mg.

So, how many pills make 16 mg? 1) Set up a proportion 1 = X_ like this 4 16 2) Cross multiply like this: (4) x (X) = (1) x (16) 3) Solve for X like this: X = (1) x (16) 4 4) The answer is then: X = 4

Example In 3mL there are 6mg of Morphine Sulfate. How many mg are there in 1mL?

1) Set up a proportion 3ml = 1ml_ like this: 6mg Xmg 2) Cross multiply like this: (3) x (X) = (1) x (6)

3) Solve for X like this: X = (1) x (6) 3 4) The answer is then: X = 2

REMEMBER: When you are setting up a proportion the units of numerators must match and the units of the denominators must match. If they don’t you CAN NOT proceed. In the above example ml is the numerator in both ratios and mg is the denominator in both ratios.

You Try… 21) How many mg are in 3ml if 1ml has 5mg? 22) If there are 25mg in one tablet then how many mg are there in 3 tablets? 23) In one tablet there is 100mg. How many pills make up 50mg? 24) How many mg are there in 10ml if 1ml has 2.5mg?


Basic Problem Solving and Resources There are 4 basic steps to solving any medication problem.

1) Read. 2) Stop & Think. 3) Solve. 4) Check & Question.

• READ Read the whole question or medication order.

• STOP & THINK What is this question asking? What is the order asking to administer? Is the order complete?

Is there missing or extra information? • SOLVE Solve the problem by using the correct formula or proportion. Go slow. Write out your work. • CHECK & Check your answer for accuracy. QUESTION Does the answer make sense? Is the answer feasible? Use common sense. There are many resources available to you to help check and question your answers. Some of these include:

Drug Reference Books Physician’s Desk Reference (PDR) Pharmacy/Pharmacist Checking with another Nurse Checking with a Clinical Instructor

Example

• A nurse draws up 50 units of regular insulin into a syringe and has another nurse verify that it was done correctly prior to administration.

• A nurse calculates the rate to set an IV pump at. Before starting the pump she has a pharmacist verify that the rate calculation is correct.

• A nurse reads a medication order and determines that 12 tablets need to be given. Because this number seems odd and unlikely, she checks a drug reference book and finds that the order was written incorrectly. The ordering physician is then contacted to correct and clarify the incorrectly written order.

In fourteen-hundred-ninety-two… …Columbus sailed the ocean blue.

How did he get so smart anyway? He did it by following basics of problem solving. He

thought about his questions, solved them carefully, and was not afraid to question the feasibility of his answers.


Oral Medications: Tablets and Capsules Ratio-Proportion Method

The oral form of medications is the most commonly prescribed type. It includes tablets, capsules, and liquid medications.

• The safest practice is to administer the fewest number of undivided tablets as possible.

• Capsules are not intended to be cut or split. The capsule dose must match the ordered dose.

You can solve tablet and capsule problems by using ratios and proportions.

REMEMBER: When you are setting up a proportion the units of numerators must match and the units of the denominators must match. If they don’t you CAN NOT proceed. (i.e. you might need to convert grams to milligrams or pounds to kilograms so that the units will match)

For example: ORDER: 50mg Toprol XL PO once daily

STOCK: Toprol XL tablets labeled 25mg

1) Set up a proportion 1 tab = X tab_ like this 25mg 50mg 2) Cross multiply like this: (25) x (X) = (1) x (50) 3) Solve for X like this: X = (1) x (50) 25 4) The answer is then: X = 2 tablets

Example

ORDER: Decadron 1.5mg PO twice a day STOCK: tablets labeled 0.75mg How many tablets do you administer?

1) Set up a proportion _1 tab = X tab_ like this 0.75mg 1.5mg 2) Cross multiply like this: (0.75) x (X) = (1) x (1.5) 3) Solve for X like this: X = (1) x (1.5) 0.75 4) The answer is then: X = 2 tablets

You Try… 25. ORDER: prednisone 10mg PO three times a day

STOCK: tablets labeled 2.5mg How many tablets do you administer?

26. ORDER: Tylenol 650mg PO every eight hours STOCK: tablets labeled 325mg How many tablets do you administer?

27. ORDER: digoxin 0.125mg PO at 4pm daily STOCK: tablets labeled 0.25mg (scored) How many tablets do you administer?

28. ORDER: diphenhydramine 50mg PO every 8 hours

STOCK: capsules labeled 25mg How many capsules do you administer?


Oral Medications: Tablets and Capsules Formula Method

Some people prefer to use a formula instead of using the ratio-proportion method. This page shows you how to do the exact same problems/examples by using a formula. Regardless of using the ratio-proportion method or the formula method – you will get the exact same answer. Try both ways and then stick with the one that works best for you.

The formula that you will need is:

_D_ x Q = Correct dose to administer H D = Desired dose or doctor’s order

H = The strength that you have or the strength on the container Q = The unit the drug is manufactured in

Consider this example… ORDER: 50mg Toprol XL PO QD STOCK: Toprol XL tablets labeled 25mg

50mg x 1 whole tablet = 2 tablets 25mg

The answer is: administer 2 tablets of Toprol XL by mouth once daily.

Example ORDER: Decadron 1.5mg PO twice a day STOCK: tablets labeled 0.75mg How many tablets do you administer?

_D_ x Q = Correct dose to administer H

1.5mg x 1 whole tablet = 2 tablets 0.75mg

ANSWER: Administer 2 tablets twice a day by mouth

Tip: Q or the unit the drug comes in will always be 1 when using tablets or capsules. The stock for oral solid drugs is always 1.

You Try… 29. ORDER: prednisone 10mg PO three times a day

STOCK: tablets labeled 2.5mg How many tablets do you administer?

30. ORDER: Tylenol 650mg PO every 8 hours STOCK: tablets labeled 325mg How many tablets do you administer?

31. ORDER: digoxin 0.125mg PO at 4pm daily STOCK: tablets labeled 0.25mg (scored) How many tablets do you administer?

32. ORDER: diphenhydramine 50mg PO every 8 hours

STOCK: capsules labeled 25mg How many capsules do you administer?


Oral Medications: Tablets and Capsules Formula Method

Did you notice something about all the examples on the last 2 pages? All the measurements were in the same system of measure. Unfortunately, when nurses interpret drug orders the units ordered may not match the units you have on hand. Consider this problem… ORDER: synthroid 300mcg PO once a day STOCK: tablets labeled 0.1mg (scored) How many tablets will you administer? Notice that the units ordered are in mcg and the units in stock are mg. Before you can use the formula you must first convert into the same units of measure. You can do this by using a proportion. First, remember that there are 1000mcg in 1 mg. Second, set up a proportion to solve for x like this… 1000mcg = X mcg 1mg 0.1mg Third, cross multiply like this… (1000mcg) x (0.1mg) = (1mg) x (X mcg) Fourth, Solve for X like this… Fifth, (1000 mcg) x (0.1mg) = X = 100 mcg 1mg Sixth, Now that the units are in the same measure you

can use the formula to get the answer - just like you did on the last page. (See example to the top right)

Example

ORDER: synthroid 300mcg PO once daily STOCK: tablets labeled 0.1mg (scored) How many tablets will you administer?

First, convert to same units of measure 1000mcg = X mcg then….1000 mcg x 0.1mg = X = 100 mcg 1mg 0.1mg 1mg

Now that the units are the same you can solve the problem. If you use the formula is will look like this:


300mcg x 1 whole tablet = 3 tablets 100mcg

ANSWER: Administer 3 tablets once a day by mouth

You Try…

33. ORDER: amoxicillin 1.5g PO every 8 hours STOCK: capsules labeled 250mg How many capsules do you administer?

34. ORDER: ethchlorvynol 2000mg PO at bedtime STOCK: capsules labeled 1g How many capsules do you administer?

35. ORDER: digoxin 0.5mg PO once a day STOCK: tablets labeled 125mcg How many tablets do you administer?

36. ORDER: carvedilol 6.25mg PO twice a day STOCK: capsules labeled 6250mcg How many capsules do you administer?


Oral Medications: Tablets and Capsules Ratio-Proportion Method

Once again – you can solve using either the ratio-proportion method or the formula method. This page uses the exact same examples as on the last page but uses the ratio-proportion method to solve.

Consider this problem… ORDER: synthroid 300mcg PO once a day STOCK: tablets labeled 0.1mg (scored) How many tablets will you administer? Notice that the units ordered are in mcg and the units in stock are mg. Before you can use the formula you must first convert into the same units of measure. You can do this by using a proportion. First, remember that there are 1000mcg in 1 mg. Second, set up a proportion to solve for x like this… 1000mcg = X mcg 1mg 0.1mg Third, cross multiply like this… 1000mcg x 0.1mg = 1mg x X mcg Fourth, Solve for X like this… Fifth, 1000 mcg x 0.1mg = X = 100 mcg 1mg Sixth, Now that the units are in the same measure you

can use the formula to get the answer - just like you did on the last page. (See example to the top right)

Example

ORDER: synthroid 300mcg PO once daily STOCK: tablets labeled 0.1mg (scored) How many tablets will you administer? First, convert to same units of measure 1000mcg = X mcg then….1000 mcg x 0.1mg = X = 100 mcg 1mg 0.1mg 1mg

Now that the units are the same you can solve the problem. If you use the ratio-proportion method is will look like this:

1) Set up a proportion _1 tab = X tab_ like this 100mcg 300mcg 2) Cross multiply like this: (100) x (X) = (1) x (300) 3) Solve for X like this: X = (1) x (300) 100 4) The answer is then: X = 3 tablets

You Try…

37. ORDER: amoxicillin 1.5g PO every 8 hours STOCK: capsules labeled 250mg How many capsules do you administer?

38. ORDER: ethchlorvynol 2000mg PO at bedtime STOCK: capsules labeled 1g How many capsules do you administer?

39. ORDER: digoxin 0.5mg PO once daily STOCK: tablets labeled 125mcg How many tablets do you administer?

40. ORDER: carvedilol 6.25mg PO twice daily STOCK: capsules labeled 6250mcg How many capsules do you administer?


Oral Medications: Liquids and Elixers Ratio-Proportion Method

Calculations for liquids and elixirs can be solved in the same manner as with tablets and capsules. You can use either the ratio-proportion method or the formula method. On this page we review the ratio-proportion method. Don’t forget to make sure that the units in the numerators are the same and the units in the denominators are the same. Consider this example… ORDER: cloxacillin sodium 0.25g PO every 6 hours STOCK: cloxacillin sodium 125mg per 5ml How many ml do you administer? First, convert to same units of measure 1000mg = X mg then….1000mg x 0.25g = X = 250mg 1g 0.25g 1g

Then, solve the problem using the ratio-proportion method:

1) Set up a proportion _5ml = X ml_ like this 125mg 250mg 2) Cross multiply like this: (125) x (X) = (5) x (250) 3) Solve for X like this: X = (5) x (250) 125 4) The answer is then: X = 10 ml

Example

ORDER: amoxicillin oral suspension 500mg PO Q8H STOCK: amoxicillin oral suspension 1g per 10ml How many ml do you administer? First, convert to same units of measure: 1000mg = X mg then….1000mg x 1g = X = 1000mg 1g 1g 1g Then, solve the problem using the formula

1) Set up a proportion _10ml = X ml_ like this 1000mg 500mg 2) Cross multiply like this: (1000)x(X) = (10)x(500) 3) Solve for X like this: X = (10) x (500) 1000 4) The answer is then: X = 5 ml

You Try… 41. ORDER: hydrocortisone cypionate oral

suspension 0.03g PO every 6 hours STOCK: liquid labeled 10mg per 5ml How many ml do you administer?

