Pediatric Math. Review of formulas: On hand: vehicle:: desired dose : x CONVERTING POUNDS TO KILOGRAMS: 2.2 pounds (lb) = 1kilogram (kg)

Transcription

1 Pediatric Math Children are more susceptible to medications than adults due to immature systems, metabolism and physical composition that can alter the pharmacokinetics of drugs. Therefore it is essential that everyone involved in the medication administration can accurately check the medications and ensure they are safe for the child. Nurses must be attentive to the 8 rights (right patient, right medication, right route, right time, right dose, right assessment, right education, right documentation). The nurse is also responsible to know if the dose is safe and therapeutic for their patient! It is essential for nurses to learn correct medication calculations in to ensure that each child receives a safe dose of medication within the therapeutic range. Review of formulas: Ratio and proportion: On hand: vehicle:: desired dose : x Basic Formula: Desired Have x vehicle Most medications will be ordered in mg/kg for infants and children. Also due to size and composition pediatric fluid requirements vary greatly than those of adults. Therefore it is necessary for nurses to be able to convert pounds to Kilograms (kg). CONVERTING POUNDS TO KILOGRAMS: 2.2 pounds (lb) = 1kilogram (kg) Try not to round kg when doing drug calculations, if it is necessary round to the nearest hundredth place (0.01) Example 1) Proportion 2.2lb:1kg:: 12.5lbs: x kg 2.2:1::12.5:x Basic Formula 2.2 lbs 1kg =12.5 lb x kg 2.2x=12.5 1

2 2.2x=12.5 x= 5.68 x = X= 5.68 Practice Questions: Convert the following pounds to kg 1) 38 lb kg 2) 16 lb kg 3) 42 lb kg 4) 60 lb kg 5) 8 lb kg 6) 12 lb kg DOSAGE PER KG OF BODY WEIGHT: Most medications for infants and children are ordered by kilograms of body weight. In order to calculate the dosage you need: a) A doctor s order that includes the medications name, the dose, and the frequency of administration. b) The child s weight. c) The Pediatric safe dose as listed in the by the manufacturer or hospital formulary and therapeutic range. (found in your drug book, or by calling the pharmacy) d) How the drug is supplied (what we have on hand). QUESTIONS WE NEED TO ASK ON ALL PEDIATRIC MEDICATIONS: When working with pediatrics we must know: 1) Is the dose safe? 2) Is the dose therapeutic? 3) Is it safe and therapeutic to give what the doctor ordered? 2

3 4) How will I give the medication? a. Specifically with oral medications and infants and small children ask can the child swallow pills? b. Can I crush this medication? c. Is this medication available in liquid form? DETERMINE IS THE DOSE SAFE and THERAPUTIC: 1) The doctor has ordered: Amoxicillin 75mg PO TID ANSWER: The child weighs 14lbs The pharmacy says that the dose for children 5< is 20-40mg/kg/day in 3-4 divided doses. Available is: Amoxicillin 125mg/5 milliliters First we need to change pounds to kilograms: 2.2lbs 1kg = x X= lb = x Second we find out if the dose is safe. (I always do this second because if it is not then we stop calculations here) ORDERED: amoxicillin 75mg TID SAFE: 40mg/kg/day or less THERAPUTIC: 20mg/kg/day or more So here I figure out how many mg/kg/day of amoxicillin the doctor has ordered for the client. So TID= three doses a day so we start by multiplying 75mg by 3dose/day 75mg/dose x 3dose/day= 225mg/day So our patient is getting 225mg of amoxicillin a day we then need to divide 225mg by 6.36kg to find mg/kg/day. 3

4 225mg/day 6.36kg = 35.38mg/kg/day Now since 35.38mg/kg/day is more than 20mg/kg/day it is therapeutic. Since 35.38mg/kg/day is less than 40mg/kg/day it is safe. IF A DOSE IS NOT SAFE WE DO NOT GIVE THE MEDICATION!!!! CALL THE DOCTOR and hold the medication until you have clarification. If the dose is not therapeutic I call the doc and let them know but still give the med. Now we need to know how many milliliters (ml) of the amoxicillin we need to give: ORDER: Amoxicillin 75mg PO TID AVAILABLE: Amoxicillin 125mg/5ml Ratio Proportion 125mg: 5 ml :: 75 mg: x Basic Formula 75mg 125mg x 5ml So we need 3ml of solution! GIVING THE MEDICATION: Oral Meds: Medications given orally can be supplied in many forms such as tablets, capsules, powders, and liquids (including elixirs, syrups, and suspension). Children under 5 are at risk for aspiration and normally have difficulty swallowing pills. If you are caring for a child 5 or under you should try to get the medication in liquid form. If the medication is only available in capsules or tabs than capsules can be opened, and tabs can be crushed. Then the powder can be mixed with a pleasant tasting liquid, and administered to the child. Never crush or open an enteric-coated tablet or time-release tablet or capsule. 4

