MedCalc_Training_presentation_0309.ppt

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Med-Math Calculations Med-Math Calculations for SJC Nursing for SJC Nursing

StudentsStudentsA Dimensional Analysis ApproachA Dimensional Analysis Approach

Variety of calculation typesVariety of calculation types Varying levels of difficultyVarying levels of difficulty Must (re)test every semester; usually 10-30 Must (re)test every semester; usually 10-30 calculations calculations Passing grade is defined as: ≥ 90%; no Passing grade is defined as: ≥ 90%; no partial creditpartial credit Prerequisite for giving medications in a Prerequisite for giving medications in a clinical settingclinical setting

B. Glick: 03/23/2009 @ 23:00B. Glick: 03/23/2009 @ 23:00Copyright 2009Copyright 2009

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Table of ContentsTable of Contents

Introductory Introductory text . . . . . . . . . . . . . . . . . . . . . . . . 1text . . . . . . . . . . . . . . . . . . . . . . . . 1

Problems solved in class . . . . . . . . . . . . . . . . . Problems solved in class . . . . . . . . . . . . . . . . . 1919

Easily solved problems (outside class). . . . . . Easily solved problems (outside class). . . . . . 6666

More solved problems (outside class). . . . . . More solved problems (outside class). . . . . . 6868

Answers to More solved problems . . . . . . . . Answers to More solved problems . . . . . . . . 93 93

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Why are you learning to Why are you learning to make these calculations?make these calculations?

It is physically impossible to stock every It is physically impossible to stock every medication in every possible dosage. medication in every possible dosage.

APRNs & physicians don’t know (or care) APRNs & physicians don’t know (or care) what is in your medication inventory.what is in your medication inventory.

Nurse must ACCURATELY do the Nurse must ACCURATELY do the arithmetic to use what is in the inventory arithmetic to use what is in the inventory and convert it to what the physician or and convert it to what the physician or APRN ordered.APRN ordered.

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The nurse’s most important The nurse’s most important role in medicating a patientrole in medicating a patient

The nurse is the patient’s last line of The nurse is the patient’s last line of defense against receiving an defense against receiving an inappropriate medication. inappropriate medication.

Right patient? Right medication? Right Right patient? Right medication? Right time?time?

Right route? Right dose? Right Right route? Right dose? Right form?form?

Expiration date?Expiration date?

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Arguments for/against Arguments for/against using dimensional analysisusing dimensional analysis

For:For: Formulas are derived from Formulas are derived from dimensional analysis. If you forget the dimensional analysis. If you forget the formula, you have no rational backup. formula, you have no rational backup. Guessing is not rational!Guessing is not rational!

For:For: By canceling the excess labels By canceling the excess labels before doing the arithmetic, the problem before doing the arithmetic, the problem setup is very likely to be correct. (Avoids setup is very likely to be correct. (Avoids the generation of an inappropriate or the generation of an inappropriate or nonsense answer such as: mLnonsense answer such as: mL22) )

Against:Against: Dimensional analysis is more Dimensional analysis is more work than using formulas.work than using formulas.

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Med-Math question types & Med-Math question types & sample units of measuresample units of measure

Intake/outputIntake/output Counting (tablets, units of medication)Counting (tablets, units of medication) Mass (weight)Mass (weight) Volume (mL, Liter)Volume (mL, Liter) Rate (drops/min, mL/hr, mg/min, units/hr)Rate (drops/min, mL/hr, mg/min, units/hr) Time-based (what time will the IV bag Time-based (what time will the IV bag

empty?)empty?) Reconstitution – Junior level nursing Reconstitution – Junior level nursing

studentsstudents IV rate changes - Junior level nursing IV rate changes - Junior level nursing

studentsstudents

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Time Abbreviations – Use of Time Abbreviations – Use of the “q” abbreviation is the “q” abbreviation is

discourageddiscouraged, but remains , but remains prevalent.prevalent.

q4h – every 4 hours q4h – every 4 hours q8h – every 8 hoursq8h – every 8 hours q12h – every 12 hours q12h – every 12 hours qd – every day (1 time/day)qd – every day (1 time/day) bid – every 12 hours (two times a day)bid – every 12 hours (two times a day) tid – every 8 hours (three times a day)tid – every 8 hours (three times a day)

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Other AbbreviationsOther Abbreviations Mass (weight): microgam (mcg)Mass (weight): microgam (mcg) milligram (mg) milligram (mg) gram (g)gram (g) kilogram (Kg) kilogram (Kg)

pounds (lbs, #)pounds (lbs, #)

Volume: milliliter (mL) = (cc) do not use Volume: milliliter (mL) = (cc) do not use “cc” “cc”

liter (L) liter (L) teaspoon (tteaspoon (tssp) ounce (oz)p) ounce (oz) tablespoon (tbs) cup (C)tablespoon (tbs) cup (C)

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Other Abbreviations -Other Abbreviations -continuedcontinued

Time: hour (h, hr) minute (min)Time: hour (h, hr) minute (min) Count: tablet (tab) Count: tablet (tab)

drop = gtt [Latin: gutta or guttae] drop = gtt [Latin: gutta or guttae]

(singular plural)(singular plural)

Unit [quantity of certain Unit [quantity of certain medications]medications]

mEq [milliequivalents for mEq [milliequivalents for electrolytes]electrolytes]

tablet tablet

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Rate definitionRate definition

Rate = flow Rate = flow (These two words mean the same thing)(These two words mean the same thing)

How much medication How much medication ANDAND how how quickly?quickly? VVolume & Time (gtt/min, mL/hr) olume & Time (gtt/min, mL/hr) MMass & Time (mg/min) ass & Time (mg/min) CCounting & Time (tablets/dose, Units/hr)ounting & Time (tablets/dose, Units/hr)

mL/hr is the default flow for IV mL/hr is the default flow for IV pumpspumps

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Graphic representation of Graphic representation of grams, milligrams and grams, milligrams and

microgramsmicrograms

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Introduction to problem Introduction to problem solvingsolving

Answer exactly Answer exactly what you are being asked what you are being asked to findto find.. Not what you think the question means.Not what you think the question means. Not what you think the question should ask.Not what you think the question should ask.

Determine the label for the answer.Determine the label for the answer.NOTE: The answer label should be, but NOTE: The answer label should be, but may notmay not

always be explicitly stated in the problem.always be explicitly stated in the problem.

Example: IV flow through a pump implies mL/hr.Example: IV flow through a pump implies mL/hr.

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Problem solving strategyProblem solving strategy

(1) Based upon the question, determine what (1) Based upon the question, determine what the answer’s label will be and place it to the answer’s label will be and place it to the right of the previous lines. Then place the right of the previous lines. Then place an equal sign (=) to the right of the label.an equal sign (=) to the right of the label.

(2) The numerator of term immediately to (2) The numerator of term immediately to the right of the answer’s numerator label the right of the answer’s numerator label mustmust match the answer’s numerator match the answer’s numerator label. You label. You maymay require a conversion require a conversion factor such as (1,000 mcg/1 mg) to force factor such as (1,000 mcg/1 mg) to force the correct label in the 1the correct label in the 1stst numerator. numerator.

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Problem solving strategyProblem solving strategy

(3) If the question asks you to find (for (3) If the question asks you to find (for example) mL/hr, set up the following example) mL/hr, set up the following generic statement. The intention is to generic statement. The intention is to cascade as many labels as you need so cascade as many labels as you need so that the labels that do not appear in the that the labels that do not appear in the answer are arithmetically canceled. (x to answer are arithmetically canceled. (x to x, y to y and z to z; leaving mL per hr, as x, y to y and z to z; leaving mL per hr, as required in the answer)required in the answer)

mLmL = = mLmL * * x x * * y y * * z z

hrhr x y z x y z hrhr

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Problem solving strategyProblem solving strategy Include medication order, medication source and Include medication order, medication source and

other factors to cancel labels that are not used in other factors to cancel labels that are not used in the answer. (examples that the answer. (examples that maymay be relevant: be relevant: patient weight, drip set ratio, time factors and patient weight, drip set ratio, time factors and conversions)conversions)

Notice that all parts of the formula containNotice that all parts of the formula contain

PAIRS of dataPAIRS of data. . Examples: gtt/mL, mg/hr, Examples: gtt/mL, mg/hr, mg/mL, g/L, “something”/dose, mgmg/mL, g/L, “something”/dose, mg//Kg/dayKg/day

By definition: a microdrip set = 60 ggt/mLBy definition: a microdrip set = 60 ggt/mL By definition: a macrodrip set = 10, 15 or 20 By definition: a macrodrip set = 10, 15 or 20

gtt/mLgtt/mL

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Rounding Rules. Always Rounding Rules. Always follow special directions in follow special directions in

the question.the question. Verify the rounding rules with your instructor. Typical rules Verify the rounding rules with your instructor. Typical rules

followfollow::

Infant & Pediatric: calculate Infant & Pediatric: calculate finalfinal answer to 3 places to right of answer to 3 places to right of decimal; then round back to 2 places. Follow the 5/4 rule: Value on decimal; then round back to 2 places. Follow the 5/4 rule: Value on dashed line affects solid lines.dashed line affects solid lines.