42. ORDER: cephalex in oral suspension 0.35g PO every 6 hours

STOCK: liquid labeled 125mg per 5ml How many ml do you administer?

43. ORDER: erythromycin susp. 0.75g PO 4 times a day


44. ORDER: penicillin V potassium 0.6g PO every 6 hours



Oral Medications: Liquids and Elixers Formula Method

This page presents the exact same examples and practice problems as on the last page, but uses the formula method instead of the ratio-proportion method.

The formula that you will need is:


H = The strength that you have or the strength on the container Q = Unit the drug is manufactured in

Remember: When calculating doses for liquids and elixirs the unit that the drug comes in (Q) will change. Read the label to determine these values. (An example of this might be 10mg in 2ml or 250mg in 500ml)

Consider this example. ORDER: cloxacillin sodium 0.25g PO every 6 hours STOCK: cloxacillin sodium 125mg per 5ml How many ml do you administer? First, convert to same units of measure 1000mg = X mg then….1000mg x 0.25g = X = 250mg 1g 0.25g 1g Then, solve the problem using the formula

250mg x 5ml = 10ml 125mg

Example

ORDER: amoxicillin oral suspension 500mg PO every 8 hours

STOCK: amoxicillin oral suspension 1g per 10ml How manyml do you administer? First, convert to same units of measure 1000mg = X mg then….1000mg x 1g = X = 1000mg 1g 1g 1g

Then, solve the problem using the formula

500mg x 10ml = 5ml 1000mg

ANSWER: Administer 5ml of the oral suspension by

You Try… 45. ORDER: hydrocortisone cypionate oral

susp. 0.03g PO once every 6 hours STOCK: liquid labeled 10mg per 5ml How many ml do you administer?

46. ORDER: cephalex in oral suspension 0.35g PO every 6 hours


47. ORDER: erythromycin susp. 0.75g PO 4 times a day


48. ORDER: penicillin V potassium 0.6g PO every 6 hours



Injections: Types, Sizes, Amounts, and Sites

All syringes generally have the same appearance. The parts include:

• Syringe itself with gradations/lines on it • Needle (some screw on or push on) • Plunger • Safety guard (some needles have a system that covers

the needle after it’s use to prevent needle sticks)

Remember that different syringes have different gradations!

Here’s a look at syringes based on sites, sizes, and volumes.

Syringe Size

Needle Guage

Needle Length

Maximum Injectable Volume

SQ 1ml, U50 insulin, or

U100 insulin syringes

25 – 27 guage

3/8 – 5/8 inches 0.5 – 1ml

IM 2-5ml for

adult and 1-2ml for child

19 – 23 guage

1 – 1½ inches

Adult:3ml Child or

small adult:2ml

Small children:1ml

ID 1ml tuberculin syringe

26 – 27 guage

3/8 – 5/8 inches 0.1 – 0.3 ml

You Try… 49. True or False:

Administer 1ml SQ with a 5ml syringe that is 3/8 inches and 26 guage

50. True or False:

Administer 25units insulin with a U100 syringe that is 3/8 inches in length and 27 guage

51. True or False:

Administer a TB test by injecting 0.2ml of test solution with a 1ml tuberculin syringe that is 5/8 inches in length and 26 guage

52. True or False: Administer 3ml SQ to an adult using a 1 ½ inch needle that is 20 guage

Example

1) True or False: Administer 2ml IM to a 2 month old infant. 2) True or False: Administer 1.5ml IM with a 1 ½ inch, 26

guage needle. 3) True or False: Administer 0.25ml SQ with a 3/8 inch needle that is 26 guage 4) True or False: Administer 0.5ml IM with a 1 ½ inch 20 guage needle 5) True or False: Administer 0.5ml ID with a 3/8 inch needle that is 26 guage 6) True or False: Administer 3ml to an adult with a 1ml syringe that is 1 inch in length and 19 guage Answers: 1) F 2) F 3) T 4) T 5) F 6) F


Injections Liquid medications are sterile solutions or suspensions. Sterile technique must be maintained when preparing injections. Each syringe has different gradations on it.

In a 1ml syringe, each gradation equals 0.01ml.

In a 3ml syringe, each gradation equals 0.1ml.

Insulin syringes come in two types. Each line in a U-50 syringe is equal to 1 unit and the whole syringe holds 0.5ml. Each line in a U-100 syringe is equal to 1 unit and the whole syringe holds 1ml.

Please note that due to computerized formatting the lines on some of these examples may be inaccurate.

You Try… 53. Mark 1.2ml on the following syringe.

54. Mark 12 units on the following syringe.

55. Mark 0.75ml on the following syringe

Example 2.5ml is marked on the following syringe.

0.25ml is marked on the following syringe.

88 Units is marked on the following syringe.


Injections: Ratio-Proportion Method

You can use either the ratio-proportion method or the formula method to solve injection problems. This page demonstrates the ratio-proportion method. Try it this way and then try it using the formula method on the next page. Choose the one that works the best for you and stick with that one method.

ORDER: 5mg Morphine Sulfate IM STOCK: liquid labeled 10mg per 1ml

1) Set up a proportion 1 ml = X ml_ like this 10mg 5mg 2) Cross multiply like this: (10) x (X) = (1) x (5) 3) Solve for X like this: X = (1) x (5) 10 4) The answer is then: X = ½ml or 0.5ml

ANSWER: Administer 0.5ml of intramuscular morphine

sufate. Select a 1 to 3 ml syringe for precision.

Tip: Selecting the Correct Syringe Sizes. • The best syringe to use will closely match the

volume of fluid you are administering. Remember that the degree of accuracy when calculating injections is based on the syringe used.

• Only use large syringes with large volumes. Larger syringes have fewer gradation lines and therefore are less precise.

• Only use small syringes with small volumes. Smaller syringes have more gradation lines and therefore are able to deliver very precise amounts.

Example

ORDER: metoprolol 25mg IV push stat STOCK: ampule labeled 50mg per 5 ml How many ml will you draw up into a syringe? What size syringe is ideal?

1) Set up a proportion 5 ml = X ml_ like this 50mg 25mg 2) Cross multiply like this: (50) x (X) = (5) x (25) 3) Solve for X like this: X = (5) x (25) 50 4) The answer is then: X = 2.5 ml

ANSWER: Administer 2.5 ml of metoprolol IV push now.

Use a 3ml syringe.

You Try… 56. ORDER: meperidine 75mg IM every 4 hours STOCK: meperidine 50mg per ml How many ml will you draw up into a syringe? 57. ORDER: phenergan 15mg IM every 4-6 hours PRN; nausea STOCK: PHENERGAN 50mg per ml How many ml will you draw up into a syringe? 58. ORDER: nebcin 60mg IV every 8 hours STOCK: nebcin 80mg per 2ml How many ml will you draw up into a syringe? 59. ORDER: vitamin B12 1000micrograms IM once a day STOCK: vitamin B12 5000 micrograms per 1ml

How many ml will you draw up into a syringe?


Injections: Formula Method This page shows the exact same examples as on the last page but it uses the formula method to solve the problems.

The formulas that you will need is:


H = The strength that you have or the strength on the container Q = Unit the drug is manufactured in

ORDER: 5mg Morphine Sulfate IM STOCK: liquid labeled 10mg per 1 ml

5mg x 1ml = 0.5 ml 10mg

ANSWER: Administer 0.5 ml of intramuscular morphine sufate. Select a 1 to 3 cc syringe for precision.

Tip: Selecting the Correct Syringe Sizes.

• The best syringe to use will closely match the volume of fluid you are administering. Remember that the degree of accuracy when calculating injections is based on the syringe used.

• Only use large syringes with large volumes. Larger syringes have fewer gradation lines and therefore are less precise.

• Only use small syringes with small volumes. Smaller syringes have more gradation lines and therefore are able to deliver very precise amounts.

Example

ORDER: metoprolol 25mg IV push stat STOCK: ampule labeled 50mg per 5 ml How many ml will you draw up into a syringe? What size syringe is ideal?

25mg x 5 ml = 2.5 ml 50mg

ANSWER: Administer 2.5 ml of metoprolol IV push now

You Try… 60. ORDER: meperidine 75mg IM every 4 hours STOCK: meperidine 50mg per ml How many mL will you draw up into a syringe? 61. ORDER: phenergan 15mg IM every 4 – 6 hours

PRN; nausea STOCK: PHENERGAN 50mg per ml How many ml will you draw up into a syringe? 62. ORDER: nebcin 60mg IV every 8 hours STOCK: nebcin 80mg per 2ml How many ml will you draw up into a syringe? 63. ORDER: vitamin B12 1000micrograms IM once a day STOCK: vitamin B12 5000 micrograms per 1 ml How many ml will you draw up into a syringe?


Intravenous Medications: Drip Rates Intravenous (IV) medications are more complex because they require the nurse to administer the correct dosages over the correct amount of time. One way to regulate the infusion of an IV medication is by calculating the number of drops per minute. This is called the drip rate.

An IV medication order usually includes three parts: 1) the type of medication to be administered 2) the volume of medication ordered 3) the amount of time the IV medication is to be administered over (i.e. over 2 hours)

The formula you will need is:

_V_ x DF = Drip Rate T V = The volume ordered in ml T = The number of minutes that the infusion is to be completed in

DF = The drop factor (rate indicated on the tubing you are using)

ORDER: 250 ml of NS over 60 minutes TUBING: 15gtt/ml What is the drip rate you will set? Set up the problem using the formula above. 250 ml is the volume. 60 min is the time in minutes. 15gtt/ml is the drop factor of the tubing that you are using.

250ml x 15gtt = 62.5 or 63 gtt per minute 60min 1ml

ANSWER: Adjust the roller clamp on the IV line to a rate of 63 drops per minute. This will administer a total of 250 ml in about 60 minutes.

Example ORDER: 450ml of ½ NS over 6 hours TUBING: 15gtt/ml What is the drip rate you will set? First convert the hours to minutes like this: 6 hours x 60 minutes = 360 minutes Then plug the numbers into the formula:

450 ml x 15gtt = 18.75 or 19 gtts per minute 360min 1ml

In this example the time (T) was 6 hours. Remember that you need to convert this to minutes when plugging the numbers into the formula. 6 hours x 60 minutes = 360 minutes.

The answer 18.75 gtts was rounded up to 19 gtts. You must round the answer to the nearest whole number because it is impossible to count fractions or portions of drops.

You Try…

64. ORDER: 2 L of NS over 24 hours TUBING: 10gtt/ml What is the drip rate you will set? 65. ORDER: 250ml of NS over 30 minutes TUBING: 15gtt/ml What is the drip rate you will set? 66. ORDER: 1 gram of Magnesium Sulfate in 100ml of NS over 2 hrs TUBING: 60gtt/ml What is the drip rate you will set?