5 LIQUIDS: Oral syringe: Droppers and med spoon: Medicine cup: Measuring spoons: g Liquids may be less concentrated at the top and more concentrated at the bottom so should be shaken prior to administration. Always use proper measuring equipment such as a medicine cup, measuring spoon, plastic oral syringe, or dropper to administer medication. DO NOT USE STANDARD HOUSEHOLD SPOONS FOR MEDICATION ADMINISTRATION! When giving liquid medications to children with a dropper or oral syringe place the tip of the dropper or syringe in posterior lateral section of the cheek. Give the medication slowly 0.2 to 0.5ml at a time and allow the child to swallow prior to giving more medication. Droppers and oral syringes are best for infants. Toddlers may prefer a spoon or cup. Older children may use a spoon, cup or syringe, whatever method they prefer. 5

6 RECTAL SUPPOSITORIES: Suppositories may be given to infants and young children when the oral route is unavailable. Suppositories for children may sometimes be cut in half. If this is the case cut it Lengthwise. Lubricant should be applied, use surgilube or water do NOT use Vaseline or other petroleum based lubricant because it will interfere with absorption. The suppository should be inserted above the internal anal sphincter and the buttocks should be held together for several minutes to prevent expulsion. The fifth finger should be used for insertion in children three and under, the index finger may be used in older children. INJECTIONS: Injections for pediatric patients differ than those in adults in that needle sizes must be smaller, muscles are smaller so therefore they absorb less fluid volume, and sites differ on children due to muscle development. Also the nurse may use EMLA crème to prevent pain during injections. IM INJECTIONS: In infants and small children injection sites differ from adults in that if a child is not walking we do not give injections in the ventrogluteal site. Also with infants and small children the deltoid is too small to use for injections. The preferred site for infants under 3 year is the vastus lateralis because it is the largest muscle in this age group. Also typically the Deltoid muscle is too small to use for IM injections in children under 3 years of age. AGE SITE LENGTH GAUGE (G) FLUID Infant Vastus lateralis 5/8 inch 25 G 1ml Toddler Deltoid 5/8 inch 25 G 0.5ml Vastus lateralis 1 inch 25 G 1ml Preeschool- School age Adolescent Ventrogluteal (if walking for 1 year) Deltoid Ventrogluteal Deltoid 1inch 5/8 inch 1 inch 5/8 inch 25 G 23 G 23G (may use 22g for viscous medications) 23G 1ml 0.5-1ml 2ml 1-1.5ml ventrogluteal 1 inch 23G(may use 22g for viscous medications 2-5ml 6

7 Administering Ear drops: For children fewer than 3 years of age, pull the ear down and back. For children over 3 years of age and adults, pull the ear up and back. EXAMPLES: 1) You are caring for a 2 month old infant weighing 6.36 kg. The doctor has ordered Tylenol 80mg PO q6hr PRN. We find that Tylenol is available in: infant suspension 80mg/0.8ml, in a liquid 160mg/5ml, chewable tabs 81mg/tab, tablets 250mg/tab, suppositories 80mg, and 120mg. (We can find how medications are available in the drug book or by calling the pharmacy). a) Which form of medication would you give? b) How would you administer it? Answer: The best method would be the Tylenol Suspension, because it is an oral liquid which would be the most appropriate for the age (and less invasive than a suppository), and the suspension allows the nurse to administer less fluid therefore decreasing the risk for aspiration. The best method for administration would be a dropper or an oral syringe to properly put the liquid into the cheek pocket in the mouth. 2) You are caring for a 4 year old child requiring ear drops. Which way will you pull the ear to administer the drops? Answer: In children over 3 the ear is pulled up and back. 3) You are preparing to administer a DTaP vaccine to a 2month old infant. The nurse knows that the DTaP is an IM injection of 0.5ml. a. What muscle will you give the injection in? 7