_______ . ___ ___ _______ . ___ ___ --------

Adult: calculate Adult: calculate finalfinal answer to 2 places to right of decimal; then answer to 2 places to right of decimal; then round back to 1 place. Follow the 5/4 rule: Value on dashed line round back to 1 place. Follow the 5/4 rule: Value on dashed line affects solid lines.affects solid lines.

_______ . __________ . ___ --------

Drops (gtt) and Units [medication] are always rounded to the Drops (gtt) and Units [medication] are always rounded to the nearest nearest whole numberwhole number. Follow the 5/4 rule: Value on dashed line affects solid . Follow the 5/4 rule: Value on dashed line affects solid lines.lines.

______________ . . --------

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Problem with an explicit Problem with an explicit answeranswer

Order: 400 mg of med. Supply: 125 mg per 5 mL.Order: 400 mg of med. Supply: 125 mg per 5 mL.

How many mL will you give? How many mL will you give?

5 mL * 400 mg5 mL * 400 mg

? mL = ------ ---------? mL = ------ ---------

125 mg 1 125 mg 1 an number over “1” makes an number over “1” makes thethe

numerator obvious & does numerator obvious & does notnot

= 16 mL change the numerator’s = 16 mL change the numerator’s value.value.

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Problem with an implied Problem with an implied answeranswer

Order: 400 mg of med. Supply: 125 mg per Order: 400 mg of med. Supply: 125 mg per 5 mL.5 mL.

5 mL * 400 mg5 mL * 400 mg ? mL = -------- ---------? mL = -------- --------- 125 mg 1125 mg 1 = 16 mL= 16 mL

All further examples are typed on these slides All further examples are typed on these slides as follows:as follows:

mL = (5 mL/125 mg) * (400 mg/1)mL = (5 mL/125 mg) * (400 mg/1) = 16 mL= 16 mL

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Class Problem mg/minClass Problem mg/min

Determine the Determine the mg/minmg/min required to required to administer when the flow and solution administer when the flow and solution concentration are given. The medication concentration are given. The medication is infusing at 32 mL/hr. The IV volume is is infusing at 32 mL/hr. The IV volume is 250 mL. The amount of dissolved 250 mL. The amount of dissolved medication is 700 mg. If necessary, medication is 700 mg. If necessary, round answer to 1 decimal place.round answer to 1 decimal place.

See next slide for important See next slide for important considerations.considerations.

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Class Problem mg/minClass Problem mg/min

Identify the Identify the pairspairs of data: 250 mL & 700 of data: 250 mL & 700 mgmg

1 hour and 32 1 hour and 32 mLmL

Orient the pairs as required to satisfy the Orient the pairs as required to satisfy the answer’s label and cancel all other labels.answer’s label and cancel all other labels.

Which conversion “tool” will you use to Which conversion “tool” will you use to change the hours to minutes?change the hours to minutes?

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Answer - mg/minAnswer - mg/min

Determine the Determine the mg/minmg/min required to administer when required to administer when the flow and solution concentration are given. The the flow and solution concentration are given. The medication is infusing at 32 mL/hr. The IV volume is medication is infusing at 32 mL/hr. The IV volume is 250 mL. The amount of dissolved medication is 700 250 mL. The amount of dissolved medication is 700 mg. mg.

mg/min=(700mg/250mL) * (32mL/hr) * (1 mg/min=(700mg/250mL) * (32mL/hr) * (1 hr/60min)hr/60min)

= 1.49 Round up to 1.5 mg/min= 1.49 Round up to 1.5 mg/min

______11____ . _____ . _44____ ----99--- - mg/min rounds to:mg/min rounds to:

______11____ . _____ . _5__5__ - - mg/min mg/min

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Class Problem – mcg/minClass Problem – mcg/min

Determine how many Determine how many mcg/minmcg/min are infusing are infusing if the IV contains 240 mg of medication per if the IV contains 240 mg of medication per 500 mL and is infusing at 16 mL/hr. If 500 mL and is infusing at 16 mL/hr. If necessary, round answer to 1 decimal place.necessary, round answer to 1 decimal place.

This problem does not have mcg in any of This problem does not have mcg in any of the data; therefore, put a conversion “tool’ the data; therefore, put a conversion “tool’ for mcg and mg immediately to the right of for mcg and mg immediately to the right of the equal sign (=). Then cascade and orient the equal sign (=). Then cascade and orient the rest of the data so that labels not the rest of the data so that labels not appearing in the answer’s label are canceled.appearing in the answer’s label are canceled.

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Answer – mcg/minAnswer – mcg/min

Determine how many Determine how many mcg/minmcg/min are are infusing if the IV contains 240 mg of infusing if the IV contains 240 mg of medication per 500 mL and is medication per 500 mL and is infusing at 16 mL/hrinfusing at 16 mL/hr

mcg/min = (1000mcg/mg) *(240mg/500mL) * (16mL/hr) mcg/min = (1000mcg/mg) *(240mg/500mL) * (16mL/hr) * (hr/60min)* (hr/60min)

= 218 mcg/min= 218 mcg/min

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Class Problem – mL/hrClass Problem – mL/hr

The provider has ordered 2 mcg/min. The provider has ordered 2 mcg/min. The nurse has 5 mg per 250 mL. The nurse has 5 mg per 250 mL. The flow rate is _________________ The flow rate is _________________ mL/hr. mL/hr. If necessary, round answer If necessary, round answer to 1 decimal place.to 1 decimal place.

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Answer – mL/hrAnswer – mL/hr

The provider has ordered 2 mcg/min. The provider has ordered 2 mcg/min. The nurse has 5 mg per 250 mL. The The nurse has 5 mg per 250 mL. The flow rate is _________________ flow rate is _________________ mL/hrmL/hr

mL/hr = (250mL/5mg) * (1 mg/1000mcg) * (2 mL/hr = (250mL/5mg) * (1 mg/1000mcg) * (2 mcg/min)* (60min/1 hr) mcg/min)* (60min/1 hr)

= 6 mL/hr= 6 mL/hr

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Class Problem – mL/hrClass Problem – mL/hr The provider ordered a medication at the rate of The provider ordered a medication at the rate of

46 mcg/Kg/min. The client weighs 72.7 Kg. The 46 mcg/Kg/min. The client weighs 72.7 Kg. The medication is supplied as 300 mg in 75 mL of medication is supplied as 300 mg in 75 mL of solution. The client should receive solution. The client should receive ____________________________mL/hr. mL/hr. If necessary, round answer If necessary, round answer to 1 decimal place.to 1 decimal place.

When using a 3-part component (e.g., When using a 3-part component (e.g., mcg/Kg/min), mcg/Kg/min),

always use the 1always use the 1stst component in the numerator (mg) component in the numerator (mg)and everything else in the denominator. For and everything else in the denominator. For

example:example: mg mg Kg/min Kg/min

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Answer – mL/hrAnswer – mL/hr

The provider ordered a medication at The provider ordered a medication at the rate of 46 mcg/Kg/min. The client the rate of 46 mcg/Kg/min. The client weighs 72.7 Kg. The medication is weighs 72.7 Kg. The medication is supplied as 300 mg in 75 mL of supplied as 300 mg in 75 mL of solution. The client should receive solution. The client should receive ____________________________mL/hrmL/hr

mL/hr = mL/hr =

(75mL/300mg) * (1 mg/1000mcg) * (46mcg/Kg/1 min) * (72.7 (75mL/300mg) * (1 mg/1000mcg) * (46mcg/Kg/1 min) * (72.7 Kg/1) * (60min/1 hr)Kg/1) * (60min/1 hr)

= 50.163 rounds up to 50.2 mL/hr= 50.163 rounds up to 50.2 mL/hr

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Class Problem - tabletsClass Problem - tablets

A medication comes out of the bottle A medication comes out of the bottle as 2.5mg/tablet. Give 2.5mg tid. If as 2.5mg/tablet. Give 2.5mg tid. If necessary, round answer to 1 necessary, round answer to 1 decimal place.decimal place.

(1) How many tablets/dose?(1) How many tablets/dose?

(2) How many tablets daily?(2) How many tablets daily?

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Answer - tabletsAnswer - tablets A medication comes out of the bottle as A medication comes out of the bottle as

2.5mg/tablets. 2.5mg/tablets. Give 2.5mg tid. Give 2.5mg tid.

(1) How many tablets/dose? (Each 1 dose = 2.5 (1) How many tablets/dose? (Each 1 dose = 2.5 mg.)mg.)

tabs/dose = (1 tab/2.5mg) * (2.5mg/1 dose) tabs/dose = (1 tab/2.5mg) * (2.5mg/1 dose) = 1 tablet/dose= 1 tablet/dose

(2) How many tablets daily? (tid = 3 doses/day)(2) How many tablets daily? (tid = 3 doses/day)

tabs/day = (1 tab/2.5mg) * (2.5mg/dose) * tabs/day = (1 tab/2.5mg) * (2.5mg/dose) * (3doses/day)(3doses/day)

= 3 tablet/day= 3 tablet/day

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Class Problem – mg/dayClass Problem – mg/day

The provider ordered 2 mg/Kg/day IV The provider ordered 2 mg/Kg/day IV for a 16 pound infant. The infant for a 16 pound infant. The infant should receive _____________should receive _____________mg per mg per dayday. If necessary, round answer to . If necessary, round answer to 2 decimal places.2 decimal places.

