Drug Calculations Student workbook 2018 (2) (1) PDF

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Basic Numeracy and Drug Calculations Student Workbook Year 1(All Fields) Module: Fundamental Professional Skills for Nursing Practice Module code: M1B723331 Tri A-B (Feb 2020)

Drug Calcs worksheet originally developed by module team (ML Ingrid Rutherford) for EPCC module June 2014 Drug Calcs workbook: Reviewed, developed and updated February, 2020 for FPSNP

PART A: Introduction to medicine calculations & Student Preparatory work Medicines are the most commonly used clinical interventions and ensuring patient safety associated with the administration of medicine is challenging. All student nurses must be proficient in standard unit conversions to accurately calculate drug dosages. This is to ensure patients safety and minimise the number of medication errors caused by drug, dose and volume calculation errors. As a student nurse you will not administer a medicine on your own but will be supervised in the administration of medicine by your mentor/ registered nurse. Student Guidance on completing this workbook 1. This workbook contains some basic principles and calculations for the administration of some medications which are common across all fields of nursing practice. Whilst this workbook does contain an introduction to medicine calculations it is expected that students will supplement the information in this workbook with that of quality text books, quality journal articles and on-line web links and/or App of your choice. There is some suggested reading and on-line/App resources listed below in this booklet to help you get started. Students are not expected to read all underpinning reading/resources in Part A of course, but are free to browse the suggested reading & resources to access the sources they feel most useful and helpful in supplementing their learning. These are just suggestions and students are expected to add to their reading as they progress in their module and during placement 2 and placement 3. 2. Students are advised to firstly undertake some preparatory (of that listed below) prior to their skills seminar. Students can review any preparatory work listed below but I would recommend a mixture of resources including a quality text book/chapter, a journal article and at least one on-line tutorial for basic numeracy/conversions and basic drug calculations. Please note a lot of the work in this booklet will be completed in an on-going nature as your year 1 progresses. 3. In Part B of this workbook you will be re-introduced to some of the basic medicines calculations you have come across in your preparatory work. In our seminar class we will begin to work through some examples in this workbook in small groups of mixed fields. Students are expected to continue to work through their workbook (at their own pace) as the module progresses and during PLE 2 and PLE 3. The workbook should be completed by the end of year 1 and before proceeding into year 2. 4.

On-line learning and development tests on both numeracy and drug calculations will become active towards the end of the module. Students will be expected to undertake both of these learning tests and print off their completed test as evidence of undertaking this activity. Your PT can sign of the appropriate page in your mandatory training record in your S-OAR on production of your completed learning tests as evidence of completion. Further guidance on completion of the learning tests will be available as the module progresses. The idea is that students undertake the preparatory work and ongoing completion of this workbook prior to undertaking the learning tests.

5. This pack can either be printed off in its entirety and brought to skills seminar in hard-paper copy or if students prefer simply bring in their tablets, i-Pads, Laptops etc. in order to access it electronically in class. Either method is fine – as long as students can view the booklet in class

*Please note we use the word “tests” but please note that the grades for these tests do not form part of your formal module mark but are a mandatory part of the module. The tests are simply professional development and learning tests designed to support your learning in relation to medicine calculations. Students must complete both the numeracy learning test and the calculations learning test as this relates to your mandatory training record in your S-OAR for year 1,

Drug Calcs worksheet originally developed by module team (ML Ingrid Rutherford) for EPCC module June 2014 Drug Calcs workbook: Reviewed, developed and updated February, 2020 for FPSNP

Suggested Student Preparatory Work

Clinical skills. Net The clinicalskills.net is available on your GCU learn module site for this skills module. You can click on the clinicalskills.net on the left hand side of your screen to review the available resources. There are excellent examples of principles of drug administration and principles of drug calculations on this site. Please ensure you review the “procedures” section as it contains very useful resources in relation to administration of medication. Students can simply type into the Key Word Search Engine on screen “medicine” or “administration of medicine” or other relevant key search terms. This will flag up a variety of helpful resources to help you get started!