8 b. What length needle will you use? c. What gauge needle is appropriate? Answer: The nurse would expect to give the injection in the Vastus lateralis, using a 5/8inch 25G needle. 4) The nurse is preparing to give Acetaminophen to a 5year old girl weighing 20kg. The doctor has ordered Acetaminophen 200mg PO q6hr PRN pain. Use the drug formulary in the back to see how the drug is supplied. a. What would be the best method to administer this medication? Answer: This was a trick question at 5 years of age the child may take oral liquids chewable pills. Either of these would be an appropriate answer. In the clinical setting the nurse would want to check with the parent to see what method would be best. PRACTICE QUESTIONS: Use the drug formulary in the back of the packet to complete these problems 1) You are caring for a 10 year old child weighing 30kg. The doctor has ordered cephalexin 500mg po Q6 hrs. Use the drug formulary in the back to complete this problem. a. Is the dose safe and therapeutic? b. Will you give a tablet or liquid form? c. What strength will you give? d. How much will you give? 2) You are caring for a 2 year old child weighing 12kg. The doctor has ordered Prednisolone 12mg PO BID x 7 days. a. Is the dose safe and therapeutic? b. Will you give liquid or tabs? 8

9 c. How will you administer the medication? Please describe the steps: d. How much medication will you give? (Use the 15mg/5ml concentration because 12 ml. is a lot of medication for a 2 y/o to swallow) 3) You are caring for a 1 year old child with otitis externa. The doctor has ordered Ofloxacin 5gtts to the left ear BID. a. Is this a safe dose? b. How will you administer this medication? (include client position) PEDIATRIC FLUID MAINTENANCE: Due to children s immature organ systems, smaller size and larger body surface area children s fluid requirements differ greatly from adults. To calculate an infant or child s maintenance fluid requirements we use the formula below: Always convert weight from pounds to kilograms for pediatric fluids as well as medications! 100ml/kg for the first 10kg of body weight 50ml/kg for the next 10 kg of body weight 20ml/kg for every kg over 20 kg We use this formula to calculate the hourly rate of IV fluid the child should receive in order to prevent fluid volume imbalances. Now remember when calculating maintenance fluid is just the fluids required to maintain a normal fluid balance if a child is not drinking. In cases of dehydration the child may be receiving more fluids, and with cardiac or renal problems the requirements may be less. 9

10 EXAMPLE CALCULATING FLUID VOLUMES: 1) If the child weighs 23 kg what would the daily fluid volume be? 100 ml/kg for the first 10 kg = 1000ml 50ml/kg for the next 10kg = 500ml 20ml/kg for the next 3kg = 60ml TOTALS: 23kg = 1560 ml/day 2) If the child weighs 8 kg what would the daily fluid volume be? 100ml/kg x 8kg= 800ml/day 3) If the child weighs 12 kg what would the daily fluid volume be? 100ml/kg for the first 10kg = 1000ml 50ml/kg for the next 2kg = 100ml TOTALS 12kg = 1100ml/day PRACTICE QUESTIONS FOR FLUID VOLUMES: 1) Calculate the daily fluid volume for a 6kg child: 2) Calculate the daily fluid volume for a 14kg child: 3) Calculate the daily fluid volume for a 16kg child: 4) Calculate the daily fluid volume for a 4kg child: 5) Calculate the daily fluid volume for a 32kg 6) Calculate the daily fluid volume for a 44 pound child: CALCULATING HOURLY IV RATE FROM DAILY FLUID VOLUME REQUIREMENTS: 10

11 Due to children s small size and immature systems children are at higher risk for fluid volume imbalances than adults. Therefore it is extremely important for the nurse to be able to identify if the child is getting appropriate fluid maintenance for their size. If the child is not receiving normal maintenance fluids the nurse should be asking why! 1) If the child weighs 23kg and we already calculated the daily requirements of 1560ml/day. You simply divide 1560ml by 24 because there are 24 hours in a day: We round to the nearest ml. and the answer is: 65ml/hr 1) If the child weighs 8kg we have calculated that the child need 800ml/day: 800ml/day 24hr/day = 33.33ml/hr, so we round to 33ml/hr 2) If the child weighs 12kg and we have calculated the child needs 1100ml/day: 1100ml/day 24hr/day = 45.83, so we round to 46ml/hr PRACTICE CALCULATING HOURLY FLUID VOLUME: 1) Calculate hourly fluid requirement for a 7kg child: 2) Calculate hourly fluid requirements for a 13kg child: 3) Calculate hourly fluid requirements for a 18kg child: 4) Calculate hourly fluid requirements for a 44kg child: 11