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Answer – mg/dayAnswer – mg/day

The provider ordered 2 mg/Kg/day IV The provider ordered 2 mg/Kg/day IV for a 16 pound infant. The infant for a 16 pound infant. The infant should receive _____________should receive _____________mg per mg per dayday..

mg/day = (2mg/Kg/day) * (1 Kg/2.2 lbs) * mg/day = (2mg/Kg/day) * (1 Kg/2.2 lbs) * (16 lbs/1)(16 lbs/1)

=14.545 round up to 14.55 =14.545 round up to 14.55 mg/daymg/day

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Class Problem – determine Class Problem – determine the label and solve the the label and solve the

problemproblem

A medication is ordered for your A medication is ordered for your patient at 80 mg/Kg/24 hours every patient at 80 mg/Kg/24 hours every 8 hours. The child weighs 18 lbs. 8 hours. The child weighs 18 lbs. How many mg of medication will you How many mg of medication will you administer at each dose? If administer at each dose? If necessary, round answer to 1 necessary, round answer to 1 decimal place.decimal place.

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Answer – determine the Answer – determine the label and solve the problemlabel and solve the problem

A medication is ordered for your A medication is ordered for your patient at 80 mg/Kg/24 hours every 8 patient at 80 mg/Kg/24 hours every 8 hours. The child weighs 18 lbs. How hours. The child weighs 18 lbs. How many mg of medication will you many mg of medication will you administer at each dose? administer at each dose?

mg/dose= (80mg/Kg/24hrs) * (8hrs/dose) * (1 Kg/2.2 lbs) mg/dose= (80mg/Kg/24hrs) * (8hrs/dose) * (1 Kg/2.2 lbs) * (18 lbs/1)* (18 lbs/1)

= 218.182 rounds down to 218.2 mg/dose= 218.182 rounds down to 218.2 mg/dose

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Class Problem – gtt/minClass Problem – gtt/min

Calculate the drip rate of 1,000 mL Calculate the drip rate of 1,000 mL of medication to infuse over 10 of medication to infuse over 10 hours using an infusion set that hours using an infusion set that delivers 15gtt/mL. How many delivers 15gtt/mL. How many drops/min? If necessary, round drops/min? If necessary, round answer to 1 decimal place.answer to 1 decimal place.

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Answer – gtt/minAnswer – gtt/min

Calculate the drip rate of 1,000 mL Calculate the drip rate of 1,000 mL of medication to infuse over 10 of medication to infuse over 10 hours using an infusion set that hours using an infusion set that delivers 15gtt/mL.delivers 15gtt/mL.

gtt/min= (15gtt/mL) * (1,000 mL/10 hrs) * (1 gtt/min= (15gtt/mL) * (1,000 mL/10 hrs) * (1 hr/60 min) hr/60 min)

= 25gtt/min= 25gtt/min

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4 AM4 AM

5 AM5 AM

6 AM6 AM

7 AM7 AM

8 AM8 AM

9 AM9 AM

10 AM10 AM

To the patient

1,000 mL

900 mL

800 mL

700 mL

600 mL

500 mL

400 mL

0 mL

Expectation What is observed

1,000 mL

? mL

? mL

? mL

? mL

? mL

600 mL

1 Liter bag of

medication

Drip chamber 7 tubing

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Class Problem – Is the IV Class Problem – Is the IV setup working as expected?setup working as expected?

The IV above was started at 4 AM. The IV above was started at 4 AM. At 10 AM 600 mL remain in the At 10 AM 600 mL remain in the

bottle. bottle. Is the IV running on time? Is the IV running on time?

(Refer to previous slide for (Refer to previous slide for mL/hr)mL/hr)

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Answer – Is the IV setup Answer – Is the IV setup working as expected?working as expected?

The IV above was started at 4 AM. The IV above was started at 4 AM. At 10 AM 600 mL remain in the bottle. At 10 AM 600 mL remain in the bottle. Is the IV running on time?Is the IV running on time?

(4 AM to 10 AM) = 6 hrs running time.(4 AM to 10 AM) = 6 hrs running time. (1,000 mL/10 hrs) = 100 mL/hr.(1,000 mL/10 hrs) = 100 mL/hr. (100 mL/hr * 6 hrs/1) = 600 mL should be used in 6 hours.(100 mL/hr * 6 hrs/1) = 600 mL should be used in 6 hours. (1,000 mL – 600 mL) = 400 mL should still be in the bottle.(1,000 mL – 600 mL) = 400 mL should still be in the bottle. Therefore: bottle is emptying too slowly – NO: not on time.Therefore: bottle is emptying too slowly – NO: not on time. Patient Patient maymay have laid on the tubing and caused it to crimp. have laid on the tubing and caused it to crimp.

There are other possible reasons for the delayed There are other possible reasons for the delayed emptying.emptying.

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Conversion factors to Conversion factors to memorizememorize

1 oz = 30 mL1 oz = 30 mL 8 oz = 1 cup = 240 mL8 oz = 1 cup = 240 mL ============================================ 16 oz = 1 pint = 500 mL16 oz = 1 pint = 500 mL 32 oz = 1 quart = 1,000 mL = 32 oz = 1 quart = 1,000 mL =

1 liter1 liter 128 oz = 1 gallon = 4,000 mL128 oz = 1 gallon = 4,000 mL

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Class Problem – Intake & Class Problem – Intake & OutputOutput

12 hour I/O for patient Smith on 4/7/200812 hour I/O for patient Smith on 4/7/2008:: 4 oz cranberry juice 175 mL urine 1/2 cup 4 oz cranberry juice 175 mL urine 1/2 cup

oatmeal 2 slices of toast 120 mL oatmeal 2 slices of toast 120 mL yellow vomit 8 oz black coffee yellow vomit 8 oz black coffee

a tuna fish sandwich 1/2 cup flavored gelatin 100 mL a tuna fish sandwich 1/2 cup flavored gelatin 100 mL diarrhea 3 oz cream of mushroom soup 6 oz 1% milk diarrhea 3 oz cream of mushroom soup 6 oz 1% milk 230 mL urine 230 mL urine

16 oz water 1 pint ice cream 16 oz water 1 pint ice cream 2 tsp liquid medication 1 tbs liquid medication 2 tsp liquid medication 1 tbs liquid medication IV @ 150mL for 3 hrs 1 cup applesauceIV @ 150mL for 3 hrs 1 cup applesauce

What is the intake? ______________What is the intake? ______________What is the output? ______________What is the output? ______________Net gain or net loss of fluid? Net gain or net loss of fluid?

______________

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Answer - IntakeAnswer - Intake4 oz cranberry juice4 oz cranberry juice 4 oz * 30 mL/oz = 120 mL 4 oz * 30 mL/oz = 120 mL

8 oz black coffee 8 oz black coffee 8 oz * 30 mL/oz = 240 mL8 oz * 30 mL/oz = 240 mL1/2 cup flavored gelatin 1/2 cup flavored gelatin 4 oz * 30 mL/oz = 120 mL4 oz * 30 mL/oz = 120 mL3 oz cream of mushroom soup3 oz cream of mushroom soup 3 oz * 30 mL/oz = 90 mL3 oz * 30 mL/oz = 90 mL6 oz 1% milk6 oz 1% milk 6 oz * 30 mL/oz = 180 mL6 oz * 30 mL/oz = 180 mL16 oz water16 oz water 1 pint1 pint = 500 mL = 500 mL1 pint ice cream 1 pint ice cream 1 pint 1 pint = 500 = 500

mLmL2 tsp liquid medication 2 tsp liquid medication 2 tsp * 5 mL/tsp = 10 mL2 tsp * 5 mL/tsp = 10 mL1 tbs liquid medication 1 tbs liquid medication 1 tbs * 15 mL/tbs = 15 mL1 tbs * 15 mL/tbs = 15 mLIV @ 150 mL for 3 hrs IV @ 150 mL for 3 hrs 150 mL/hr * 3 hr = 450 mL150 mL/hr * 3 hr = 450 mL1 cup applesauce1 cup applesauce 1 cup * 16 oz/cup = 240 mL1 cup * 16 oz/cup = 240 mL Answer: - ----------------------------------------Answer: - ---------------------------------------- 2,465 mL 2,465 mL

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Answer - Output & Net Answer - Output & Net gain or lossgain or loss

175 mL urine175 mL urine

120 mL yellow vomit120 mL yellow vomit

230 mL urine230 mL urine

100 mL diarrhea100 mL diarrhea Input = 2,465 mL Input = 2,465 mL

625 mL Output 625 mL Output Output = 625 mLOutput = 625 mL

Net Net gaingain = 1,840 mL = 1,840 mL

More fluid was retainedMore fluid was retained

than was excreted; than was excreted; therefore,therefore,

patient has a net gain. patient has a net gain.

