Dosage Calculation Tutorial - Kent State University

1 Dosage Calculation TutorialKent State University Regional CampusesKarol Burkhart Lindow, RN,C, MSN, CNSA ssociate Professor, NursingReviewers:Denise Ayers, RN, MSNJoan Lappin, RN, MSNS ummer 2004copyrightc 2004 Kent State UniversityContentsAcknowledgements41 What is Dosage Calculation ?.. Doesn t the pharmacist do all this?.. I thought the doctor was the one responsible for medicationsafety?.. How can I be successful in calculating dosages?..62 Basic Math Whole Numbers.. Multiplying Whole Numbers.. Dividing Whole Numbers.. Fractions.. Multiplying Fractions.

2 Dividing Fractions.. Decimals.. Adding Decimals.. Subtracting Decimals.. Multiplying Decimals.. Dividing Decimals.. Changing Fractions to Decimals.. Additional Help with Math..153 Systems of Measurement and Common The Metric System.. The Apothecary System.. The Household System.. Summary.. Conversion Practice.. Summary of the Essential Equivalents..204 Abbreviations215 Calculation Basic Formula.. Ratio-Proportion Formula.. Dimensional Analysis Formula..256 Calculating Oral Calculation Practice Problems.. Problem Set I.. Problem Set II.

3 Case Studies.. Case Study 1.. Case Study 2..327 Calculating Injectable Injection Routes.. Packaging of Injectable Medications.. Types of Syringes.. Types of Needles.. Calculations for Injectables.. Giving Insulin Injections.. Calculation Practice Problems.. Problem Set III.. Problem Set IV.. Case Studies.. Case Study 3.. Case Study 4..448 Calculating Intravenous Medications and Drip Intravenous Medications.. Intravenous Solutions.. Infusion Pumps.. Gravity Flow.. Calculation Practice Problems.. Problem Set V.. Continuous Medication Infusions.

4 Calculation Practice Problems.. Problem Set VI.. Case Studies.. Case Study 5.. Case Study 6..539 Answers to Basic Math Review.. Multiplying Whole Numbers.. Dividing Whole Numbers.. Multiplying Fractions.. Dividing Fractions.. Writing Decimals.. Which is smaller?.. Adding/Subtracting Decimals.. Multiplying/Dividing Decimals.. Conversion Practice.. Answers to Calculation Practice Problems.. Problem Set I.. Problem Set II.. Problem Set III.. Problem Set IV.. Problem Set V.. Problem Set VI.. Answers to Case Studies.. Case Study 1.

5 Case Study 2.. Case Study 3.. Case Study 4.. Case Study 5.. Case Study 6..66 Bibliography67 AcknowledgementsSincere appreciation is extended to the following faculty for their expertiseand invaluable assistance in creating this Tutorial : Dr. Beth Osikiewicz, As-sistant Professor, Mathematics and Dr. Jeff Osikiewicz, Associate Professor, 1 IntroductionDosage Calculation is a mandatory skill for nurses in any clinical medication administration is one of the primary roles of clinical nurses,being able to calculate correct dosages is paramount to safe practice.

6 Publicand professional literature has documented that improper Dosage calcula-tions are a common source of medication errors. Medication errors dueto improper Dosage Calculation can have serious, even fatal, attention to the Calculation and administration of correct dosagesmust be a priority for nurses. Therefore, strong emphasis is placed on dosagecalculation throughout the nursing school curriculum. Also, most healthcarefacilities now require nurses to demonstrate competence in Dosage calcula-tion before being What is Dosage Calculation ?Literally, Dosage Calculation means figuring out the correct dose of a medica-tion.

7 Many times the medication dose prescribed for the patient is differentfrom the way the medication is example, an order may be written for the patient to receiveAmoxi-cillin 500mg, but the medication that comes from pharmacy isAmoxicillin250mgper tablet. You calculate that the patient needs to take 2 tablets toachieve the full 500mg dose that was ordered. Of course, that Calculation ispretty obvious and can be done in your head .But how about this order:Morphine 15mginjection and the suppliedmedication isMorphine 1/2 grain per milliliter. With this situation, you willneed to convert the grain (gr) Dosage to milligrams (mg) and then calculatethe correct Dosage .

8 You will also need to be familiar with the DOESN T THE PHARMACIST DO ALL THIS?6on syringes in order to prepare this medication for administration to above examples point out some of the factors related to dosagecalculation which you will be learning in this Tutorial . These include: Abbreviations used in medication administration Systems of measurement Basic mathematical calculations Formulas for computing drug Doesn t the pharmacist do all this?All too frequently, nursing students do not take Dosage Calculation seriouslybecause they think the pharmacist does all the calculating.

9 Yes, most fa-cilities now have unit dosing (a system in which each patient receives themedications ordered specifically for them). However, as the examples abovepoint out, the medication supplied is often in a Dosage or form that is dif-ferent from what is ordered. Pharmacists will not calculate each individualdose. That is the nurse s responsibility. You are the person giving the med-ication; you are the person responsible for the safe, correct administrationof that medication! I thought the doctor was the one responsiblefor medication safety?Of course, the person prescribing the medication has responsibilities for theappropriate, safe use of that medication.

10 However, the person who givesthat medication to the patient also has a big responsibility to assure thatthe medication is safe and therapeutic. Nurses are held accountable for theiractions! One of the first steps for assuring safe medication use is to assurethat the correct Dosage is being How can I be successful in calculating dosages?There are 3 big steps to successfully calculating medication competent in basic math HOW CAN I BE SUCCESSFUL IN CALCULATING DOSAGES? the measurement equivalents and Calculation formulas correctlyThis Tutorial will help you become proficient in each of these steps.