Suggested textbooks DONALDSON, J., 2013, Promoting the safe administration of Medicines in: Foundations for Nursing Practice, 2nd edn, eds BROOKER, C., & WAUGH., A.,Edinburgh: Mosby Elsevier, pp. 627-652 DOWNIE,G., MACKENZIE, J., & WILLIAMS, A., 2010, Calculating Drug Doses Safely, 2nd edn, Edinburgh: Churchill Livingstone GATFORD, J.D., & PHILIPS, N., 2011, Nursing Calculations, 8th edn, Edinburgh: Churchill Livingstone GLASPER, A., AYLOTT, M., & BATTRICK, C., 2010, Developing Practical skills for Nursing Children and Young People, London: Hodder Arnold LAPHAM, R., & AGAR, H., 2009, Drug Calculations for nurses: A step by step approach, 3rd edition, Arnold. London. *Please note the above book provides chapters on basic numeracy skills, developing this into drug calculations within a variety of contexts. Students are advised to dip in and out of the relevant chapters. *Child Field and dual registration students may also find “chapter 9 Paediatric dosage calculations” useful MCDONALD, W., NESS, V., TAYLOR, K., MCGUINNESS C. & Simpson, E., 2009 Mandatory Skills in: Foundation Clinical Nursing Skills, DOCHERTY, C., & MCCALLUM J., Oxford: Open University Press. pp 83-112. *Whilst all of the books highlighted above are useful for reviewing and practicing numeracy and drug calculations, in reality, any quality nursing/pharmacology textbook which focusses on drug calculations and numeracy will also be appropriate for this activity.

Drug Calcs worksheet originally developed by module team (ML Ingrid Rutherford) for EPCC module June 2014 Drug Calcs workbook: Reviewed, developed and updated February, 2020 for FPSNP

Journals BEANEY, A.M., 2010, Preparation of parenteral medicines in clinical areas: How can risk be managed? – A UK perspective. Journal of Clinical Nursing, 19 (11-12), pp. 1569-1577 COCOMAN, A., & Murray, J., 2008 intramuscular Injections: a review of best practice for mental health nurses. Journal of Psychiatric and Mental Health Nursing, Vol. 15, pp 424–434 DICKINSON, A., MCCALL, E., TWOMEY, B. & JAMES, N. 2010, Paediatric nurses’ understanding of the process and procedures of double checking medicines. Journal of Clinical Nursing, 19 (5-6), pp. 728-735 DOPSON, A. 2008, Confidence and competence in paediatric drug calculations. Nurse Prescribing, 6(5), pp. 208214 ELLIOT, M., & Liu, Y. 2010, The nine rights of medicine administration: an overview. British Journal Nursing. vol.19, no 5,pp.300-305 *Please note that these are just preliminary journal readings and that students are expected to add to their journal reading list by searching and reviewing relevant literature as they progress in their module, PLE 2 and PLE 3

On-Line Tutorials for Preparatory Work Recommended online site 1: SNAP The NHS website SNAP is an excellent online resource to support you in numeracy in health care. This website is strongly recommended to support and further enhance your learning in relation to health care numeracy. Please note that students need to REGISTER to use the site but after registration the Site is FREE to use Please use the URl noted to access the SNAP online learning resource http;//snap.nhs.uk/

Drug Calcs worksheet originally developed by module team (ML Ingrid Rutherford) for EPCC module June 2014 Drug Calcs workbook: Reviewed, developed and updated February, 2020 for FPSNP

Recommended online site 2: testandcalc The following URL provides a useful link to on-line numeracy/drug calculations. http://www.testandcalc.com/quiz/index.asp *** Please note that whilst you can try this site for free – downloadable software and further tutorials are at a price. As such please take care not to purchase anything you don’t wish to! 1.

Click on the URL above to access the website. If you have any difficulties opening the link then you can simply type in the URL in your search engine toolbar.

2.

Click on the link at the top of the page entitled “drug calculations quiz page”

3.

Links will appear in the middle of the page which lets you undertake drug calculations in relation to 4 main areas: Metric Conversions, Tablet Dosage Calculations, and Fluid Dosage Calculations and IV Drop rate calculations.

4.

Click on each individual test by clicking on “Quiz” and complete following the on-line instructions

5.

Please note that the site will provide the correct answer for you by clicking on “show me the answer link”.

*Alternatively students are free to access any other quality sites of their choice which provide on-line tutorials in relation to numeracy and drug calculations. The one given in this pack is only one example of the numerous resources which are available. MANY STUDENTS MAY ALREADY USE OR KNOW ABOUT A QUALITY APP TO SUPPORT YOUR ON-LINE LEARNING

Drug Calcs worksheet originally developed by module team (ML Ingrid Rutherford) for EPCC module June 2014 Drug Calcs workbook: Reviewed, developed and updated February, 2020 for FPSNP

Apps (Preparatory Work) There are also numerous Apps available for Smart phones, IPhones and tablets which can provide excellent resources and tutorials. Some Apps also provide reference sources and reading to support you’re learning Students may already be familiar with these already! • • • • •

Adult Drug Calculations (Epic Mobile): Free, some reasonable reviews Kids Drug Dosage Calc –PaedRx (logicmantra): Free, some reasonable reviews IV Drips (Jonsap): Small charge (under £2), some good reviews Nursecalcs (Jonsap): small charge (under £2), some good reviews LWW Nursing Drug Handbook (Lipincott Williams Wilkins), Free, useful but some reviews highlight technical problems with loading app and forced closure of app.