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Class Problem mL/hrClass Problem mL/hr with distracters with distracters

This problem contains distracters. Determine This problem contains distracters. Determine what the answer label is. Then look to see what the answer label is. Then look to see which components of the question will satisfy which components of the question will satisfy the requirements for the answer’s label. the requirements for the answer’s label. Ignore everything else. If necessary, round Ignore everything else. If necessary, round answer to 1 decimal place. answer to 1 decimal place.

An IV of 1,000 mL medication contains 60 An IV of 1,000 mL medication contains 60 mEq of an electrolyte and is set to infuse at mEq of an electrolyte and is set to infuse at 27 drops per minute. The tubing delivers 27 drops per minute. The tubing delivers 10gtts/cc. How many mL/hr are you 10gtts/cc. How many mL/hr are you administering? administering?

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Answer - mL/hr Answer - mL/hr with distracterswith distracters

An IV of 1,000mL medication contains 60 mEq of an electrolyte An IV of 1,000mL medication contains 60 mEq of an electrolyte and is set to infuse at 27 drops per minute. The tubing and is set to infuse at 27 drops per minute. The tubing delivers 10gtts/cc. How many mL/hr are you administering? delivers 10gtts/cc. How many mL/hr are you administering?

Be in the habit of rewriting drops to gtt and cc to mL. Be in the habit of rewriting drops to gtt and cc to mL. Remember to find Remember to find pairspairs of data that of data that maymay work for you. work for you. 27 gtt/min 10 gtt/mL mL/hr 1,000 mL/mEq27 gtt/min 10 gtt/mL mL/hr 1,000 mL/mEq

Correct answer: mL/hr = (1 ml/10 gtt) * (27 gtt/1 min) Correct answer: mL/hr = (1 ml/10 gtt) * (27 gtt/1 min) * (60 min/1 hr)* (60 min/1 hr)

= 162mL/hr= 162mL/hr

Why is this wrong? Why is this wrong? mL/hr = (1,000 ml/60 mEq) *mL/hr = (1,000 ml/60 mEq) * (27 gtt/1 min) * (60 min/1 (27 gtt/1 min) * (60 min/1

hr)hr)

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Class Problem – Time-basedClass Problem – Time-based Unless otherwise specified, and if Unless otherwise specified, and if

necessary, round answer to 1 decimal necessary, round answer to 1 decimal place.place.

900 mL of medication is ordered to infuse 900 mL of medication is ordered to infuse at 80 mL per hour. at 80 mL per hour.

(1) Assuming that there are no (1) Assuming that there are no interruptions, how long will it take to interruptions, how long will it take to empty the bag?empty the bag?

(2) If the IV line is started at 2:47 PM, what (2) If the IV line is started at 2:47 PM, what time will the bag run dry?time will the bag run dry?

46

Answer - Calculate the Answer - Calculate the hourshours

1) Assuming that there are no interruptions, 1) Assuming that there are no interruptions, how long will it take to empty the bag?how long will it take to empty the bag?

Hours = (1 hr/80 mL) * ( 900 mL/1)Hours = (1 hr/80 mL) * ( 900 mL/1) = = 11.2511.25 hourshours This answer is expressed in hours and it This answer is expressed in hours and it

meansmeans 11 and ¼ hours.11 and ¼ hours.

It is NOT 11 hours and 25 minutes!It is NOT 11 hours and 25 minutes!

47

Answer - Calculate the Answer - Calculate the minutesminutes

minutes = (60 min/1 hr) * (0.25 minutes = (60 min/1 hr) * (0.25 hr/1)hr/1)

= 15 = 15 minutesminutes

48

Answer – total run time Answer – total run time expressed in hours & expressed in hours &

minutesminutes

(1) Assuming that there are no (1) Assuming that there are no interruptions, howinterruptions, how

long will it take to empty the bag?long will it take to empty the bag?

The bag will empty in 11 hours The bag will empty in 11 hours and 15 min. and 15 min.

49

Answer - Time bag will Answer - Time bag will theoretically emptytheoretically empty

(2) If the IV line is started at (2) If the IV line is started at 22::4747 PMPM, , what time will the bag run dry?what time will the bag run dry?

(from previous page)(from previous page)

22 PM + 11 hours -------> 1 AM PM + 11 hours -------> 1 AM 4747 minutes + 15 minutes = 62 minutes + 15 minutes = 62

minutesminutes 1 AM + 62 minutes ------> 1 AM + 62 minutes ------> 2:02 AM2:02 AM

50

Class Problem – Class Problem – ReconstitutionReconstitution

Reconstitution problems ask the nurse to Reconstitution problems ask the nurse to dissolve a drug (typically a powder) whose dissolve a drug (typically a powder) whose quantity is usually expressed in grams or quantity is usually expressed in grams or

milligrams milligrams inin::

a specific quantity of a liquid (usually a specific quantity of a liquid (usually measured in milliliters). Frequently, the measured in milliliters). Frequently, the liquid is normal saline (0.9% NS) or D5W.liquid is normal saline (0.9% NS) or D5W.

Conceptually, this is identical to dissolving Conceptually, this is identical to dissolving 1 teaspoon of table salt in 1 cup of hot 1 teaspoon of table salt in 1 cup of hot water.water.

51


Order: 350 mg of the drug to be given Order: 350 mg of the drug to be given q8h IV. How many q8h IV. How many mL will you give mL will you give per doseper dose??

Supply: The drug is available in 500 Supply: The drug is available in 500 mg containers. The label tells the mg containers. The label tells the nurse to dissolve the powder in 25 nurse to dissolve the powder in 25 mL of normal saline (NS).mL of normal saline (NS).

52


Which pairs of data do you find in the problem?Which pairs of data do you find in the problem? 350 mg every 8 hours. (every 8 hours means: 1 350 mg every 8 hours. (every 8 hours means: 1

dose.)dose.) 500 mg of the powder is dissolved in 25 mL of 500 mg of the powder is dissolved in 25 mL of

NS.NS.

What is the answer’s label for your calculation?What is the answer’s label for your calculation? How many mL/dose? How many mL/dose?

Can you isolate all of the components that are required Can you isolate all of the components that are required to solve this problem?to solve this problem? (YES, of course you can do (YES, of course you can do this!)this!)

53

Answer – ReconstitutionAnswer – Reconstitution

mL/dose = (25 mL/500 mg) * (350 mL/dose = (25 mL/500 mg) * (350 mg/dose)mg/dose)

= 17.5 mL/dose= 17.5 mL/dose

54


Order: 250 mg of the drug to be given Order: 250 mg of the drug to be given q8h IV. How many q8h IV. How many mL will you give per mL will you give per dosedose??

Supply: The drug is available in 1g Supply: The drug is available in 1g containers. The label tells the nurse to containers. The label tells the nurse to dissolve the powder in 50 mL of normal dissolve the powder in 50 mL of normal saline (NS).saline (NS).

The disconnect is between the grams and The disconnect is between the grams and the milligrams, so use the appropriate the milligrams, so use the appropriate conversion “tool.”conversion “tool.”

55


mL/dose = (50 mL/1 g) * (1 g/1000 mL/dose = (50 mL/1 g) * (1 g/1000 mg) *mg) *

(250 mg/dose)(250 mg/dose)

= 12.5 mL/dose= 12.5 mL/dose

56


Order: 20 mg/Kg of the drug to be given Order: 20 mg/Kg of the drug to be given q8h IV. Patient weighs 50 pounds. How q8h IV. Patient weighs 50 pounds. How many many mL will you give per dosemL will you give per dose??

Supply: The drug is available in 500 mg Supply: The drug is available in 500 mg containers. The label tells the nurse to containers. The label tells the nurse to dissolve the powder in 5 mL of normal dissolve the powder in 5 mL of normal saline (NS).saline (NS).

With which data pair is the “dose” a With which data pair is the “dose” a factor? Why?factor? Why?

57


mL/dose = (5 mL/500 mg) * (20 mg/1 mL/dose = (5 mL/500 mg) * (20 mg/1 Kg/1 dose) *Kg/1 dose) *

(1 Kg/2.2 lbs) * (50 lbs/1) (1 Kg/2.2 lbs) * (50 lbs/1)

= 4.545 rounds up to 4.55 = 4.545 rounds up to 4.55 mL/dosemL/dose

Dose is only related mg/Kg. Any Dose is only related mg/Kg. Any other pair does not make any sense.other pair does not make any sense.

58


Order: 700,000 Units given IM. How many Order: 700,000 Units given IM. How many mL mL will you givewill you give??

Supply: The drug is available in 5,000,000 Unit Supply: The drug is available in 5,000,000 Unit containers. The label tells the nurse to containers. The label tells the nurse to reconstitute (dissolve) the powder in 3.2 mL of reconstitute (dissolve) the powder in 3.2 mL of normal saline (NS) to yield 1,000,000 Units/mL.normal saline (NS) to yield 1,000,000 Units/mL.

This problem contains a distracting pair. To This problem contains a distracting pair. To determine what the distracting pair is, you determine what the distracting pair is, you must understand the sequence of the problem’s must understand the sequence of the problem’s operation. See picture on next slide.operation. See picture on next slide.