Intravenous Medications: Drip Rates

Frequently intravenous medication orders are written to infuse over a large number of hours. This can make the math difficult – especially if you are unable to use a calculator. This page shows you how to simplify the numbers so that the math is a bit easier. This is done by adding one step. Lets consider this problem… ORDER: 450 ml of ½ normal saline over 6 hours TUBING: 15gtts / ml What is the drip rate that you will set? First. Determine ml / hr like this: 450 ml = 75 ml / hour

6 hours Second. Use the formula that is shown on the last page:

_V_ x DF = Drip Rate T V = The volume ordered in ml T = The time the infusion is to occur over

DF = The drop factor (rate indicated on the tubing)

75 ml x 15 gtts = 18.75 gtts 60 min ml min Third. Round 18.75 up to 19 gtts / min

REMEMBER: You can use the method described on this page OR the method described on the last page. The only difference is that there is less calculation to do. Pick the

one that is easier for you and stick with it!

Example ORDER: 3000 ml of D10W over 24 hours TUBING: 15 gtts / ml What is the drip rate that you will set? First. Determine ml / hr like this: 3000 ml = 125 ml / hour

24 hours Second. Use the formula like this:

V_ x DF = Drip Rate T

125 ml x 15 gtts = 31.25 gtts 60 min ml min Third. Round 31.25 down to 31 gtts / min

You Try…

67. ORDER: 4000ml of Lactated Ringers over 24 hours TUBING: 15 gtts / ml What is the drip rate that you will set? 68. ORDER: 2000ml of Normal Saline over 10 hours TUBING: 15 gtts / ml What is the drip rate that you will set? 69. ORDER: 2000ml of ½ Normal Saline over 6 hours TUBING: 10 gtts / ml What is the drip rate that you will set? 70. ORDER: 4000ml of Lactated Ringers over 48 hours TUBING: 10 gtts / ml What is the drip rate that you will set?


Intravenous Medications: Pump Rates Pumps are frequently used in the hospital setting because they safely administer a medication at a reliable and consistent rate. Pumps offer the ability to strictly regulate the infusion.

The most common type of pump requires that you perform calculations so that they determine the number of ml that are infused over an hour. This is called the pump rate.

IV medications to be administered with pumps contain 3 parts:

1) the type of medication to be administered 2) the volume of medication ordered 3) the amount of time the IV medication is to be administered over (i.e. over 2 hours)

The formula you will need is:

_V_ = Pump Rate T V = The volume ordered in ml T = The number of hours that the infusion is to be completed in

PR = Pump rate in ml/hour

ORDER: NS 250ml IV over the next 2 hours by infusion

pump 250 ml = x ml 2 hours hour

ANSWER: x = 125 ml/hour. You should set the pump rate to 125 ml per hour.

Example

ORDER: 150 ml of ½ NS over 20 minutes How many ml/hour will you set the pump at? 1) Use the formula like this: 150ml = Pump rate 20min The answer is then 7.5 ml/minute.

2) REMEMBER that the pump needs to be set to ml/hour. The answer that we just got is in ml/minute. You MUST convert to ml/hour like this:

7.5 ml x 60 minutes = 450ml min hour ANSWER: Set the pump rate at 450 ml/hour. This will

administer 150 ml of ½ NS over 20 minutes.

You Try… What would you set the pump rate (ml/hour) in the following examples? 71. ORDER: 1 gram of vancomycin over 60 minutes STOCK: 2 grams of vancomycin in 500ml of NS 72. ORDER: 2 grams of magnesium sulfate IV over

20 minutes STOCK: 2000mg of magnesium sulfate in 100ml 73. ORDER 50mg furosemide per hour IV STOCK: 500mg furosemide in 250ml bag of NS 74. ORDER: cefmetazole 4grams IV over 30

minutes STOCK: cefmetazole 4 grams in 100ml of NS


Intravenous Medications: Pump Rates Sometimes when you read an order for an IV medication that requires the use of a pump you will first need to determine the volume. Consider this example… ORDER: 1000 units of heparin an hour STOCK: 250ml bag containing 25,000 units of heparin First, remember the formula:

_V_ = PR (ml/hr) T V = The volume ordered in ml T = The number of hours that the infusion is to be completed in

PR = Pump rate in ml/hour Next, notice that first you must determine the volume (V) ordered in ml. This order asks us to administer 1000 units of heparin. Use a proportion to figure this out

_250 ml = X ml_ 25,000 units 1000 units

(250 ml) x (1000 units) = (25,000 units) x (X ml) (250 ml) x (1000 units) = x x = 10 ml 25,000 units Finally, plug in your answer to the formula above. _10 ml_ = 10 ml/hour 1 hour ANSWER: Set the pump at 10 ml / hour.

Example

ORDER: 1300 units of Heparin an hour STOCK: 250 ml bag containing 25,000 units of heparin First determine how many ml you will need. Use a proportion to figure this out:

_250 ml = __X ml__ 25,000 units 1300 units

250 ml x 1300 units = 25,000 units x X ml

250 ml x 1300 units = x x = 13 ml 25,000 units Finally, plug in your answer to the formula above. _13 ml_ = 13 ml/hour

1 hour

You Try… What would you set the pump rate (ml/hour) in the following examples?

75. ORDER: 1200 units of heparin per hour STOCK: 250 ml bag containing 25,000 units of

heparin 76. ORDER: 1550 units of heparin per hour

STOCK: 250 ml bag containing 25,000 units of heparin

77. ORDER: 3 units an hour of insulin STOCK: 100 units of insulin in 100 ml bag of NS 78. ORDER: 2 grams of Magnesium Sulfate over 2

hours STOCK: 2 grams of Magnesium Sulfate in

100 ml of D5W


SAME

A Review of Dosage Calculations, Preparation, and Administration

Version 2.1

PEDIATRIC FOCUS

University of Massachusetts Boston College of Nursing and Health Sciences

www.cnhs.umb.edu

Administration of medications to children and infants can be tricky. Here are a few tips:

Don’t forget the 6 rights: patient, drug, dose, route, time, documentation.

With pediatrics, the dose is frequently based on

weight. This means that you may need to calculate the correct dose of medication for each pediatric patient.

Household measurements (like tbsp., cups, or ounces)

are frequently used. You may need to convert measures to metric while doing calculations.

Pediatric patients can’t be expected to take the same

amounts of elixirs or the same size pills as adults. Find out if the pharmacy has more appropriate pill and elixir concentrations for your pediatric patients.

Pediatric intravenous medications are calculated in the

same way that you calculate for an adult, except, pediatrics frequently uses tubing that is 60gtts/ml instead of 15gtts/ml or 10gtts/ml.

Pumps help the nurse to ensure precision in IV

medication administration to pediatrics. They are commonly used.


PEDIATRICS: Conversions Pediatric drug calculations commonly use household measurement. Therefore, it is important that the nurse understand how to convert between household units and metric units.

Remember these household conversions:

2.2 pounds (lbs) = 1 kilogram(kg)

16 ounces(oz) = 1 pound(lb)

1milliliter (ml) = 1cc

1 tablespoon (tbsp) = 15 milliliters (ml)

3 teaspoons(tsp) = 15 milliliters(ml)

1 cup(C) = 240 milliliters(ml)

8 fluid ounces(oz) = 240 milliliters(ml)

1 teaspoon(tsp) = 5 milliliters(ml)

1 cup(C) = 8 fluid ounces(oz)

1 fluid ounce(oz) = 30 milliliters (ml)

Example

1. A mother says she gave her child 1 ½ tablespoons of robitussion. How many ml is this?

1 tbsp = 1.5 tbsp (1.5) x (15) = 22.5ml 15ml Xml 1

2. A doctors order explains that a child should drink 240 ml

of Pedialyte 4 times a day. How might you easily tell a parent to follow these instructions?

Since there are 240 ml in one cup it might be

easier for a parent to know that their child needs to drink 4 cups of Pedialyte a day

instead of 960 ml a day.

You Try…

79. There are _____ml in 1 ½ cups 80. There are _____ml in 3 teaspoons 81. 15ml is the same as _____ teaspoons or ______ tablespoons 872. There are _____ ounces in 1 pound and _____ml in 16 ounces 83. _____ ounces is equal to 375ml


PEDIATRICS: Conversions The most accurate and common way to calculate pediatric dosages is by using mg/kg/day. Often a child’s weight is recorded in pounds and ounces. Therefore, you must first convert the ounces to pounds and then convert pounds to kilograms.

Remember the following conversion factors: There are 16 ounces in a pound.

There are 2.2 pounds in 1 kilogram. For example. Consider a child who is 14 pounds 4 ounces. How many kilograms is this child?

2. First, you need to convert ounces to pounds by dividing the number of ounces by the number 16 (because there are 16 ounces in a pound):

4 ounces = 0.25 pounds

16 3. Add 0.25 pounds to 14 pounds to get 14.25

pounds. 4. Third, you need to convert pounds to kilograms.

We just figured out that 14 pounds 4 ounces is the same thing as saying 14.25 pounds. So, divide this by 2.2 to find out how many kilograms the child weighs.

14.25 pounds = 6.477 kilograms 2.2 5. Finally, round off to two decimal places and the

correct answer is 6.48 kilograms.

Example

How many kilograms is equal to 45 pounds 2 ounces?

1. Convert the ounces like this: 2/16 = 0.125 2. Add 0.125 to 45 to get 45.125 pounds 3. Convert to kilograms like this: 45.125/2.2 4. Answer: 20.511 kilograms. Round to 20.51kg

Convert 24 pounds 15 ounces to kilograms.

1. Convert the ounces like this: 15/16 = 0.937 2. Add 0.937 to 24 pounds to get 24.937 pounds

2. Convert to kilograms like this: 24.937/2.2 3. Answer: 11.335 kilograms. Round to 11.34kg

You Try…

84. 8 pounds 4 ounces = ______ pounds divide by 2.2 = _______ kg

85. 20 pounds 8 ounces = ______ pounds

divide by 2.2 = ______ kg 86. 18 pounds 7 ounces = ______ pounds

divide by 2.2 = ______ kg 87. 41 pounds 5 ounces = ______ pounds

divide by 2.2 = _______ kg


PEDIATRICS: Maximum 24 Hour Doses

Because pediatric medications are based on weight, drug reference books list the maximum dose that is safe to administer in one day – a 24 hour period of time.

The maximum 24 hour dose is NOT the amount that you may actually give at any one time – instead it is the MAXIMUM SUM or MAXIMUM TOTAL of all the divided doses given that day that can safely be given.

After determining the maximum 24 hour dose the nurse will then calculate the amount to be given in each dose. (For example, if BID dosing is preferred the 24 hour dose will be divided by two.)

Pediatric orders which are written in mg/kg/day require us to first convert from pounds to kilograms and then to determine how much drug should be given based on the weight.

For example: Consider a child who weighs 21 pounds 6 ounces and medication is ordered at 15mg/kg/day.