12 CALCULATIONS FOR IV ANTIBIOTICS: When administering IV antibiotics to infants and children we must do many more calculations than when giving an adult an antibiotic. Most pediatric antibiotics must be reconstituted and then diluted for administration. In order to give the medication safely the nurse must know: 1) how to reconstitute a powdered medication 2) how much medication to draw up 3) the maximum concentration of medication for dilution 4) the amount of time the medication needs to be infused over. #1 RECONSTITUTION: Reconstitution is adding liquid to a powder to make a new solution. Most antibiotics are received in a powder form and the nurse must add a liquid (normally sterile water or saline) in order to prepare the medication for administration. Information on how to reconstitute can be found either on the drug label, on formularies provided by your facility, or the nurse can call the pharmacy. The nurse knows how much medication to draw up after s/he reconstitutes the medication. The doctor has ordered Ampicillin 500 mg IV TID for a child weighing 28kg. The normal pediatric dose is mg/kg/day in divided doses Step 1: Is the dose safe? Is it therapeutic? Normal is mg/kg day; the child weighs 28kg. The child is getting 500mg TID (3x day) which = 1,500mg/day So to find if it is therapeutic we multiply 50mg x 28kg= 1400mg To find out if it is safe we multiply 28kg x 200mg= 5600mg 12

13 So if the daily dose ordered for the child is over 1,400 it is therapeutic and if it is under 5600mg it is safe. Our child s daily dose is 1,500mg so it is safe and therapeutic. Step 2: We reconstitute the medication So from the label above we can reconstitute the medication with 1.8 ml of diluent and the resulting concentration will be 250mg/ml Note that the bottle says for IM use to reconstitute with 1.8ml of solution, but we can reconstitute medications the same for IV or IM use, but often the medication must be further diluted for IV use. Step 3: We draw up the medication So from the reconstitution above we know we have 250mg/ml of Ampicillin. Again, the doctor s order is 500mg IV TID Ratio and Proportion 250mg/ml: 1ml:: 500mg: x Basic Formula x1ml = 2m 13

14 PRACTICE RECONSTITUTION: The doctor has ordered Cefzil 150mg PO BID for a 10kg toddler. Available on the floor is a bottle of powder with the label below. How much diluent will you add to the bottle? What will the resulting concentration be? (mg/ml) How much medication will you draw up? The normal pediatric dose is 15-25mg/kg/day: Is the dose safe? Is it therapeutic? 14

15 1) The doctor has ordered cefazolin 120mg a day for a 4kg neonate. The normal neonatal dose is 60mg/kg/ day Is the dose safe? Using the label above how much diluent would you add to the bottle? What will the resulting concentration be? How much medication will you draw up? DILUTING AND ADMINISTERING IV MEDICATIONS: After we have figured out if the medication is safe for the patient, reconstituted the med and drawn the medication up for delivery often we need to dilute the medication further for delivery. There will be safe administration concentrations that you can find in the drug book, by calling the pharmacy and on facility drug formularies. Also the nurse must know the length of time the medication is to be given over. This information can be found in your drug book. For all practice problems in this packet the information is provided under Drug formularies in the back. 15

16 Let s Try it!!! #1) The doctor has ordered Ampicillin 500 mg IV TID for a child weighing 28kg. The normal pediatric dose is mg/kg/day in divided doses 1) Is the dose safe? Is it therapeutic? Normal is mg/kg day; the child weighs 28kg. The child is getting 500mg TID (3x day) which = 1,500mg/day So to find if it is therapeutic we multiply 50mg x 28kg= 1400mg To find out if it is safe we multiply 28kg x 200mg= 5600mg So if the daily dose ordered for the child is over 1,500 it is therapeutic and if it is under 5600mg it is safe. Our child s daily dose is 1,500mg so it is safe and therapeutic. 2) Reconstitute the Medication: So from the label above we can reconstitute the medication with 1.8 ml of diluent and the resulting concentration will be 250mg/ml 3) Draw up the medication: If we have 250mg/ml and need 500mg 500mg 250mg x 1ml= 2ml 4) Dilute the medication: So we go to the drug Formulary in the back and find that the maximum concentration for administration is 45mg/ml We have 500mg So we divide 500mg by 45mg 500mg 45mg/ml = 11.1ml So the minimum amount of fluid you can put it in is 11ml for administration. 16