59

Reconstitution GraphicReconstitution Graphic

5 million Units in 3.2 mL

1 million Units/1 mL

The patient

Which medication source DIRECTLY affects the patient?

60


The distracters are the 5 million Units The distracters are the 5 million Units andand 3.2 mL. 3.2 mL.

Your reconstituted supply is now 1 million Your reconstituted supply is now 1 million Units/mL. Units/mL.

The 5 million units dissolved in the 3.2mL is The 5 million units dissolved in the 3.2mL is how you arrived at the 1 million Units/mL. how you arrived at the 1 million Units/mL. Now they are Now they are irrelevant irrelevant == distractors distractors..

mL = (1 mL/1,00,000 Units) * mL = (1 mL/1,00,000 Units) * (7.000,000 Units/1)(7.000,000 Units/1) = 0.7 mL= 0.7 mL

61


Order: 500 mg IV every 4 hours.Order: 500 mg IV every 4 hours.

Supply: The drug is available in 1 Supply: The drug is available in 1 gram containers. The label tells the gram containers. The label tells the nurse to reconstitute (dissolve) the nurse to reconstitute (dissolve) the powder in 10 mL of 0.9% NS. THEN powder in 10 mL of 0.9% NS. THEN further dilute this mixture in 50 mL further dilute this mixture in 50 mL of NS. Infuse it over 30 minutes. The of NS. Infuse it over 30 minutes. The drip set is 10gtt/mL. drip set is 10gtt/mL.

62


Refer to the previous graphic and make a Refer to the previous graphic and make a similar picture for this problem.similar picture for this problem.

Step-A: How many mL will you use of the 10 Step-A: How many mL will you use of the 10 mLmL

in which you dissolve the 500 mg of in which you dissolve the 500 mg of powder?powder?

Step-B: How many Step-B: How many mL/hrmL/hr will you give the will you give the patient?patient?

Step-C: How many Step-C: How many drops/mindrops/min??

63

Answer – ReconstitutionAnswer – ReconstitutionThis is a multi-step (3) problem.This is a multi-step (3) problem.

(A) Determine how many mL after (A) Determine how many mL after mixing the powder (Step-1).mixing the powder (Step-1).

mL = (10 mL/1 gram) * (1 mL = (10 mL/1 gram) * (1 gram/1,000 mg) *gram/1,000 mg) *

500 mg/1)500 mg/1)

= 5 mL= 5 mL

64


(B) Determine how many mL/hr after (B) Determine how many mL/hr after diluting the mixture (Step-2).diluting the mixture (Step-2).

mL/hr = (55 mL/30 min) * (60 min/1 mL/hr = (55 mL/30 min) * (60 min/1 hr) hr)

= 110 mL/hr= 110 mL/hr

Your picture should tell you why we use Your picture should tell you why we use 55 mL, not 50 mL.55 mL, not 50 mL.

65


(C) Determine how many gtt/min:(C) Determine how many gtt/min:

gtt/min = (10 gtt/1 mL) * (110 mL/1 gtt/min = (10 gtt/1 mL) * (110 mL/1 hr) *hr) *

(1 hr/60 min)(1 hr/60 min)

= 18.3 rounds down to 18 = 18.3 rounds down to 18 gtt/mingtt/min

66

Easily solved problemsEasily solved problemswith answers with answers – [in brackets]– [in brackets]

Supply: 5 mg/mL. Order: 50 mg. Tsp____? Supply: 5 mg/mL. Order: 50 mg. Tsp____? [2 tsp][2 tsp]

Supply: 10 mg tablets. Order: 30 mg. Tablets__? Supply: 10 mg tablets. Order: 30 mg. Tablets__? [3 [3 tablets]tablets]

Supply: 250 mg/5 mL. Order: 1.5 g. mL____? Supply: 250 mg/5 mL. Order: 1.5 g. mL____? [30 [30 mL]mL]

Supply: 50 mg tablets. Order: 0.2 g. Tablets__? Supply: 50 mg tablets. Order: 0.2 g. Tablets__? [4 [4 tablets]tablets]

Supply: 100 mg/5mL. Order: 0.25 g. mL____? Supply: 100 mg/5mL. Order: 0.25 g. mL____? [12.5 [12.5 mL]mL]

Supply: 5 mL/tsp, tsp contains 250 mg.Supply: 5 mL/tsp, tsp contains 250 mg.Order: 0.5 g . mL____? [10 mL]Order: 0.5 g . mL____? [10 mL]

67

Easily solved problemsEasily solved problemswith answerswith answers

Supply: 10 mL/1 million Units. Supply: 10 mL/1 million Units. Order: 200,000 Units. mL____? [2 mL]Order: 200,000 Units. mL____? [2 mL]

Supply: each tablet contains 0.25 g. Supply: each tablet contains 0.25 g. Order: 500 mg. Tabs___? [2 Order: 500 mg. Tabs___? [2

tablets]tablets]

Supply: 2 mL per 600,000 Units. Supply: 2 mL per 600,000 Units. Order: 300,000 Units. mL____? [1 mL]Order: 300,000 Units. mL____? [1 mL]

Supply: 0.1 g per tablet. Supply: 0.1 g per tablet. Order: 200 mg. Tabs____? [2 tablets]Order: 200 mg. Tabs____? [2 tablets]

Supply: 500 mcg in 1.5 mL. Supply: 500 mcg in 1.5 mL. Order: 0.8 mg. mL____? [2.4 mL]Order: 0.8 mg. mL____? [2.4 mL]

68

More Solved Problems More Solved Problems – Unless – Unless otherwise instructed, as necessary, round all otherwise instructed, as necessary, round all

final answers to 1 decimal place.final answers to 1 decimal place.

How many How many millilitersmilliliters you will give you will give for each medication? Answers for each medication? Answers begin on slide 92.begin on slide 92.

1. Give your patient 0.1 mcg. Your 1. Give your patient 0.1 mcg. Your stock has 1.5 mL vials with 0.3 mcg.stock has 1.5 mL vials with 0.3 mcg.

2. Order is for 3,500 Units. Supply is 2. Order is for 3,500 Units. Supply is 8,500 Units per 1.5 mL.8,500 Units per 1.5 mL.

69

More Solved ProblemsMore Solved Problems

3. Prepare a 25 mEq dose. You have 20 3. Prepare a 25 mEq dose. You have 20 mEq dissolved in 10 mL.mEq dissolved in 10 mL.

4. Supply is 1 mg/mL. You are ordered 4. Supply is 1 mg/mL. You are ordered to give 750 mcg.to give 750 mcg.

5. Your inventory contains a bottle with 5. Your inventory contains a bottle with 0.4 g in 2 mL. Order is for 300 mg.0.4 g in 2 mL. Order is for 300 mg.

70


6. Supply is an elixor labeled 3 mg/mL. 6. Supply is an elixor labeled 3 mg/mL. Order is for 3 teaspoons. How many Order is for 3 teaspoons. How many milliliters will you give? This dose is milliliters will you give? This dose is equal to how many milligrams?equal to how many milligrams?

7. The order is for an oral suspension of 7. The order is for an oral suspension of 50 mg. your inventory contains 25 50 mg. your inventory contains 25 mg/5 mL. How many teaspoons will mg/5 mL. How many teaspoons will you give?you give?

71


8. Drug comes in 10 mg tablets. APRN 8. Drug comes in 10 mg tablets. APRN orders 30 mg daily. How many tablets orders 30 mg daily. How many tablets will you give over the course of the will you give over the course of the whole day? How many tabs per dose if whole day? How many tabs per dose if the drug is to be given every 8 hours the drug is to be given every 8 hours (tid)?(tid)?

9. Prescribed are 1.5 mg. Liquid is labeled 9. Prescribed are 1.5 mg. Liquid is labeled 250 mg per 5 mL. How many mL will you 250 mg per 5 mL. How many mL will you give?give?

72


10. Give your patient 200,000 Units. 10. Give your patient 200,000 Units. Available is a multiple dose vial Available is a multiple dose vial labeled 1,000,000 Units in 10 mL labeled 1,000,000 Units in 10 mL (cc). How many mL will you give?(cc). How many mL will you give?

11. You have scored (can be split) 11. You have scored (can be split) tablets labeled 0.1 g. Your order is tablets labeled 0.1 g. Your order is for 200 mg every morning. How for 200 mg every morning. How many tablets, or part of a tablet, will many tablets, or part of a tablet, will you give?you give?

73


12. Prescribed is a 0.75 mg dose for an 12. Prescribed is a 0.75 mg dose for an infant weighing 8.7 pounds. The drug infant weighing 8.7 pounds. The drug is available as 500 mcg dissolved in is available as 500 mcg dissolved in 1.5 mL. How many mL will you give?1.5 mL. How many mL will you give?

13. 360 mg to be given orally every 4 13. 360 mg to be given orally every 4 to 6 hours. Available drug is 180 to 6 hours. Available drug is 180 mg/5 mL. How many mL should be mg/5 mL. How many mL should be given at each dose?given at each dose?