1. First convert to pounds plus ounces to pounds

6 ounces/16 = 0.375 pounds add 0.375 pounds to 21=21.375pounds

2. Second, convert to kilograms 21.375/2.2 = 9.715 kg

3. Next determine how much medication a day should be given

(15 mg) x (9.715 kg) = 145.725 mg/day

4. Now round this to 2 decimal places. 145.73mg/day 5. The nurse next determines if the dosage is safe by

comparing ordered and recommended dosages. Recommended dosages are found in a drug reference book.

Example

A child weighs 11 pounds 3 oz. A medication is ordered at 20mg/kg/day. The safe range for this medication is up to 200mg/kg/day. 11 pounds 3 ounces = 11.188 pounds 11.188 pounds / 2.2 = 5.085 kilograms

(20mg) x (5.085 kg) = 101.7 mg / day

101.7 mg/day is within the safe range of this medication.

Remember: 200mg/day is the MAXIMUM that is safe to be given in one day or within a 24 hour period. It is NOT the amount that you actually administer. To determine how much to give the patient you must read the order to see how many times it is to be given in a day, and calculate the divided dose. See next pg.

You Try…

88. The child weighs 21 pounds and 6 ounces. The max that can be given in 24 hours is 80 mg/kg/day. The max 24 hour dose dose for this child is _____ mg/day.

89. The child weighs 42 pounds and 12 ounces. The max

that can be given in 24 hours is is 100 mg/kg/day. The max 24 hour dose dose for this child is ____ mg/day.


that can be given in 24 hours is 20 mg/kg/day. The max 24 hour dose dose for this child is ____ mg/day.


that can be given in 24 hours is 40 mg/kg/day. The max 24 hour dose dose for this child is mg/day.


PEDIATRICS: Divided Dosages On the last pages you learned how to calculate daily dosages based on weight. This calculation is important but medications are usually given in divided doses a few times during the day. It is easy to do this. You simply need to divide the mg/day by the number of times a day that the medication is going to be administered. For example: You are working with a 55 pound child and a medication is ordered at 75mg/kg/day and is to be given in 3 divided doses.

1. First convert from pounds to kilograms: 55pounds/2.2 = 25kg

2. Next you should calculate the pounds per kilogram per day:

(75mg) x (25kg) = 1875mg/day

3. Finally, you should calculate the mg in each dose by dividing the daily dose by 3:

(1875mg) / 3 = 625 mg 3 times a day

Example

For example: You are working with a 54 pound 9 ounce child and a medication is ordered at 100mg/kg/day and is to be given in 2 divided doses.

1. First convert from pounds to kilograms: 9 ounces / 16 = 0.562 pounds 54 + 0.562 = 54.562 pounds 54.562 pounds/2.2 = 24.8kg

2. Next you should calculate the pounds per kilogram per day:

(100 mg) x (24.8 kg) = 2480 mg/day

3. Finally, you should calculate the mg in each dose by dividing the daily dose by 2:

(2480 mg) / 2 = 1240 mg 2 times a day

You Try…

92. The child weighs 50 kg. The medication is 10 mg/kg/day given in 3 divided doses. Each dose is _________ mg.

93. The child weighs 22 pounds. The medication is 40 mg/kg/day given in 4 divided doses. Each dose is _________ mg.

94. The child weighs 12 pounds 8 ounces. The medication is 30 mg/kg/day given every 8 hours. The total mg dose per day is ______________ mg.

Each dose is _______ mg.

95. The child weighs 15 pounds 2 ounces. The medication is given 50 mg/kg/day given in 4 divided doses. Each dose is ________ mg.


PEDIATRICS: Therapeutic Ranges

Some medications have a range of mg/kg/day recommended (there is usually a maximum allowable total amount per day also specified).

Dosages that are over the recommended amounts can be dangerous.

Dosages that are under the recommended amount can also be dangerous because they are considered to be subtherapeutic.

Consider this example… • A drug reference book indicated that the safe

medication range for this medication is 25-35mg/kg/day. You are working with a 35 pound 4 ounce child.

• If a medication order asked you to give 425mg once, would you give it? Is 425mg a safe dose to give?

Solution: You will need to calculate two numbers (the minimum and maximum safe doses). Then, you can determine if the dose for this patient falls within the range (safe) or outside the range (unsafe).

1. Convert pounds and ounces to kg 4 ounces / 16 = 0.25 pounds 0.25 pounds + 35 pounds = 35.25 pounds 35.25 / 2.2 = 16.023 kg

2. Calculate the maximum and minimum doses: 3. Minimum of range:(16.023 kg) x (25mg) =

400.575 mg Maximum of range:(16.023 kg) x (35mg) = 560.875 mg

4. The order asked you to give 425mg to this 16.02kg child. Since 425mg falls between 400.575mg and 560.875 425mg is a safe dose to administer.

Example An order asks you to administer 50mg of a medication to a 6 pound 2 ounce premature infant via a PEG tube. A drug reference book indicated that the safe medication range for this medication is 10 – 15 mg/kg/day. Is 50mg a safe dose to give?

1. Convert to kilograms like this: 6 pounds 2 ounces 2 / 16 = 0.125 0.125 + 6 = 6.125 pounds 6.125 pounds / 2.2 = 2.784 kg

2. Calculate the maximum and minimum doses like this: Minimum of range: (2.784 kg) x (10 mg) = 27.84 kg Maximum of range: (2.784 kg) x (15 mg) = 41.76 kg

3. The order asked you to give 50mg to this 2.8kg child.

Since 50mg is greater than 42 (the maximum safe recommended dose) you should NOT give the medication.

This is not a safe dose.

You should contact the ordering physician to discuss modification to the order.

You Try…

You are working with a child who is 26.6kg. Calculate the maximum and minimum recommended doses for the following medications:

96. digoxin PO; 20 – 40 mc g/kg/day 97. paraldehyde IM; 0.15ml/kg/day; not to exceed 5ml/kg/day 98. Ritalin PO; 5mg before breakfast and lunch; increasing by 5-10mg/week; not to exceed 60mg/day 99. neomycin PO; 50-100mg/kg/day 100. ondasteron IV; up to 0.15mg/kg/day


PEDIATRICS: Tips and Pointers

If you work with an adult population for some time, it is likely that you will become very familiar with certain drugs, doses, and routes. It may become very easy for you to pick out discrepancies, errors, or inappropriate orders. However, it is somewhat different with pediatrics. Because doses are based on weight, doses will vary from patient to patient. Therefore, following the steps to basic problem solving becomes even more important: There are 4 basic steps to solving any medication problem.

1) Read. 2) Stop & Think. 3) Solve. 4) Check & Question.

• READ Read the whole question or medication order.

• STOP & THINK What is this question asking? What is the order asking to administer? Is the order complete?

Is there missing or extra information? • SOLVE Solve the problem by using the correct formula or proportion. Go slow. Write out your work. • CHECK & Check your answer for accuracy. QUESTION Does the answer make sense? Is the answer feasible? Use common sense.

Example Determine the maximum and minimum safe doses for the

medication in the order below. What is the total daily dose that the order is asking you to

administer? Is this dose safe? What would you do?

ORDER: Give 625mg of penicillin V potassium PO four times a day. You are working with a 75lb. child with a pneumococcal infection. A drug reference book states that the safe range is 15-50mg/kg/day.

1. 75lbs / 2.2 = 34.09kg 2. Minimum: (34.09kg) x (15mg) = 511.35mg

Maximum:(34.09kg) x (50mg) = 1704.5mg 3. Daily total in order: (625mg) x (4 doses) = 2500mg 4. 2500mg is greater than calculated maximum. This is NOT a safe dose. Call the ordering physician to discuss this order. DO NOT administer medication.

You Try… For the orders below: Determine the maximum and minimum safe doses for the

medication in the order below. What is the total daily dose that the order is asking you to

administer? Is this dose safe? What would you do?

101. ORDER: Give 125mg IV Bactrim three times a day. You are working with a 125lb. child with chronic bronchitis. A drug reference book states that the safe range is 15-20mg/kg/day. 102. ORDER: Give 125mg amoxicillin PO four times a day. You are working with a 52 pound 12 ounce child with a systemic infection. A drug reference book states that the safe range is 20-40mg/kg/day.


PEDIATRICS: Intravenous Medications

Calculating the drop factor or the pump rate in pediatrics is done in the same way as for adults.

The main difference with pediatrics is that 60gtt/ml tubing

is used more frequently. This allows the nurse to deliver more precise amounts of medication to the pediatric patient.

When you need to calculate the drip rate you will need to use this formula: _V_ x DF = Drip Rate

T V = The volume ordered in ml T = The number of minutes that the infusion is to be completed in

DF = The drop factor (rate indicated on the tubing you are using)

When you are going to use a pump to administer intravenous

medication you will need to use this formula: _V_ = Pump Rate (ml/hr)

T V = The volume ordered in ml T = The number of hours that the infusion is to be completed in

PR = Pump rate in ml/hour

Example ORDER: Bactrim 1 gram IV over 1 hour BID STOCK: 1000mg Bactrim in 100cc NS; 60gtt/ml tubing What is the drip rate you will set?

100ml x 60gtt = 100 gtts per minute 60min 1ml

ANSWER: Set the roller clamp to 100 gtts/minute

ORDER: Vancomycin 375mg IV over 30 minutes four times a day STOCK: 1875mg Vancomycin in 500ml of D5W. What will you set the pump at?

_100ml_ = x ml 0.5hours hours

ANSWER: x = 200 ml/hour.

You Try… 103. ORDER: Bactrim 0.25 grams IV over 30 minutes STOCK: 500mg Bactrim in 100ml NS; 60gtt tubing What is the drip rate you will set? 104. ORDER: Vancomycin 150mg IV over 60 minutes STOCK: 300mg Vancomycin in 100mL of D5W What will you set the pump at? 105. ORDER: NS 50ml IV over 30 minutes STOCK: NS 100ml; 60gtt tubing What is the drip rate you will set? 106. ORDER: Ancef 0.6g IV in 50ml D5NS over 20 min. STOCK: Ancef 1gram in 100ml What will you set the pump at?


PEDIATRICS: Reconstitution • Some medications are not stable for long periods of time

and therefore arrive on the unit ‘un-mixed.’ The nurse must ‘reconstitute’ a powdered medication prior to administering it through the IV. This is call reconstitution.

• In this type of medication problem the nurse must add a specific volume of dilutent to the powder in order to create a new solution which has a known concentration.

Consider this example:

ORDER: Penicilin G 800,000 units IV every 4 hours. STOCK: Vial that states, “Add 9.6 ml of sterile water to

the vial to yield 100,000 units / ml. How many ml will the nurse withdraw from the vial after it is

reconstituted as indicated on the label? 1) After the nurse adds 9.6 ml of sterile water to the vial the

concentration of the solution will be 100,000 units / ml. (This information is on the label)

2) The order calls for 800,000 units IV every 4 hours. 3) Set up a proportion to solve for X like this: 100,000 units = 800,000 units 1 ml X ml 4) Cross multiply and solve for X like this: (100,000 units) x (X ml) = (1 ml) x 800,000 units) (1 ml) x 800,000 units) = Xml 100,000 units 8 ml = X ANSWER: The nurse withdraws 8 ml from the bottle. (This

amount contains the ordered 800,000 units of Penicilin G.