17 5) Administer the medication: The medication needs to be administered over 15-30minutes. We get this information from the drug formulary. So if we are going to give it over 30 minutes (1/2hr) than we divide 11ml by 0.5hr 11ml 0.5hr =22ml/hr So we put the rate at 22ml/hr #2) The doctor has ordered Cefazolin Sodium 700mg Q6hr. You are caring for a child weighing 45 kg. Available is a 1gm vial. 1) Is the dose safe? Is it therapeutic? Normal is mg/kg day (we got this from the drug formulary in the back); the child weighs 45kg. The child is getting 700mg 4x day which = 2800 mg/day So to find if it is therapeutic we multiply 50mg x 45kg= 2250mg To find out if it is safe we multiply 45kg x 100mg= 4500mg So if the daily dose ordered for the child is over 2250it is therapeutic and if it is under 4500mg it is safe. Our child s daily dose is 2,800mg so it is safe and therapeutic. 2) Reconstitute the Medication: So from the drug formulary we find 1gm reconstitute with 2.5ml of sterile water to yield 330mg/ml. 3) Draw up the medication: If we have 330mg/ml and need 700mg 700mg 330mg x 1ml= 2.12ml 4) Dilute the medication: So we go to the drug Formulary in the back and find that the maximum concentration for administration is 20mg/ml We have 700mg So we divide 700mg by 20mg 700mg 20mg/ml = 35ml 17

18 So the minimum amount of fluid you can put it in is 35ml for administration. We can dilute it further!! 5) Administer the medication: The medication needs to be administered over 5 minutes. We get this information from the drug formulary. So if we are going to give it over 5 minutes (1/12hr) than we divide 35ml by 1/12hr. = 420ml/hr So the fastest rate we can give the med is 420ml/hr. We can give it slower!!! PRACTICE GIVING IV ANTIBIOTICS: 1) The doctor has ordered Nafcillin 225mg q4hr. The nurse is caring for a patient weighing 18kg. Available is Nafcillin 1gm. a. Is the dose safe and therapeutic? b. How much fluid will you use to reconstitute the medication? c. How many milligrams per milliliter will there be after reconstitution? d. How many milliliters will the nurse draw up? e. How much fluid will you dilute it with? f. How fast can you give the medication? g. What will the fastest rate you could give it at? (in ml/hr) 18

19 2) You are caring for an infant weighing 5kg. The doctor has ordered Ceftazidime 140mg Q8hr. Available is Ceftazidime 500mg. a. Is the dose safe and therapeutic? b. How much fluid will you use to reconstitute the medication? c. How many milligrams a milliliter will there be after reconstitution? d. How many milliliters will the nurse draw up? e. How much fluid will you dilute it with? f. How fast can you give the medication? g. What will the fastest rate you could give it at? (in ml/hr) 3) The doctor has ordered Cefazolin 350mg Q6hr. You are caring for a 33lb child. Available is: a. Is the dose safe and therapeutic? b. How much fluid will you use to reconstitute the medication? 19

20 c. How many milligrams a milliliter will there be after reconstitution? d. How many milliliters will the nurse draw up? e. How much fluid will you dilute it with? f. How fast can you give the medication? g. What will the fastest rate you could give it at? (in ml/hr) 4) You are caring for the infant below, who weighs 12 kg. The doctor has ordered the Hib vaccine for this infant. a) Where would you expect to administer this vaccine? b) What size needle should be used? c) What gauge needle should be used? 5) The nurse is planning to give eardrops to the child pictured below. In which direction should the nurse pull the ear to straighten the canal? 20

21 DRUG FORMULARY-Information provided in this drug formulary should only be used to answer the questions in this math packet. This is NOT a drug book and this information is NOT to be used in the clinical setting. Acetaminophen (Tylenol) Analgesic/ antipyretic Available- Tab: 160, 325, 500, 600mg Chewable Tabs: 80mg, 160mg Infant drops, solution/suspension: 80mg/0.8ml Oral Liquid: 160mg/5ml Caplet: 500mg Extended release gel tab: 650mg Suppositories: 80, 120, 325, 650mg Pediatric Dosage: Ampicillin Antibiotic Available- PO: 10-15mg/kg/dose PO/PR Q4-6hr Suspension: 125mg/5ml, 250mg/5ml Cap: 250, 500mg Injection: 125mg, 250mg, 500mg, 1.5gm and 3gm vials Pediatric dosage: PO: mg/kg/day in 2 divided doses IV: mg/kg/day in 4 divided doses 21