74


14. Your patient weighs 60 Kg. Order is 14. Your patient weighs 60 Kg. Order is for 500 mg of medication daily. Drug for 500 mg of medication daily. Drug package instructions say there are 125 package instructions say there are 125 mg/tsp. How many milliliters will you mg/tsp. How many milliliters will you give?give?

15. Patient weighs 41 pounds. APRN 15. Patient weighs 41 pounds. APRN orders 75 mg/Kg/day in 4 divided doses. orders 75 mg/Kg/day in 4 divided doses. Drug is available in 175 mg/3 mL. How Drug is available in 175 mg/3 mL. How many mL should be give for many mL should be give for eacheach dose? dose?

75


16. Give 15 mg/Kg/day. Drug is prescribed 16. Give 15 mg/Kg/day. Drug is prescribed in 3 evenly spaced doses over 24 hours. in 3 evenly spaced doses over 24 hours. Patient weighs 231 pounds. Patient weighs 231 pounds.

(A) How many hours apart will you give (A) How many hours apart will you give each dose? each dose?

(B) If the drug is available in units of (B) If the drug is available in units of 75mg/mL, how many milliliters will you 75mg/mL, how many milliliters will you give per dose?give per dose?

76


17. How many micrograms are in 1 17. How many micrograms are in 1 gram?gram?

18. How many mL in 4 tablespoons?18. How many mL in 4 tablespoons?

19. Give 500 mL of an IV liquid over 8 19. Give 500 mL of an IV liquid over 8 hours. The drip set is 10 drops/mL. hours. The drip set is 10 drops/mL. How many gtt/min will you adjust How many gtt/min will you adjust the manual control on the drip set?the manual control on the drip set?

77


20. A piggyback IV liquid contains 50 mL 20. A piggyback IV liquid contains 50 mL of medication. It is attached to a of medication. It is attached to a microdrip set. Deliver the medication microdrip set. Deliver the medication over 2 hours. How many drops per over 2 hours. How many drops per minute is this?minute is this?

21. Referring to the previous problem, 21. Referring to the previous problem, what happens to the flow of medication what happens to the flow of medication from the main medication bag when the from the main medication bag when the piggyback is running thru the IV line?piggyback is running thru the IV line?

78


22. An IV drug is administered via a pump. 22. An IV drug is administered via a pump. The medication is packaged as 50 mg per The medication is packaged as 50 mg per 100 mL of liquid to be given over 2 hours. 100 mL of liquid to be given over 2 hours. The drip set package is marked 15 gtt. The drip set package is marked 15 gtt. How many mL/hour will you set the How many mL/hour will you set the pump?pump?

23. Using a pump, an IV medication is to be 23. Using a pump, an IV medication is to be given over 90 minutes. The medication is given over 90 minutes. The medication is dispensed from a 250 milliliter bag. How dispensed from a 250 milliliter bag. How many mL/hour will you set the pump?many mL/hour will you set the pump?

79


24. Order is for 16 mcg/Kg. Infuse in 24. Order is for 16 mcg/Kg. Infuse in 90 minutes. Drug volume is 75 mL. 90 minutes. Drug volume is 75 mL. The patient is a child who weighs 46 The patient is a child who weighs 46 pounds. The child should receive pounds. The child should receive 223.03 mcg at a rate of ____ 223.03 mcg at a rate of ____ mL/hour?mL/hour?

80


25. 150 mL of liquid contains 8 mEq of 25. 150 mL of liquid contains 8 mEq of a continuous infusion at 25 ml/hour. a continuous infusion at 25 ml/hour. The patient will receive how many The patient will receive how many mEq/day?mEq/day?

26. How many mcg/min are being 26. How many mcg/min are being infused if an IV contains 150 mg of infused if an IV contains 150 mg of medication per 250 mL and is medication per 250 mL and is infusing at 10 mL/hr? infusing at 10 mL/hr?

81

More Solved ProblemsMore Solved Problems27. Calculate the intake expressed in mL and in liters. Ignore 27. Calculate the intake expressed in mL and in liters. Ignore

the output.the output.

6 oz orange juice 6 oz orange juice 150 mL urine150 mL urine2/3 cup cereal with an additional 4 oz whole milk2/3 cup cereal with an additional 4 oz whole milk3 pancakes covered with 1 oz maple syrup3 pancakes covered with 1 oz maple syrup120 mL of brownish-yellow vomit120 mL of brownish-yellow vomit6 oz black coffee with an additional 2 oz 2% milk6 oz black coffee with an additional 2 oz 2% milk1/4 cup orange gelatin1/4 cup orange gelatin100 mL diarrhea100 mL diarrhea3 tbs apple sauce3 tbs apple sauceAn IV infusing at 150 mL/hr for 8 hoursAn IV infusing at 150 mL/hr for 8 hours2 tsp liquid medicine2 tsp liquid medicine2 pills taken with a total of 4 oz water2 pills taken with a total of 4 oz water1 pint sherbet1 pint sherbet

82


28. 450 mL of medication is ordered to infuse 28. 450 mL of medication is ordered to infuse atat

52 mL per hour. 52 mL per hour.

(A) Assuming that there are no interruptions,(A) Assuming that there are no interruptions, how long will it take to empty the bag?how long will it take to empty the bag?

(B) If the IV line is started at 7:47 PM, what(B) If the IV line is started at 7:47 PM, what time will the bag run dry?time will the bag run dry?

83


29. A dehydrated patient is placed on a 29. A dehydrated patient is placed on a continuous drip at 15mL/hr. The drip set is continuous drip at 15mL/hr. The drip set is 15 gtt/mL. The nurse enters the patient’s 15 gtt/mL. The nurse enters the patient’s bathroom where she observes a toilet bathroom where she observes a toilet mounted hat containing 200 ml of urine. An mounted hat containing 200 ml of urine. An unlicensed assistant tells the nurse that unlicensed assistant tells the nurse that within the past few minutes he cleaned up 2 within the past few minutes he cleaned up 2 times after the patient soiled himself and times after the patient soiled himself and the bed. Each time about 75 mL of diarrhea the bed. Each time about 75 mL of diarrhea came out. Then the patient vomited about came out. Then the patient vomited about 250 mL. 250 mL.

84


(A) How much fluid was lost?(A) How much fluid was lost?

(B) The physician orders the existing (B) The physician orders the existing drip to continue as ordered PLUS an drip to continue as ordered PLUS an order to replace the lost fluid over order to replace the lost fluid over the next hour. How much fluid will the next hour. How much fluid will the nurse infuse over the next hour?the nurse infuse over the next hour?

(C) How many drops/minute?(C) How many drops/minute?

85


(D) In a separate IV, the patient is (D) In a separate IV, the patient is receiving 1350 Units/hr of a receiving 1350 Units/hr of a medication that is dispensed from a medication that is dispensed from a 500 mL bag containing 25,000 Units 500 mL bag containing 25,000 Units of the drug through a of the drug through a micromicro drip set. drip set. How many mL/hr are being infused?How many mL/hr are being infused?

(E) How many drops/minute are being (E) How many drops/minute are being infused?infused?

86


The physician decides to increase the The physician decides to increase the dosage by 3 Units/Kg/hr. The patient dosage by 3 Units/Kg/hr. The patient weighs 185 pounds.weighs 185 pounds.

(F) How many Units/hr will the nurse (F) How many Units/hr will the nurse administer?administer?

(G) How many mL/hour will the pump (G) How many mL/hour will the pump be set?be set?

87


(H) How many gtt/min will be (H) How many gtt/min will be infused?infused?

(I) How many hours will this IV run? (I) How many hours will this IV run? Express as a decimal quantity – 3 Express as a decimal quantity – 3 decimal places?decimal places?

88


(J) How many whole hours will the IV (J) How many whole hours will the IV run?run?

(K) How many remaining minutes will (K) How many remaining minutes will there be?there be?

(L) This IV started at 8:57 PM. What time (L) This IV started at 8:57 PM. What time will the bag empty?will the bag empty?

89


(M) An additional IV is ordered to run at (M) An additional IV is ordered to run at 60 mL/hr. The bag contains 2 grams 60 mL/hr. The bag contains 2 grams of medication dissolved in 500 mL of of medication dissolved in 500 mL of DD55W. The label specifies that the W. The label specifies that the normal dosage is from 1 to 4 mg/min. normal dosage is from 1 to 4 mg/min. What does the manufacturer consider What does the manufacturer consider the safe dosage range?the safe dosage range?

(N) At 60 mL/hr, what will be the (N) At 60 mL/hr, what will be the ordered dosage range in mg/hr?ordered dosage range in mg/hr?

90


(O) Is the order in part (N) a safe (O) Is the order in part (N) a safe dose?dose?

(P) If the physician were to order 1800 (P) If the physician were to order 1800 mg of the same medication at 70 mg of the same medication at 70 mL/hr, will the nurse accept or mL/hr, will the nurse accept or reject the order? Why?reject the order? Why?

91


30. Determine how many of combined 30. Determine how many of combined drug you will give the patient per drug you will give the patient per minute. Order: 22 mL/hr. If minute. Order: 22 mL/hr. If required, round to 3 decimal places.required, round to 3 decimal places.