*Ultimately it’s the students’ choice as to which method they prefer to use in order to prefer for the learning tests. Some student may prefer on-line tutorials and some may prefer Apps – the choice is yours! Whichever resource you use please make sure you have accessed the core reading for the activity.

Part B: Introduction to Medicine Calculations Please ensure you have undertaken some of the suggested preparatory work highlighted in previous pages before completing all of this work-book. Please do not attempt completion of this workbook without undertaking the required student preparatory reading etc. Please don’t complete this workbook until after classes in weeks 5 & 6 of the module. We will begin to look at some examples in this workbook in tutorial classes but students are expected to work through and complete this workbook by the end of year 1. Please take your time when completing the workbook – there is no rush! The idea is that you complete it as your progress with your underpinning preparatory work during year 1 modules and PLE 2 & PLE 3. Drug Calcs worksheet originally developed by module team (ML Ingrid Rutherford) for EPCC module June 2014 Drug Calcs workbook: Reviewed, developed and updated February, 2020 for FPSNP

Revision of Basic Numeracy and Conversions There are 1000 micrograms in a milligram There are 1000 milligrams in a Gram There are 1000 Grams in a Kilogram

 Remember do not abbreviate 'micrograms'

Decimal Division Movement of the decimal point for division is: One figure to the left for every 10 units Two for every 100 units Three for every 1000 units, etc. Examples: To divide 35.9 by 100 the decimal point is moved 2 places to the left i.e. 0.359 This means that to express 15 micrograms as a decimal part of a milligram we would divide 15 by 1000 - i.e. to find how many micrograms there are as a part of 1000 the decimal point will be moved 3 places to the left as follows: micrograms 15

Divide by 1000

move decimal point by 3 to left

milligrams 0.015

Decimal Multiplication Movement of the decimal point for multiplication is by: One figure to the right for every 10 units Two for every 100 units Three for every 1000 units Examples: To multiply 35.9 by 100 the decimal point is moved 2 places to the right i.e. 3590.0 This means that to express 15 milligrams in micrograms we would expect there to be 1000 micrograms for each milligram as follows:

milligrams 15

Multiply by 1000

move decimal point by 3 to right

micrograms 15,000

1 Mega Unit = 1million units

Drug Calcs worksheet originally developed by module team (ML Ingrid Rutherford) for EPCC module June 2014 Drug Calcs workbook: Reviewed, developed and updated February, 2020 for FPSNP

Errors are commonly attributed to incorrect placement of the decimal point and using different measurements in the same calculation Generally convert to a common unit E.g. Add together 4 Kg, 55 G and 336 mgs Convert to Grams: 4 Kg x 1000 = 4000 G 55 G = 55 G 336 mgs /1000 = 0.336 G Total

= 4055.336 G

Measurements of Concentration Percent Solutions One way to express the quantity of a solute in a solution is as a percentage. This may be expressed in three ways: 1. Percentage Weight in Volume (%W/V) – The weight of the solute in grams per 100mLs of solution So a 100% solution would contain 100G in 100mLs and a 0.5% solution would contain 500mg in 100mLs 2. Percentage Volume in Volume (%V/V) – The volume of the solute in 100mLs of the solution i.e. 10mls in 100mls = a 10% solution 3. Percentage Weight in Weight (%W/W) – The weight of the solute or drug in relation to the weight of the solution i.e. the grams of drug dissolved in 100G of the solution – (Usually a mixture of two ointments) %W/V is by far the most commonly found expression For example: Dextrose 5% contains 5 Grams of dextrose per 100mls of dilutent Sodium Chloride 0.9% contains 900mgs of sodium chloride per 100mLs of dilutent

Drug Calcs worksheet originally developed by module team (ML Ingrid Rutherford) for EPCC module June 2014 Drug Calcs workbook: Reviewed, developed and updated February, 2020 for FPSNP

Ratio Concentration Here the ratio of drug is related to the volume of the solution For example: Adrenaline 1:1000 (the Units are Grams and MLs) So: 1g in 1000mLs =1000mg in 1000mls = 1mg in 1mL Displacement Volumes When reconstituting drugs in powder form the final volume of the dilutent can be increased, i.e. when 2grams of Ceftazidime is added to 10mLs of fluid the resultant total volume may now be around 12mLs. Therefore the displacement volume is 2mLs If the patient is prescribed 1.5g of Ceftazidime then 9mLs should be given – that is, for 3 quarters of the weight give 3 quarters of the volume.