Example ORDER: Penicillin G 200,000 units IV every 8 hours STOCK: Vial that states, “Add 9.6 ml of sterile water to

the vial to yield 100,000 units / ml. How many ml will the nurse withdraw from the vial after it is

reconstituted as indicated on the label? 1) Set up a proportion to solve for X like this: 100,000 units = 200,000 units 1 ml X ml 4) Cross multiply and solve for X like this: (100,000 units) x (X ml) = (1 ml) x 200,000 units) (1 ml) x 200,000 units) = Xml 100,000 units 2 ml = X ANSWER: The nurse withdraws 2 ml from the bottle. (This

amount contains the ordered 200,000 units.)

You Try… 107. ORDER: Cefobid 500 mg IM every 6 hours STOCK: Vial that states, “Add 2 ml of dilutent to

equal 2.4 ml of solution which contains 1 gram of cefobid.” How many ml will the nurse withdraw from the vial after it is reconstituted as indicated on the label?

108. ORDER: Oxacillin 500 mg IM every 6 hours STOCK: Vial that states, “Add 5.7 ml sterile water.

each 1.5 ml contains 250mg oxacillin.” How many ml will the nurse administer after it is reconstituted as indicated on the label?

109. ORDER: Nafcillin sodium 250 mg IM every 6 hours STOCK: Vial that states, “Add 3.4 ml of sterile or

bacteriostatic water. Each ml contains 1000mg of nafcillin. How many ml will the nurse withdraw from the vial after it is reconstituted as indicated on the label?


Prohibited Medical Abbreviations

Some medical abbreviations that you might see can be misleading. Therefore, JCAHO requirements are mandating changes to ensure safe written communication. Changing the use of these ‘confusing’ abbreviations will cut down on errors. This page reviews some commonly misused/misinterpreted abbreviations.

Unacceptable Abbreviation

Intended Meaning

Acceptable Alternative

MS or MSO4 Morphine sulfate Use “morphine sulfate”

MgSO4 Magnesium sulfate

Use “magnesium sulfate”

Trailing zeros: Zero written after decimal points (ex. 1.0mg)

1mg Do not use terminal zeros for doses expressed in whole units (Write “1mg”)

Missing leading zeros: Zero missing before decimal points (ex. .5mg)

0.5mg Always us zero before a decimal point when the dose is less than a whole unit (Write “0.5mg”

U Unit Use “unit” IU International Unit Use “unit” or

“international unit” ug microgram Use “mcg” QD Once daily Use “daily” or

“once daily” QOD Every other day Use “every other

day” Letter “d” (ex. x3d)

Days (times 3 days)

Use “days” or “doses”

TIW or tiw Three times a week

Do no use this abbreviation. Specify which days of the week,

Source: BIDMC 4/04

Example

DON’T

• Don’t write 10 U regular insulin

• Don’t write enteric coated aspirin 325mg PO QD

• Don’t write .25mg xanax

PO QD • Don’t write 5mg IM

MSO4 for complains of 8/10 pain

• Don’t write QOD

You Try… See if you can underline all the unacceptable abbreviations. There are 9 of them in the following short nursing note. 110. O2 @ 2L/minute NC, 2.0mg MS IV, 3 SL .3mg

nitroglycerine given every 5 minutes, and an EKG was done. No relief within this first 15 minutes. Patient continued to complain of 9/10 substernal pain. IV nitroglycerine was started and titrated up to 200.00ug/min. Blood glucose was checked and result was 350.0, therefore 10U regular insulin was given SC in the left abdomen. Lasix 40mg PO QOD changed to 40.0 mg IV now….

Example

DO

• DO write 10 units regular insulin

• Do write enteric coated aspirin 325mg once daily by mouth

• Do write 0.25mg xanax once daily by mouth

• Do write 5mg IM morphine sulfate for complains of 8/10 pain

• Do write every other day


SAME

Answers to practice problems. Additional practice problems.

Version 2.1

University of Massachusetts Boston College of Nursing and Health Sciences

www.cnhs.umb.edu

• This section includes the answers and solutions to the

“You Try…” problems that are found throughout this packet.

o The left side of each page lists the original question and provides the answer.

o The right side of each page demonstrates how the

answer was obtained. The mathematical work is done out for you to see.


1. 2/50 is equal to __0.04__. 2. 4/1 is equal to __4__. 3. 60/60 is equal to _1__. 4. 1/2 is equal to __0.5__. 5. 25/400 is equal to

__0.0625__. 6. 15/60 is equal to _0.25___.

7. 350.60 x 10 = 3506

8. 4.256 / 100 = 0.04256

9. 500 / 1000 = 0.5 10. 125.5 x 100 = 12550 11. 500.259 = 500.26 12. 285.001 = 285 13. 1.2555 = 1.26

1. 2 divided by 50 = 0.04 2. 4 divided by 1 = 4 3. 60 divided by 60 = 1 4. 1 divided by 2 = 0.5 5. 25 divided by 400 = 0.0625 6. 15 divided by 60 = 0.25 7. Multiplying by 10 moves the decimal place once to the right. 3506.00 8. Dividing by 100 moves the decimal place twice to the left. 0.04256 9. Dividing by 1000 moves the decimal place three places to the left. 0.5 10. Multiplying by 100 moves the decimal place two places to the right.

12550 11. The number in the thousandths place (9) is greater than or equal to 5,

therefore we round the hundredths place up from 5 to a 6. 500.26 12. The number in the thousandths place (1) is less than 5, therefore we

round down and leave the hundredths place number alone. 285 13. The number in the thousandths place (5) is greater than or equal to 5,

therefore we round the hundredths place up from 5 to a 6. 1.26


14. 45.509 = 45.51 15. How many pounds is 60kg? 132 lbs 16. How many kg is 225lbs? 102.27 lbs 17. How many ml are there in ½ cup? 120 ml

14. The number in the thousandths place (9) is greater than or equal to 5, therefore we round the hundredths place up from 0 to 1. 45.51 15. First. Remember the conversion factor: 1kg = 2.2lbs Second. Set up a proportion like this:

1 kg = 60 kg 2.2lbs X lbs

Third. Solve by cross multiplying. (1 kg) x (X lbs) = (2.2 lbs) x (60 kg) Fourth. Solve for X (2.2 lbs) x (60kg) = 132 lbs 1 kg 16. First. Remember the conversion factor: 1kg = 2.2lbs Second. Set up a proportion like this:

1 kg = X kg 2.2lbs 225 lbs

Third. Solve by cross multiplying. (1 kg) x (225 lbs) = (2.2 lbs) x (X kg) Fourth. Solve for X (225 lbs) x (1 kg) = 102.27lbs 2.2 kg 17. First. Remember the conversion factor: 1 cup = 240 ml Second. Set up a proportion like this:

1 cup = ½ cup 240ml X ml

Third. Solve by cross multiplying. (240 ml) x (0.5 cup) = (1 cup) x (X ml) Fourth. Solve for X (240 ml) x (0.5 cup) = 120 ml 1 cup


18. How many ml are there in 4oz.? 120 ml 19. How many mg are there in 24g? 24,000mg 20. How many mcg are there in 0.5mg? 500mcg

18. First. Remember the conversion factor: 8 oz. = 240 ml Second. Set up a proportion like this:

8 oz. = 4 oz. 240ml X ml

Third. Solve by cross multiplying. (240 ml) x (4 oz.) = (8 oz.) x (X ml) Fourth. Solve for X (240 ml) x (4 oz) = 120 ml 8 oz 19. First. Remember the conversion factor: 1 gram = 1000 mg Second. Set up a proportion like this:

1 gram = 24 grams 1000mg X mg

Third. Solve by cross multiplying. (1000mg) x (24 grams) = (1 gram) x (X mg) Fourth. Solve for X (1000mg) x (24 grams) = 24,000mg 1 gram 20. First. Remember the conversion factor: 1 mg = 1000 mcg Second. Set up a proportion like this:

1 mg = 0.5mg 1000mcg X mcg

Third. Solve by cross multiplying. (1000mcg) x (0.5mg) = (1 mg) x (X mcg) Fourth. Solve for X (1000mcg) x (0.5 mg) = 500mcg 1 mg


21. How many mg are in 3ml if 1ml has 5mg? 15ml 22. If there are 25mg in one tablet then how many mg are there in 3 tablets? 75 mg 23. In one tablet there is 100mg. How many pills make up 50mg? ½ tablet

21. First. Set up a proportion like this: 1 ml = 3 ml 5mg X mg

Second. Solve by cross multiplying. (5mg) x (3ml) = (1 ml) x (X mg) Third . Solve for X (5mg) x (3ml) = 15ml 1 ml 22. First. Set up a proportion like this:

25 mg = X mg 1 tablet 3 tablets

Second. Solve by cross multiplying. (25mg) x (3 tablets) = (1 tablet) x (X mg) Third . Solve for X (25mg) x (3 tablets) = 75 mg 1 tablet 23. First. Set up a proportion like this:

1 tablet = X tablet 100 mg 50 mg

Second. Solve by cross multiplying. (1 tablet) x (50 mg) = (100 mg) x (X tablet) Third . Solve for X (1 tablet) x (50mg) = ½ tablet 100mg


24. How many mg are there in 10 ml if 1ml has 2.5mg? 25 mg 25. ORDER: prednisone 10mg

PO three times a day

STOCK: tablets labeled 2.5mg

How many tablets do you administer? 4 tablets 26. ORDER: Tylenol 650mg

PO every eight hours

STOCK: tablets labeled 325mg

How many tablets do you administer? 2 tablets

24. First. Set up a proportion like this: 2.5 mg = X mg 1 ml 10 ml

Second. Solve by cross multiplying. (2.5 mg) x (10 ml) = (1 ml) x (X mg) Third . Solve for X (2.5 mg) x (10 ml) = 25 mg 1ml 25. First. Set up a proportion like this 1 tab = X tab

2.5 mg 10mg Second. Solve by cross multiplying.

(1 tab) x (10 mg) = (2.5 mg) x (X) Third. Solve for X (1 tab) x (10 mg) = 4 tablets 2.5 mg

26. . First. Set up a proportion like this 1 tab = X tab

325 mg 650mg Second. Solve by cross multiplying.