Formulation: Formulation: Drug A – dissolve 70 mg/10 mL of D5WDrug A – dissolve 70 mg/10 mL of D5W

Drug B – dissolve 30 mg/15 mL of D5WDrug B – dissolve 30 mg/15 mL of D5W


31. Infuse an IV at 1,000 mL for the 31. Infuse an IV at 1,000 mL for the 1st 10 Kg of body weight, plus 50 1st 10 Kg of body weight, plus 50 mL/Kg per day for each Kg between mL/Kg per day for each Kg between 10 and 20. How many mL/hr should 10 and 20. How many mL/hr should the pump be set for a patient who the pump be set for a patient who weighs 19.5 Kg? Round to the weighs 19.5 Kg? Round to the nearest whole number. nearest whole number.

92

93

Answers to Solved Answers to Solved ProblemsProblems

1. mL = (1.5 mL/0.3 mcg) * (0.1 mcg/1)1. mL = (1.5 mL/0.3 mcg) * (0.1 mcg/1) = 0.5 mL= 0.5 mL

2. mL = (1.5 mL/8500 Units) * (3500 Units/1)2. mL = (1.5 mL/8500 Units) * (3500 Units/1) = 0.63 rounds down to: 0.6 mL= 0.63 rounds down to: 0.6 mL

3. mL = (10 mL/20 mEq) * (25 mEq/1)3. mL = (10 mL/20 mEq) * (25 mEq/1) = 12.5 mL= 12.5 mL

4. mL = (1 mL/1 mg) * (1 mg/1,000 mcg) * (750 mcg/1)4. mL = (1 mL/1 mg) * (1 mg/1,000 mcg) * (750 mcg/1) = 0.75 rounds up to: 0.8 mL= 0.75 rounds up to: 0.8 mL

5. mL = (2 mL/0.4 g) * (1 g/1,000 mg) * (300 mg/1)5. mL = (2 mL/0.4 g) * (1 g/1,000 mg) * (300 mg/1) = 1.5 mL= 1.5 mL

94


6. mL = (5 mL/1 tsp) * (3 tsp/1)6. mL = (5 mL/1 tsp) * (3 tsp/1) = 15 mL= 15 mL

mg = (3 mg/1 mL) * (15 mL/1)mg = (3 mg/1 mL) * (15 mL/1) = 45 mg= 45 mg

7. tsp = (1 tsp/5 mL) * (5 mL/25 mg) * (50 mg/1)7. tsp = (1 tsp/5 mL) * (5 mL/25 mg) * (50 mg/1) = 2 tsp= 2 tsp

8. mL = (5 mL/250 mg) * (1,000 mg/1 g) * (1.5 8. mL = (5 mL/250 mg) * (1,000 mg/1 g) * (1.5 g/1)g/1)

= 30 mL= 30 mL

95


9. tablets = (1 tablet/50 mg) * (1,000 mg/1 g) * (0.2 9. tablets = (1 tablet/50 mg) * (1,000 mg/1 g) * (0.2 g/1)g/1)

= 4 tablets= 4 tablets

10. mL = (10 mL/1,000,000 Units) * (200,000 Units/1)10. mL = (10 mL/1,000,000 Units) * (200,000 Units/1) = 2 mL= 2 mL

11. tablets = (1 tablet/0.1 g) * (1 g/1,000 mg)*(200 11. tablets = (1 tablet/0.1 g) * (1 g/1,000 mg)*(200 mg/1)mg/1)

= 2 tablets= 2 tablets

12. mL = 12. mL = (1.5 mL/500 mcg) * (1,000 mcg/1 mg) * (0.75 (1.5 mL/500 mcg) * (1,000 mcg/1 mg) * (0.75 mg/1)mg/1)

= 2.250 rounds down to: 2.25 mL= 2.250 rounds down to: 2.25 mL

96


13. mL = (5 mL/180 mg) * (360 mg/1)13. mL = (5 mL/180 mg) * (360 mg/1) = 10 mL= 10 mL14. mL = (5 mL/1 tsp) * (1 tsp/125 mg) * (500 14. mL = (5 mL/1 tsp) * (1 tsp/125 mg) * (500

mg/1)mg/1) = 20 mL= 20 mL15. mL/dose = (3 mL/175 mg) * (75 15. mL/dose = (3 mL/175 mg) * (75

mg/Kg/day) * mg/Kg/day) * (day/4 doses) * (1 Kg/2.2 lbs) * (day/4 doses) * (1 Kg/2.2 lbs) * (41 lbs/1)(41 lbs/1) = 5.993 rounds down to 5.99 = 5.993 rounds down to 5.99

mL/dosemL/dose

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16A. hr = (24 hr/3)16A. hr = (24 hr/3) = 8 hours= 8 hours16B. mL/dose = (1 mL/75 mg) * (15 mg/Kg/day) 16B. mL/dose = (1 mL/75 mg) * (15 mg/Kg/day)

* * (1 Kg/2.2 lbs) * (231 lbs/1) * (1 Kg/2.2 lbs) * (231 lbs/1) * (1 day/3 doses)(1 day/3 doses) = 7 mL/dose= 7 mL/dose17. mcg/g = (1,000 mcg/1 mg) * (1,000 mg/1 g)17. mcg/g = (1,000 mcg/1 mg) * (1,000 mg/1 g) = 1,000,000 mcg/g= 1,000,000 mcg/g18. mL = (15 mL/tbs) * (4 tbs/1)18. mL = (15 mL/tbs) * (4 tbs/1) = 60 mL= 60 mL

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19. gtt/min = (10 gtt/1 mL) * (500 mL/8 hr) * 19. gtt/min = (10 gtt/1 mL) * (500 mL/8 hr) * (1 hr/60 min)(1 hr/60 min) = 10.4 rounds down to 10 gtt/min= 10.4 rounds down to 10 gtt/min20. gtt/min = (60 gtt/1 mL) * (50 mL/2 hr) * 20. gtt/min = (60 gtt/1 mL) * (50 mL/2 hr) * (1 hr/60 min)(1 hr/60 min) = 25 gtt/min= 25 gtt/min21. Main bag stops flowing into the IV line 21. Main bag stops flowing into the IV line

until piggyback bag is empty.until piggyback bag is empty.22. mL/hr = (100 mL/2 hr)22. mL/hr = (100 mL/2 hr) = 50 mL/hr= 50 mL/hr

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23. mL/hr = (250 mL/90 min) * (60 min/1 hr)23. mL/hr = (250 mL/90 min) * (60 min/1 hr) = 166.66 rounds up to 166.7 mL/hr= 166.66 rounds up to 166.7 mL/hr24. mL/hr = (75 mL/90 min) * (60 min/1 hr)24. mL/hr = (75 mL/90 min) * (60 min/1 hr) = 50 mL/hr= 50 mL/hr25. mEq/day = (8 mEq/150 mL) * (25 mL/1 hr) * 25. mEq/day = (8 mEq/150 mL) * (25 mL/1 hr) * (24 hr/ day)(24 hr/ day) = 32 mEq/day= 32 mEq/day26. mcg/min = (1,000 mcg/1mg) * (150 mg/250 26. mcg/min = (1,000 mcg/1mg) * (150 mg/250

mL) *mL) * (10 mL/1 hr) * (1 hr/60 min)(10 mL/1 hr) * (1 hr/60 min) = 100 mcg/min= 100 mcg/min

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27. 27. orange juiceorange juice (6 oz * 30 mL/oz) (6 oz * 30 mL/oz) = 180 mL= 180 mLmilkmilk (4 oz * 30 mL/oz) (4 oz * 30 mL/oz) = 120 mL= 120 mLsyrupsyrup (1 oz * 30 mL/oz) (1 oz * 30 mL/oz) = 30 mL= 30 mLcoffee + milkcoffee + milk (8 oz * 30 mL/oz) (8 oz * 30 mL/oz) = 240 mL= 240 mLgelatingelatin (1/4 cup * 240 mL/cup)(1/4 cup * 240 mL/cup) = 60 mL= 60 mLapple sauceapple sauce (3 tbs * 15 mL/tbs) (3 tbs * 15 mL/tbs) = 45 mL= 45 mLinfusioninfusion (150 mL/hr * 8 hr) (150 mL/hr * 8 hr) =1,200 mL=1,200 mLmedicationmedication (2 tsp * 5 mL/tsp) (2 tsp * 5 mL/tsp) = 10 mL= 10 mLwaterwater (4 oz * 30 mL/oz) (4 oz * 30 mL/oz) = 120 mL= 120 mLsherbetsherbet (1 pt * 500 mL/pint)(1 pt * 500 mL/pint) = 500 mL= 500 mL

------------------------------ 2,505 mL 2,505 mL

(2,505 mL * 1,000 mL/liter) = 2.5 liters(2,505 mL * 1,000 mL/liter) = 2.5 liters

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28. 28. (A) hours = (1 hr/52 mL) * (450 mL/1)(A) hours = (1 hr/52 mL) * (450 mL/1) = 8.65 hours= 8.65 hours Not 8 hours and 65 Not 8 hours and 65

minutes!minutes! minutes = (60 min/hr) * (0.65 hr/1)minutes = (60 min/hr) * (0.65 hr/1) = 39 minutes= 39 minutes The bag will empty in 8 hours and 39 minutes The bag will empty in 8 hours and 39 minutes (B) 7 PM + 8 hours = 3 AM(B) 7 PM + 8 hours = 3 AM 47 minutes + 39 minutes = 86 minutes47 minutes + 39 minutes = 86 minutes 3 AM + 86 minutes = 3 AM + 86 minutes = 4:26 AM4:26 AM The clock will show The clock will show 4:26 AM.4:26 AM.