Drug Calcs worksheet originally developed by module team (ML Ingrid Rutherford) for EPCC module June 2014 Drug Calcs workbook: Reviewed, developed and updated February, 2020 for FPSNP

There is no single right way to calculate drug dosages but there is one formula, in the form of an equation that always works. The formula is worth learning, but will be easier to remember if you know how it was constructed. Quantity to be given = Dose prescribed x Quantity given Dose Supplied Or What you want x What it’s in What you’ve got A child is prescribed 100mg fluconazole, which is supplied as capsules, each containing 50mg. The nurse must work out how many capsules to give. Two 50mg capsules would provide 100mg of drug – easy! Let’s look at how you got that answer: The dose prescribed, or what you want, was 100mg. The dose per available capsule, or what you’ve got, was 50mg. To get two capsules, you divided 100 by 50. Dose = 2 capsules 1. A child is prescribed oral chloral hydrate 250mg. The drug is available as an elixir containing 200mg in 5ml. 2. Prescription is oral phenobarbital (phenobarbitone) 45mg. It is available as 15mg in 5mL. 3. Metronidazole comes as 100mg in 20mL. The child is prescribed 75mg I.V. 4. Oral paracetamol 80mg is prescribed, it is available as syrup with 120mg in 5mL.

4. Baby is to have 25 microgram digoxin I.V.; it is available as 500 microgram in 2mL.

Drug Calcs worksheet originally developed by module team (ML Ingrid Rutherford) for EPCC module June 2014 Drug Calcs workbook: Reviewed, developed and updated February, 2020 for FPSNP

Injections Example: You are asked to draw up 15mmol of potassium chloride to be added to an infusion of sodium chloride. The ampoules in stock contain 20mmol in 10mL. How much should you draw up? The formula to be used: volume required = dose required/strength available x volume Therefore, the volume required = 15/20 x 10mL = 7.5mL to be drawn up 1. The digoxin in stock contains 500 micrograms in 2mL. You are asked to draw up 350 micrograms. 2. You are asked to draw up 120mg of erythromycin for injection. The stock vials contain 300mg in 10mL. 3. Stock heparin has a strength of 5000 units per mL. How much must be drawn up to give 6500 units? 4. A patient is to receive an injection of 60mg of gentamycin. Ampoules contain 80mg in 2mL. How much should you draw up? 5. An older adult man is to have 2.5 mg of Midazolam via IM injection. The stock ampoule available contains solution of 1mg per ml of Midazolam. How much (in mls) would you draw up to administer the IM injection. 6. A middle age woman is prescribed 5mg of Midazolam via IM injection. The 2mls stock ampoule available comes in 5mg/per ml . How much of the solution would you draw up to administer the IM injection? Tablets and mixtures Example: A patient is prescribed 0.25mg of digoxin orally. The tablets available contain 125 micrograms. How many tablets should the patient receive? First of all, you must put both strengths into the same units: 0.25mg = 250micrograms Formula = dose required/strength available Therefore the patient requires 250/125 = 2 tablets. Example: A patient is prescribed 800mg of penicillin suspension. The stock suspension contains 250mg in 5mL. What volume should you administer? Formula = dose required/strength available x volume of the strength available Therefore the patient requires 800/250 x 5mL = 16mL

Drug Calcs worksheet originally developed by module team (ML Ingrid Rutherford) for EPCC module June 2014 Drug Calcs workbook: Reviewed, developed and updated February, 2020 for FPSNP

1. A patient is prescribed 0.06g of codeine. The tablets available contain 30mg. How many tablets should you give him? 2. 450mg of aspirin is to be given. The available tablet strengths are 300mg and 75mg. How many tablets should be administered? 3. The patient is prescribed 1250mg of erythromycin suspension. The strength available is 250mg in 5ml. How much should be administered? 4. The patient is prescribed 1500mg chloral hydrate. The strength available is 1g in 10mL. 5. The patient is prescribed 1000mg of penicillin suspension. The available strength is 250mg in 5mL. How much should you giv...