(1 tab) x (650 mg) = (325 mg) x (X) Third. Solve for X (1 tab) x (650 mg) = 2 tablets 325 mg


27. ORDER: digoxin 0.125mg

PO at 4pm daily STOCK: tablets labeled

0.25mg (scored) How many tablets do you administer? ½ tablet 28. ORDER: diphenhydramine

50mg PO every 8 hours

STOCK: capsules labeled 25mg

How many capsules do you administer? 2 capsules 29. ORDER: prednisone 10mg

PO 3 times a day STOCK: tablets labeled 2.5mg How many tablets do you administer? 4 tablets

27. First. Set up a proportion like this: 0.125 mg = 0.25 mg X tablets 1 tablet

Second. Solve by cross multiplying. (0.125 mg) x (1 tablet) = (X tablets) x (0.25mg) Third . Solve for X (0.125 mg) x (1 tablet) = 0.5 tablets 0.25 mg 28. First. Set up a proportion like this:

50 mg = 25 mg X capsules 1 tablet

Second. Solve by cross multiplying. (50 mg) x (1 capsule) = (X capsule) x (25mg) Third . Solve for X (50 mg) x (1 capsule) = 2 capsules 25 mg 29. First. Remember the formula


Second Plug in the numbers into the formula 10 mg x 1 tablet = 4 tablets 2.5 mg


30. ORDER: Tylenol 650mg

PO every 8 hours STOCK: tablets labeled

325mg How many tablets do you administer? 2 tablets 31. ORDER: digoxin 0.125mg

PO at 4pm daily STOCK: tablets labeled

0.25mg (scored) How many tablets do you administer? ½ tablet 32. ORDER: diphenhydramine

50mg PO every 8 hours

STOCK: capsules labeled 25mg

How many tablets do you administer? 2 capsules

30. First. Remember the formula _D_ x Q = Correct dose to administer

H Second Plug in the numbers into the formula 650 mg x 1 tablet = 2 tablets 325 mg 31. First. Remember the formula


Second Plug in the numbers into the formula 0.125 mg x 1 tablet = 1/2 tablets 0.25 mg 32. First. Remember the formula


Second Plug in the numbers into the formula 50 mg x 1 capsule = 2 capsules 25 mg


33. ORDER: amoxicillin 1.5g

PO every 8 hours STOCK: capsules labeled

250mg How many capsules do you administer? 6 capsules 34. ORDER: ethchlorvynol

2000mg PO at bedtime

STOCK: capsules labeled 1g

How many tablets do you administer? 2 capsules

33. First. Convert g to mg so that the units in the problem match Do this by setting up a proportion like this:

1.5 g = 1 g X mg 1000 mg

Second. Solve for X like this: (1.5g) x (1000mg) = 1500 mg Dose ordered 1g in mg

Third. Remember the formula _D_ x Q = Correct dose to administer

H Fourth Plug in the numbers into the formula 1500 mg x 1 capsule= 6 capsules 250 mg 34. First. Convert mg to g so that the units in the problem match

Do this by setting up a proportion like this: 2000mg = 1000mg

X g 1g Second. Solve for X like this: (2000mg )x(1g) = 2g Dose ordered 1000mg in g


H Fourth Plug in the numbers into the formula 2g x 1 capsule= 2 capsules

1 g



PO once daily STOCK: tablets labeled

125mcg How many tablets do you administer? 4 tablets 36. ORDER: carvedilol

6.25mg PO twice a day

STOCK: capsules labeled 6250 mcg

How many tablets do you administer? 1 capsule

35. First. Convert mg to mcg so that the units match Do this by setting up a proportion like this:

1 mg = 0.5 mg 1000mcg X mcg

Second. Solve for X like this: (1000mcg) x (0.5mg) = 500 mcg Dose ordered 1mg in mcg


H Fourth Plug in the numbers into the formula 500mcg x 1 tablet = 4 tablets 125 mcg 36. First. Convert mg to mcg so that the units match

Do this by setting up a proportion like this: 1 mg = 6.25 mg

1000mcg X mcg Second. Solve for X like this: (1000mcg) x (6.25mg) = 6250mcg Dose ordered 1mg in mcg


H Fourth Plug in the numbers into the formula 6250mcg x 1 capsule= 1 capsule 6250 mcg


37. ORDER: amoxicillin 1.5g

PO every 8 hours STOCK: capsules labeled

250 mg How many tablets do you administer? 6 capsules 38. ORDER: ethchlorvynol

2000mg PO at bedtime

STOCK: capsules labeled 1g

How many capsules do you administer? 2 capsules

37. First. Convert g to mg so that the units match Do this by setting up a proportion like this:

1 g = 1.5 g 1000mg X mg

Second. Solve for X like this: (1000mg) x (1.5g) = 1500 mg Dose ordered 1g in mg Third. Now that the units match. Solve the problem by setting up a proportion like this: 1500mg = 250 mg

X capsules 1 capsule Fourth. Solve by cross multiplying.

(1500mg) x (1 capsule) = (X capsule) x (250mg) Fifth. Solve for X (1500mg) x (1 capsule) = 6 capsules 250 mg 38. First. Convert g to mg so that the units match

Do this by setting up a proportion like this: 1 g = X g

1000mg 2000 mg Second. Solve for X like this: (2000mg) x (1g) = 2 g Dose ordered 1000mg in grams Third. Now that the units match. Solve the problem by setting up a proportion like this: 2 g = 1 g

X capsules 1 capsule Fourth. Solve by cross multiplying.

(2 g) x (1 capsule) = (X capsule) x (1 g) Fifth. Solve for X (2 g) x (1 capsule) = 2 capsules 1 g



PO once a day STOCK: tablets labeled

125mcg How many tablets do you administer? 4 tablets 40. ORDER: carvedilol

6.25mg PO twice daily

STOCK: capsules labeled 6250mcg

How many capsules do you administer? 1 capsule

39. First. Convert mg to mcg so that the units match Do this by setting up a proportion like this:

1 mg = 0.5 mg 1000mcg X mcg

Second. Solve for X like this: (1000mcg) x (0.5mg) = 500mcg Dose ordered 1mg in mcg Third. Now that the units match. Solve the problem by setting up a proportion like this: 500 mcg = 125 mcg

X tablets 1 tablet Fourth. Solve by cross multiplying.

(500mcg) x (1 tablet) = (X tablets) x (125 mcg) Fifth. Solve for X (500mcg) x (1 tablet) = 4 tablets 125 mcg 40. First. Convert mg to mcg so that the units match

Do this by setting up a proportion like this: 1 mg = 6.25 mg

1000mcg X mcg Second. Solve for X like this: (1000mcg) x (6.25mg) = 6250mcg Dose ordered 1mg in mcg Third. Now that the units match. Solve the problem by setting up a proportion like this: 6250 mcg = 6250 mcg

X capsule 1 capsule Fourth. Solve by cross multiplying.

(6250mcg) x (1 capsule) = (X capsule) x (6250 mcg) Fifth. Solve for X (6250mcg) x (1 capsule) = 1 capsule 6250 mcg


41. ORDER: hydrocortisone

cypionate oral susp. 0.03 g PO every 6 hours

STOCK: liquid labeled 10mg per 5ml

How many ml do you administer? 15ml 42. ORDER: cephalex in oral

suspension 0.35g PO every 6 hours


How many ml do you administer? 14 ml

41. First. Convert from g to mg so the units match Do this by setting up a proportion like this: 0.03g = 1 g X mg 1000mg Second: Solve for X like this: (0.03g) x (1000mcg) = 30mg Dose ordered 1g in mg

Third. Solve the problem by setting up a proportion like this: 30 mg = 10 mg

X ml 5 ml Fourth. Solve by cross multiplying.

(30 mg) x (5 ml) = (X ml) x (10 mg) Fifth. Solve for X (30 mg) x (5 ml) = 15ml 10 mg 42. First. Convert from g to mg so the units match Do this by setting up a proportion like this: 0.35g = 1 g X mg 1000mg Second: Solve for X like this: (0.35g) x (1000mg) = 350mg Dose ordered 1g in mg Third. Solve the problem by setting up a proportion like this: 350 mg = 125 mg


(350 mg) x (5 ml) = (X ml) x (125 mg) Fifth. Solve for X (350 mg) x (5 ml) = 14 ml 125 mg


43. ORDER: erythromycin

susp. 0.75g PO four times a day


How many ml do you administer? 15 ml 44. ORDER: penicillin V

potassium 0.6 g PO every 6 hours


How many ml do you administer? 12ml

43. First. Convert from g to mg so the units match Do this by setting up a proportion like this: 0.75g = 1 g X mg 1000mg Second: Solve for X like this: (0.75g) x (1000mg) = 750mg Dose ordered 1g in mg Third. Solve the problem by setting up a proportion like this: 750 mg = 250 mg


(750 mg) x (5 ml) = (X ml) x (250 mg) Fifth. Solve for X (750 mg) x (5 ml) = 15 ml 250 mg 44. First. Convert from g to mg so the units match Do this by setting up a proportion like this: 0.6g = 1 g X mg 1000mg Second: Solve for X like this: (0.6g) x (1000mg) = 600mg Dose ordered 1g in mg Third. Solve the problem by setting up a proportion like this: 600 mg = 250 mg


(600 mg) x (5 ml) = (X ml) x (250 mg) Fifth. Solve for X (600 mg) x (5 ml) = 12 ml 250 mg


45. ORDER: hydrocortisone

cypionate oral susp. 0.03g PO every 6 hours


How many ml do you administer? 15 ml 46. ORDER: cephalex in oral

suspension 0.35g PO every 6 hours




1 g = 0.03g 1000mg X mg

Second. Solve for X like this: (1000 mg) x (0.03g) = 30 mg Dose ordered 1g in mg


H Fourth Plug in the numbers into the formula 30 mg x 5 ml = 15ml 10 mg 46. First. Convert g to mg so that the units match

Do this by setting up a proportion like this: 1 g = 0.35g

1000mg X mg Second. Solve for X like this: (1000 mg) x (0.35g) = 350 mg Dose ordered 1g in mg


H Fourth Plug in the numbers into the formula 350 mg x 5 ml = 14 ml 125 mg


47. ORDER: erythromycin

susp. 0.75g PO four times a day


How many ml do you administer? 15 ml 48. ORDER: penicillin V

potassium 0.6g PO every 6 hours

STOCK: liquid labeled 250 mg per 5 ml



1 g = 0.75g 1000mg X mg

Second. Solve for X like this: (1000 mg) x (0.75g) = 750 mg Dose ordered 1g in mg


H Fourth Plug in the numbers into the formula 750 mg x 5 ml = 15ml 250 mg 48. First. Convert g to mg so that the units match

Do this by setting up a proportion like this: 1 g = 0.6 g

1000mg X mg Second. Solve for X like this: (1000 mg) x (0.6 g) = 600 mg Dose ordered 1g in mg


H Fourth Plug in the numbers into the formula 600 mg x 5 ml = 12 ml 250 mg


49. True or False: Administer 1ml SQ with a 5 ml syringe that is 3/8 inches and 26 gauge 50. True or False: Administer 25units insulin with a U100 syringe that is 3/8 inches in length and 27 gauge 51. True or False: Administer a TB test by injecting 0.2ml of test solution with a 1ml tuberculin syringe that is 5/8 inches in length and 26 gauge 52. True or False: Administer 3ml SQ to an adult using a 1 ½ inch needle that is 20 gauge 53. Mark 1.2cc on the following syringe.

49. False. Administer SQ medications with a 1ml syringe. The needle gauge and length are correct.

50. True. 51. True. 52. False. Maximum volume with SQ injections is 1ml. Maximum

needle length for a SQ injection is 5/8 inches. Minimum needle gauge for a SQ injection is 25


54. Mark 12 units on the following syringe. 55. Mark 0.75 on the following syringe 56. ORDER: meperidine 75mg

IM every 4 hours STOCK: meperidine 50mg

per ml How many ml will you draw up into a syringe? 1.5 ml

54.

55.