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29. 29. (A) How much fluid was lost?(A) How much fluid was lost? 200 urine + 2 * 75 diarrhea + 250 vomit = 600 mL200 urine + 2 * 75 diarrhea + 250 vomit = 600 mL

(B) The physician orders the existing drip (B) The physician orders the existing drip to continue as ordered PLUS an order to to continue as ordered PLUS an order to replace the lost fluid over the next hour. replace the lost fluid over the next hour. How much fluid will the nurse infuse How much fluid will the nurse infuse over the next hour?over the next hour?

600 replacement + 15 existing order = 615 mL600 replacement + 15 existing order = 615 mL

(C) How many drops/minute?(C) How many drops/minute? gtt/min = (15 gtt/mL) * (615 mL/60 min) = 154 mLgtt/min = (15 gtt/mL) * (615 mL/60 min) = 154 mL

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(D) In a separate IV, the patient is (D) In a separate IV, the patient is receiving 1350 Units/hr of a receiving 1350 Units/hr of a medication that is dispensed from a medication that is dispensed from a 500 mL bag containing 25,000 Units of 500 mL bag containing 25,000 Units of the drug through a the drug through a micromicro drip set. drip set. How many mL/hr are being infused?How many mL/hr are being infused?

mL/hr = (500 mL/25,000 Units) * (1350 Units/hr) = 27 mL/hrmL/hr = (500 mL/25,000 Units) * (1350 Units/hr) = 27 mL/hr

(E) How many drops/minute are being (E) How many drops/minute are being infused?infused?

gtt/min = (60 gtt/mL) * (27 mL/hr) * (hr/60 min) = 27 gtt/mingtt/min = (60 gtt/mL) * (27 mL/hr) * (hr/60 min) = 27 gtt/min

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The physician decides to increase the dosage The physician decides to increase the dosage by 3 Units/Kg/hr. The patient weighs 185 by 3 Units/Kg/hr. The patient weighs 185 pounds.pounds.

(F) How many Units/hr will the nurse (F) How many Units/hr will the nurse administer?administer?

Units/hr = (3 Units/Kg/hr) * (Kg/2.2 pounds) * (185 pounds/1) Units/hr = (3 Units/Kg/hr) * (Kg/2.2 pounds) * (185 pounds/1)

= 252 Units/hr + 1,350 Units/hr 1,602 Units/hr= 252 Units/hr + 1,350 Units/hr 1,602 Units/hr

(G) How many mL/hour will the pump be (G) How many mL/hour will the pump be set?set?

mL/hr = (500 ml/25,000 Units) * (1,602 Units/hr) = 32 mL/hr mL/hr = (500 ml/25,000 Units) * (1,602 Units/hr) = 32 mL/hr

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(H) How many gtt/min will be infused?(H) How many gtt/min will be infused? gtt/min = (60 gtt/mL) * (32 mL/hr) * (hr/60 min) = 32 gtt/min = (60 gtt/mL) * (32 mL/hr) * (hr/60 min) = 32

gtt/mmingtt/mmin

(I) How many hours will this IV run? (I) How many hours will this IV run? Express as a decimal quantity – 3 Express as a decimal quantity – 3 decimal places.decimal places.

hr = (hr/32 mL) * (500 mL/1) = 15.625 gtt/minhr = (hr/32 mL) * (500 mL/1) = 15.625 gtt/min

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(J) How many whole hours will the IV (J) How many whole hours will the IV run?run?

15 hours15 hours

(K) How many remaining minutes will (K) How many remaining minutes will there be?there be?

min = (60 min/hr) * (0.625 hr/1) = 38 minmin = (60 min/hr) * (0.625 hr/1) = 38 min

(L) This IV started at 8:57 PM. What time (L) This IV started at 8:57 PM. What time will the bag empty?will the bag empty?

8:57 PM + 15 hrs = 11:57 AM8:57 PM + 15 hrs = 11:57 AM 11:57 AM + 38 minutes = 11:95 AM = 12:35 PM11:57 AM + 38 minutes = 11:95 AM = 12:35 PM

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(M) An additional IV is ordered to run at 60 (M) An additional IV is ordered to run at 60 mL/hr. The bag contains 2 grams of mL/hr. The bag contains 2 grams of medication dissolved in 500 mL of D5W. medication dissolved in 500 mL of D5W. The label specifies that the normal dosage The label specifies that the normal dosage is from 1 to 4 mg/min. What does the is from 1 to 4 mg/min. What does the manufacturer consider the safe dosage manufacturer consider the safe dosage range?range?

1 to 4 milligrams per minute1 to 4 milligrams per minute

(N) At 60 mL/hr, what will be the ordered (N) At 60 mL/hr, what will be the ordered dosage range in mg/hr?dosage range in mg/hr?

(1 mg/min) (60 min/hr) = 60 mg/hr(1 mg/min) (60 min/hr) = 60 mg/hr

(4 mg/min) (60 min/hr) = 240 mg/hr(4 mg/min) (60 min/hr) = 240 mg/hr

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(O) Referring back to slide #104, is the (O) Referring back to slide #104, is the order inorder in

part N a safe dose?part N a safe dose? mg/hr = (1,000 mg/g) * (2 g/500 mL) * (60 mL/hr) = 240 mg/hrmg/hr = (1,000 mg/g) * (2 g/500 mL) * (60 mL/hr) = 240 mg/hr Yes it is a safe doseYes it is a safe dose

(P) If the physician were to order 1800 mg of (P) If the physician were to order 1800 mg of the same medication at 70 mL/hr, will the the same medication at 70 mL/hr, will the nurse accept or reject the order? Why?nurse accept or reject the order? Why?

mg/hr = (1,800 mg/500 mL) * (70 mL/hr) = 252 mg/hrmg/hr = (1,800 mg/500 mL) * (70 mL/hr) = 252 mg/hr Reject & question the order. It is (252 mg – 240 mg) =12 mg/hrReject & question the order. It is (252 mg – 240 mg) =12 mg/hr too large.too large.

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Answers to Solved ProblemsAnswers to Solved Problems

30. Determine how much of the combined drug you 30. Determine how much of the combined drug you will give the patient per minute. Order: 22 will give the patient per minute. Order: 22 mL/hr. If required, round to 3 decimal places.mL/hr. If required, round to 3 decimal places.

Formulation: Formulation: Drug A – dissolve 70 mg/10 mL of D5WDrug A – dissolve 70 mg/10 mL of D5W Drug B – dissolve 30 mg/15 mL of D5WDrug B – dissolve 30 mg/15 mL of D5W

You will dissolve and mix the 2 drugs as above. You will dissolve and mix the 2 drugs as above. This will yield 25 mL of combined drugs. Of the This will yield 25 mL of combined drugs. Of the 25 mL, you will give the patient 22 mL spread 25 mL, you will give the patient 22 mL spread over 60 minutes. The 70 & 30 mg are distracters.over 60 minutes. The 70 & 30 mg are distracters.

mL/hr = (22 mL/hr) * (hr/60 min) = 0.367 mL/hrmL/hr = (22 mL/hr) * (hr/60 min) = 0.367 mL/hr


31. 31. (a) Parse the total weight into 2 pieces: (19.5 Kg - 10 Kg) = 9.5 Kg (a) Parse the total weight into 2 pieces: (19.5 Kg - 10 Kg) = 9.5 Kg

(b) Calculate the infusion rate for the 1st 10 Kilograms:(b) Calculate the infusion rate for the 1st 10 Kilograms:

mL/hour = (1000 mL/24 hr) = mL/hour = (1000 mL/24 hr) = 41.66 41.66 mL/hourmL/hour

(c) Calculate the infusion rate for the remaining 9.5 Kilograms:(c) Calculate the infusion rate for the remaining 9.5 Kilograms:

mL/hour = (50 mL/Kg/day) * (9.5 Kg/1) * (1 day/24 hr) =mL/hour = (50 mL/Kg/day) * (9.5 Kg/1) * (1 day/24 hr) = 19.79 19.79 mL/hourmL/hour

(d) Combine the result of both calculations:(d) Combine the result of both calculations:

mL/hour = (41.66 + 19.79) = 61.45 mL/hour = (41.66 + 19.79) = 61.45

rounds to rounds to 61 61 mL/hourmL/hour

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Med-Math Calculations Med-Math Calculations for SJC Nursing Studentsfor SJC Nursing Students

A Dimensional Analysis ApproachA Dimensional Analysis Approach

THE END THE END

03/23/2008 @ 23:0003/23/2008 @ 23:00

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