22 Reconstitution- Dilute- 250mg reconstitute with 0.9ml of sterile water to yield 250mg/ml 500mg reconstitute with 1.8ml of sterile water to yield 250mg/ml 1.5gm reconstitute with 3.2ml of sterile water to yield 375mg/ml Further dilute with NS, D5W, D5/NS, or LR to a final concentration of 3-45mg/ml for administration. Administer over at least minutes. CEFAZOLIN SODIUM (Kefzol, Ancef) Antibiotic first generation cephalosporin Available- Injection: 250mg, 500mg, 1gm, 5gm, Pediatric Dosage: mg/kg/day in 4 divided doses Reconstitution- Dilute- 250mg reconstitute with 2ml of sterile water to yield 125mg/ml 500mg reconstitute with 1.8ml of sterile water to yield 250mg/ml 1gm reconstitute with 2.5ml of sterile water to yield 330mg/ml Further dilute with NS, D5W, D5/NS, to a final concentration of 20mg/ml for administration. Administer over 5min or longer. CEFTAZIDIME (Fortaz) Antibiotic 22

23 Available- Injection: 500mg, 1gm Pediatric Dosage: mg/kg/day in 3 divided doses Reconstitution- Dilute- 500mg reconstitute with 1.5ml of sterile water to yield 280mg/ml 1g reconstitute with 3ml of sterile water to yield 280mg/ml Further dilute with NS, D5W, or LR to a final concentration of 7mg/ml for administration. Administer over at least minutes. CEPHALEXIN (Keflex) Antibiotic first generation cephalosporin Available- Tabs: 250mg, 500mg Caps: 250mg, 500mg Suspension 125mg/5ml, 250mg/5ml Pediatric Dosage: PO: mg/kg/day in 4 divided doses NAFCILLIN (Nallpen) Antibiotic Available- Injection: 1gm, 2gm Pediatric Dosage: mg/kg/day in 4 to 6 divided doses 23

24 Reconstitution- Dilute- 1gm reconstitute with 3.4ml of sterile water to yield 250mg/ml 2gm reconstitute with 6.8ml of sterile water to yield 250mg/ml Further dilute with NS, D5W, D5/NS, to a final concentration of 30mg/ml or less for administration. Administer over 30-90min. OFLOXACIN (Floxin, Floxin Otic) Antibiotic Available- Optic solution: 0.3% Opthalmic solution: 0.3% Tabs: 200, 300, 400mg Pediatric Dose: Otitis Externa: 1yr-12yr 5gtts to affected ear(s) BID. >12yrs 10gtts to affected ear(s) BID. Ophthalmic: >1yr 1-2gtts q 2-4hr PREDNISOLONE (Prelone) Corticosteroid Available- Tab: 5mg Syrup: 5mg/5ml, 15mg/5ml Pediatric Dosage: PO: 0.5-2mg/kg/day in 2 to 4 divided doses. Max dosage 80mg/24hr. 24

25 CEFPROZIL (Cefzil) Antibiotic Available- Injection: 250mg, 500mg, 1gm, 5gm, Pediatric Dosage: mg/kg/day Reconstitution- Dilute- 250mg reconstitute with 2ml of sterile water to yield 125mg/ml 500mg reconstitute with 1.8ml of sterile water to yield 250mg/ml 1gm reconstitute with 2.5ml of sterile water to yield 330mg/ml Further dilute with NS, D5W, D5/NS, to a final concentration of 15mg/ml for administration. Administer over 5min or longer. 25

26 References Robertson, J. & Shilkofski, N., (2005) The Harriet Lane Handbook: Seventh Edition. Philadelphia, PA; Mosby Wilson, Shannon, Shields, & Stang (2007) Nurses Drug Guide. Upper Saddle River, NJ; Prentice Hall. Kee, J. L., Marshall, S. M., (2004) Clinical Calculation: Fifth Edition. St. Louis, MO; Saunders. 26