56. First. Set up a proportion like this:

75 mg = 50 mg X ml 1 ml

Second. Solve by cross multiplying. (75 mg) x (1 ml) = (50 mg) x (X ml) Third. Solve for X (75 mg) x (1 ml) = 1.5ml 50mg


57. ORDER: Phenergan 15mg

IM every 4 – 6 hours PRN; nausea

STOCK: Phenergan 50mg per ml

How many ml will you draw up into a syringe? 0.3 ml 58. ORDER: nebcin 60mg IV

every 8 hours STOCK: nebcin 80mg per

2ml How many mL will you draw up into a syringe? 1.5ml 59. ORDER: vitamin B12 1000

micrograms IM once a day

STOCK: vitamin B12 5000 micrograms per 1ml

How many ml will you draw up into a syringe? 0.2 ml

57. First. Set up a proportion like this: 15 mg = 50 mg X ml 1 ml

Second. Solve by cross multiplying. (15 mg) x (1 ml) = (50 mg) x (X ml) Third. Solve for X (15 mg) x (1 ml) = 0.3ml 50mg 58. First. Set up a proportion like this:

60 mg = 80 mg X ml 2 ml

Second. Solve by cross multiplying. (60 mg) x (2 ml) = (80 mg) x (X ml) Third. Solve for X (60 mg) x (2 ml) = 1.5ml 80mg 59. First. Set up a proportion like this:

1000 mcg = 5000 mcg X ml 1 ml

Second. Solve by cross multiplying. (1000 mcg) x (1 ml) = (5000 mcg) x (X ml) Third. Solve for X (1000 mcg) x (1 ml) = 0.2ml 5000 mcg


60. ORDER: meperidine 75mg IM every 4 hours STOCK: meperidine 50mg per ml How many ml will you draw up into a syringe? 1.5 ml 61. ORDER: phenergan 15 mg IM every 4 – 6 hours PRN; nausea STOCK: phenergan 50 mg per ml How many ml will you draw up into a syringe? 0.3 ml 62. ORDER: nebcin 60mg IV every 8 hours STOCK: nebcin 80mg per 2 ml How many ml will you draw up into a syringe? 1.5 ml


H Second. Plug in the numbers into the formula 75 mg x 1 ml = 1.5 ml 50 mg 61. First. Remember the formula


Second. Plug in the numbers into the formula 15 mg x 1 ml = 0.3 ml 50 mg 62. First. Remember the formula


Second. Plug in the numbers into the formula 60 mg x 2 ml = 1.5 ml 80 mg


63. ORDER: vitamin B12 1000

micrograms IM once daily

STOCK: vitamin B12 5000 micrograms per 1ml

How many ml will you draw up into a syringe? 0.2 ml 64. ORDER: 2 L of NS over 24

hours TUBING: 10gtt/ml What is the drip rate you will set? 14 gtts/min 65. ORDER: 250ml of NS over

30 minutes TUBING: 15gtts/ml What is the drip rate you will set? 125 gtts/ml


H Second. Plug the numbers into the formula 1000 mg x 1 ml = 0.2ml 5000 mg 64. First. Remember the formula

_V_ x DF = Drip Rate T

Second. Convert L to ml: 2L x 1000ml = 2000ml Convert hours to minutes: 24hours x 60min =

Third. Plug the numbers into the formula. 2000ml x 10gtt = 13.88gtts/min 1440min ml Fourth. Round up to 14 drops per minute. 65. First. Remember the formula


Second. Plug the numbers into the formula. 250ml x 15 gtts = 125 gtts/min 30min ml


66. ORDER: 1 gram of Magnesium

Sulfate in 100ml of NS over 2 hrs

TUBING: 60 gtts/ml What is the drip rate you will set? 50 gtts/min 67. ORDER: 4000ml of Lactated

Ringers over 24 hrs TUBING: 15 gtts / ml What is the drip rate you will set? 42 gtts / min 68. ORDER: 2000ml of Normal

Saline over 10 hours TUBING: 15 gtts / ml What is the drip rate you will set? 50 gtts / minute

66. First. Remember the formula V x DF = Drip Rate

T Second. Plug the numbers into the formula. 100 ml x 60 gtts = 50 gtts/min 120 min ml 67. First. Determine ml / hr like this: 4000 ml = 166.667 ml / hour ( Round to 167 ml / hr)



167 ml x 15 gtts = 41.75 gtts 60 min ml min Third. Round 41.75 up to 42 gtts / min 68. First. Determine ml / hr like this: 2000 ml = 200 ml / hour



200 ml x 15 gtts = 50 gtts 60 min ml min Third. 50 gtts / minute


69. ORDER: 2000ml of ½ Normal

Saline over 6 hours TUBING: 10 gtts / ml What is the drip rate you will set? 56 gtts / min 70. ORDER: 4000ml of Lactated

Ringers over 48 hours TUBING: 10 gtts / ml What is the drip rate you will set? 14 gtts / min

69. First. Determine ml / hr like this: 2000 ml = 333.333 ml / hour (Round to 333 ml / hr)



333 ml x 10 gtts = 55.5 gtts 60 min ml min Third. Round 55.5 up to 56 gtts / min 70. First. Determine ml / hr like this: 4000 ml = 83.333 ml / hour ( Round to 83 ml/ hr)



83. ml x 10 gtts = 13.83 gtts 60 min ml min Third. Round 13.83 up to 14 gtts / min


71. ORDER: 1 gram of

vancomycin over 60 minutes

STOCK: 2 grams of vancomycin in 500 ml of NS

What would you set the pump rate to? 250 ml/hour 72. ORDER: 2 grams of

magnesium sulfate IV over 20 minutes

STOCK: 2000mg of magnesium sulfate in 100 ml

What would you set the pump rate to? 300 ml/hr

71. First. Remember the formula V = Pump Rate (ml/hr)

T Second. Plug the numbers into the formula.

250 ml = 250 ml/hour 1 hour 72. First. Remember the formula

V = Pump Rate (ml/hr) T

Second. Plug the numbers into the formula. 100 ml = 5 ml/minute 20 minutes Third. Change from ml / minute to ml / hour like this: 5 ml x 60 min = 300ml/hour min hour


73. ORDER 50mg furosemide per hour IV STOCK: 500mg furosemide in 250 ml bag of NS What would you set the pump rate to? 25 ml/hour 74. ORDER: cefmetazole 4grams IV over 30 minutes STOCK: cefmetazole 4 grams in 100ml of NS What would you set the pump rate to? 200 ml/hour


T Second. Determine how many ml there are in one dose:

Set up a proportion like this: 50 mg = 500 mg X ml 250 ml

Third. Solve by cross multiplying. (50 mg) x (250 ml) = (X ml) x (500 mg) Fourth. Solve for X (50 mg) x (250 ml) = 25 ml 500 mg Fifth. Plug the numbers into the formula. 25 ml = 25 ml/hour 1 hours 74. First. Remember the formula


Second. Plug the numbers into the formula. 100 ml = 200ml/hour 0.5 hours


75. ORDER: 1200units of

Heparin per hour STOCK: 250ml bag

containing 25,000 units of heparin

What would you set the pump rate (cc/hour)? 12ml/hour 76. ORDER: 1550units of

Heparin per hour STOCK: 250ml bag

containing 25,000 units of heparin

What would you set the pump rate (cc/hour)? 15.5 ml/hour



Set up a proportion like this: 1200 units = 25,000 units X ml 250 ml

Third. Solve by cross multiplying. (1200 units) x (250 ml) = (X ml) x (25,000 units) Fourth. Solve for X (1200 units) x (250 ml) = 12ml 25,000 units Fifth. Plug the numbers into the formula. 12 ml = 12ml/hour 1 hours 76. First. Remember the formula


Second. Determine how many mL there are in one dose: Set up a proportion like this:

1550 units = 25,000 units X ml 250 ml

Third. Solve by cross multiplying. (1550 units) x (250 ml) = (X ml) x (25,000 units) Fourth. Solve for X (1550 units) x (250 ml) = 15.5ml 25,000 units Fifth. Plug the numbers into the formula. 15.5 ml = 15.5 ml/hour 1 hours


77. ORDER: 3 units an hour of

Insulin STOCK: 100 units of

insulin in 100ml bag of NS

What would you set the pump rate (ml/hour)? 3 ml/hour 78. ORDER: 2 g Magnesium

Sulfate over 2 hours

STOCK: 2 g Magnesium Sulfate in 100mL of D5W

What would you set the pump rate (ml/hour)? 50 ml/hour



Set up a proportion like this: 3 units = 100 units X ml 100 ml

Third. Solve by cross multiplying. (3 units) x (100 ml) = (X ml) x (100 units) Fourth. Solve for X (3 units) x (100 ml) = 3 ml 100 units Fifth. Plug the numbers into the formula. 3 ml = 3 ml/hour 1 hours 78. First. Remember the formula


Second. Plug the numbers into the formula. 100 ml = 50ml/hour 2 hours


79. There are 360 ml in 1 ½ cups 80. There are 15 ml in 3 teaspoons 81. 15ml is the same as 3 teaspoons or 1 tablespoon. 82. There are 16 ounces in 1 pound and 480 ml in 16 fluid ounces 83. 12.5ounces is equal to 375ml 84. 8 pounds 4 ounces = 8.25 pounds divide by 2.2 = 3.75 kg 85. 20 pounds 8 ounces = 20.5 pounds divide by 2.2 = 9.32 kg 86. 18 pounds 7 ounces = 18.438 pounds divide by 2.2 = 8.38 kg

79. 1 cup = 240 ml ½ of 240 is 120 80. 1 teaspoon = 5 ml 3 times 5ml = 15ml 81. 1 teaspoon = 5ml; 3 teaspoons = 1 tablespoon 3 times 5ml = 15ml 82. 16 ounces = 1 pound; 8 fluid ounces = 240 ml 1 times 16 ounces = 16 ounces; 240ml times two = 480ml 83. 1 ounce = 30 ml If you divide 375 by 30 = 12.5 ounces 84. First. Convert the ounces like this: 4/16 = 0.25 pounds Second. Add 0.25 to 8 = 8.25lbs

Third. Convert to kilograms like this: 8.25 pounds / 2.2 = 3.75 kg

85. First. Convert the ounces like this: 8/16 = 0.5 pounds Second. Add 0.5 to 20 = 20.5 pounds

Third. Convert to kilograms like this: 20.5 pounds / 2.2 = 9.32 kg


Third. Convert to kilograms like this: 18.438 pounds / 2.2 = 8.38 kg.


87. 41 pounds 5 ounces = 41.313 pounds divide by 2.2 = 18.78 kg 88. The child weighs 21

pounds and 6 ounces. The max that can be given in 24 hours is 80 mg/kg/day. The max 24 hour dose for this child is 777.28 mg/day.

89. The child weighs 42

pounds and 12 ounces. The max that can be given in 24 hours is is 100 mg/kg/day. The max 24 hour dose dose for this child is 1943.2 mg/day.


pounds and 3 ounces. The max that can be given in 24 hours is 20 mg/kg/day. The max 24 hour dose dose for this child is 510.8 mg/day.


Second. Convert to kilograms like this: 41.313 pounds / 2.2 = 18.779 kg. Round this to 2 places. 18.78 kg.

88. First. Convert the ounces like this: 6/16 = 0.375 Then add 0.375 + 21 = 21.375 Second. Convert to kilograms like this: 21.375 / 2.2 = 9.716 kg Third. (80 mg) x (9.716 kg) x (1 day) = 777.28 mg/day 89. First. Convert the ounces like this: 12/16 = 0.75 Then add 0.75 to 42 = 42.75 pounds Second. Convert to kilograms like this: 42.75 / 2.2 = 19.432 kg Third. (100 mg) x (19.432 kg) x (1 day) = 1943.2 mg/day 90. First. Convert the ounces like this: 3/16 = 0.188 Then add 0.188 to 56 = 56.188 pounds Second. Convert to kilograms like this: 56.188 / 2.2 = 25.54 kg Third. (20mg) x (25.54kg) x (1 day) = 510.8 mg/day


91. The child weighs 35 pounds and 2 ounces. The max that can be given in 24 hours is 40 mg/kg/day. The max 24 hour dose dose for this child is 638.64 mg/day.

92. The child weighs 50 kg.

The medication is 10 mg/kg/day given in 3 divided doses. Each dose is 166.67 mg.


pounds. The medication is 40 mg/kg/day given in 4 divided doses. Each dose is 100 mg.


pounds 8 ounces. The medication is 30 mg/kg/day given every 8 hours. The total mg per day is 170.46 mg. Each dose is 56.82 mg.

91. First. Convert the ounces like this: 2/16 = 0.125 Then add 0.125 to 35 = 35.125 Second. Convert to kilograms like this: 35.125 / 2.2 = 15.9766 kilograms Third. (40mg) x (15.966 kg) x (1 day) = 638.64 mg/day 92. First. (10mg) x (50kg) = 500mg a day Second. (500mg) / (3 times a day) = 166.67mg 93. First. Convert to kilograms like this: 22 / 2.2 = 10 pounds

Second. (40mg) x (10kg) = 400mg a day Third. (400mg) / (4 times a day) = 100mg 94. First. Convert ounces to pounds: 8/16 = 0.5 pounds Then add 0.5 to 12 = 12.5 pounds.

Second. Convert to pounds to kilograms like this: 12.5pounds / 2.2 = 5.682 kilograms

Third. (30mg) x (5.682kg) = 170.46 mg a day Fourth (170.46 mg) / (3 times a day) = 56.82 mg


95. The child weighs 15 pounds 2 ounces. The medication is given 50 mg/kg/day given in 4 divided doses. Each dose is 85.94 mg

96. digoxin PO; 20-40 mcg/kg/day 26.6kg child Max safe dose: 1064mcg/day Min safe dose: 532mcg/day 97. paraldehyde IM; 0.15ml/kg/day; not to exceed 5ml/kg/day 26.6kg child Max safe dose: 133ml/day Min safe dose: 3.99ml/day 98. Ritalin PO; 5mg before breakfast and lunch; increasing by 5-10mg/week; not to exceed 60mg/day 26.6kg child

95. First. Convert ounces to pounds: 2/16 = 0.125pounds Then add 0.125 to 15 pounds = 15.125

Second. Convert to pounds to kilograms like this: 15.125 / 2.2 = 6.875 kilograms

Third. (50 mg) x (6.875 kg) = 343.75 mg a day Fourth (343.75 mg) / (4 times a day) = 85.938mg Round this

to 85.94 mg for the final answer. 96. Max: (26.6kg) x (40mcg/kg/day) = 1064 mcg/day.

Min: (26.6kg) x (20mcg/kg/day) = 532mcg/day. 97. Max: (26.6kg) x (5ml/kg/day) = 133ml/day

Min: (26.6kg) x (0.15ml/kg/day) = 3.99mg/day 98. Min: The answer is in the problem – two 5mg doses. One before

breakfast and one before lunch. Max: The answer is in the problem – not to exceed 60mg/day

(regardless of childs weight).


99. neomycin PO; 50-100mg/kg/day 26.6kg child Max safe dose: 2660mg/day Min safe dose: 1330mg/day 100. ondasteron IV; up to 0.15mg/kg/day 26.6kg child Max safe dose: 3.99mg/day Min safe dose: None to be clarified. Can start at zero. 101. ORDER: Give 125mg IV Bactrim three times a day. You are working with a 125lb. child with chronic bronchitis. A drug reference book states that the safe range is 15-20mg/kg/day. Max safe dose: 1136.36 mg/day Min safe dose: 852.27 mg/day Total daily dose ordered: 375mg

99. Max: (26.6kg) x (100mg/kg/day) = 2660mg/day Min: (26.6kg) x (50mg/kg/day) = 1330mg/day

100. Max: (26.6kg) x (0.15mg/kg/day) = 3.99mg/day 101. First. Convert from lbs to kg. 125/2.2 = 56.8181 kg Second. Max: (56.818 kg) x (20 mg/kg/day) = 1136.36 mg/day Min: (56.818 kg) x (15 mg/kg/day) = 852.27 mg/day Third. (125 mg) x (3 doses) = 375 mg/day ordered

Is this dose safe? No – it is too little.

What would you do? Talk with ordering physician to have order corrected.


102. ORDER: Give 125mg amoxicillin PO four times a day. You are working with a 52 pound 12 ounce child with a systemic infection. A drug reference book states that the safe range is 20-40mg/kg/day. Max safe dose: 959.08 mg/day Min safe dose: 479.54 mg/day Total daily dose ordered: 500 mg/day

103. ORDER: Bactrim 0.25 g

IV over 30 min. STOCK: 500mg Bactrim in 50ml NS; 60gtt tubing What is the drip rate you will set? 50 gtts/min

102. First. Convert ounces to pounds: 12/16 = 0.75lbs Second. Convert from lbs to kg. 52.75/2.2 = 23.977 kg

Max: (23.977 kg) x (40 mg/kg/day) = 959.08 mg/day Min: (23.977 kg) x (20 mg/kg/day) = 479.54 mg/day Third (125mg) x (4 doses) = 500mg/day ordered

Is this dose safe? Yes – it is a safe dose. The ordered dose is more than the

minimum safe dose and less than the maximum safe dose. What would you do?

Administer the medication as ordered.

103. First. Remember the formula _V_ x DF = Drip Rate

T Second. Determine how much volume you will need to give Remember there are 1000mg in a gram so 0.25g = 250mg

Set up a proportion like this: 250mg = 500mg Xml 50 ml Third. Cross multiply to solve: (250mg) x (50ml) = (500mg) x (Xml) Fourth. (250mg) x (50ml) = 25 ml 500 mg

Fifth. Plug the numbers into the formula. 25 ml x 60gtt = 50 gtts/min

30min ml


104. ORDER: Vancomycin

150mg IV over 60 minutes

STOCK: 300mgVanco-mycin in 100ml of D5W

What will you set the pump at? 50ml/hour 105. ORDER: NS 50 ml IV over

30 minutes STOCK: NS 100ml; 60gtt

tubing What is the drip rate you will set? 100gtts/minute


T Second. Determine how much volume you will need to give Set up a proportion like this: 300mg = 150mg 100ml X Third. Cross multiply to solve: (300mg) x (X) = (100ml) x (150mg) Fourth. (100ml) x (150mg) = 50ml 300mg Fifth. Plug the numbers into the formula.

50 ml = 50ml/hour 1 hour 105. First. Remember the formula


Second. Plug the numbers into the formula 50ml x 60gtts = 100 gtts/minute 30 min ml


106. ORDER: Ancef 0.6g IV in 50mL D5NS over 20 min.

STOCK: Ancef 1gram in 100ml

What will you set the pump at?

107. ORDER: Cefobid

500mg IM every 6 hours STOCK: Vial that states, “Add 2 ml of dilutent to equal 2.4 ml of solution which contains 1 gram of cefobid.” How many ml will the nurse withdraw from the vial after it is reconstituted as indicated on the label?


T Second. Plug the numbers into the formula 50ml = Pump rate 20 min Third. This equals 2.5 ml/minute.

Fourth. REMEMBER – you aren’t done yet! Pump rate is usually set in ml/hour. So…you will need to convert like this:

Fifth. 2.5 ml x 60min = 150ml/hour min 1 hour 107. First. After the nurse adds 2 ml of dilutent to the vial the

concentration of the solution will be 1 gram / 2.4 ml. (This information is on the label)

Second. The order calls for 500 mg IM every 6 hours. Third. Convert mg to g to get 0.5 g Fourth.. Set up a proportion to solve for X like this:

1 gram = 0.5 g 2.4 ml X ml Fifth. Cross multiply and solve for X like this: (1 gram) x (X ml) = (2.4 ml) x (500 mg)

(2.4 ml) x (0.5 g) = Xml 1 gram 1.2 ml = X

ANSWER: The nurse withdraws 1.2 ml from the bottle. (This amount contains the ordered 500 mg of Cefobid.


108. ORDER: Oxacillin 500 mg IM every 6 hours STOCK: Vial that states, “Add 5.7 ml sterile water. each 1.5 ml contains 250mg oxacillin.” How many ml will the nurse administer after it is reconstituted as indicated on the label?

109. ORDER: Nafcillin sodium 250 mg IM every 6 hours STOCK: Vial that states, “Add 3.4 ml of sterile or bacteriostatic water. Each ml contains 1000mg of nafcillin. How many ml will the nurse withdraw from the vial after it is reconstituted as indicated on the label?

108. First. After the nurse adds 5.7 ml of sterile water to the vial the concentration of the solution will be 250

mg / 1.5 ml. (This information is on the label) Second. The order calls for 500 mg IM every 6 hours. Third. Set up a proportion to solve for X like this:

250 mg = 500 mg 1.5 ml X ml Fourth. Cross multiply and solve for X like this: (250 mg) x (X ml) = (1.5 ml) x (500 mg)

(1.5 ml) x (500 mg) = Xml 250 mg 3 ml = X

ANSWER: The nurse withdraws 3 ml from the bottle. (This amount contains the ordered 500 mg of Oxacillin.

109. First. After the nurse adds 3.4 ml of sterile or bacteriostatic water to the vial the concentration ` of the solution will be 1000mg of naficillin / ml Second. The order calls for 250mg of naficillin sodium Every 6 hours Third. Set up a proportion to solve for X like this: 1000 mg = 250mg 1 ml X ml Fourth. Cross multiply and solve for X like this: (1000 mg) x (X ml) = (1 ml) x (250 mg) (1 ml) x (250 mg) = X (1000 mg) ANSWER: 0.25 ml. The nurse withdraws 0.25 ml from the Bottle.(This amount contains the ordered 250 mg)


110. See right

(The underlined items are errors of ‘non-prefered’ abbreviations.)

110. O2 @ 2L/minute NC, 2.0mg MS IV, 3 SL .3mg nitroglycerine given

every 5 minutes, and an EKG was done. No relief within this first 15 minutes. Patient continued to complain of 9/10 substernal pain. IV nitroglycerine was started and titrated up to 200.00ug/min. Blood glucose was checked and result was 350.0, therefore 10U regular insulin was given SC in the left abdomen. Lasix 40mg PO QOD changed to 40.0 mg IV now….

70356097 dosage calculation

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