Math For Meds For Medical Professionals : Math For Meds For Medical Professionals Caring 4 You Nursing Services www.caring4you.net www.facebook.com/nclex.review.90 Presented by: Anneliese Garrison, RN CLNC
Math For Medications : Math For Medications Metric System Fluid Dosage Calculations Tablet Dosage IV Drop Rate Calculations Dosage per weight
Metric Conversions : Metric Conversions 1. Convert 1750 ml to liters. 2. Convert 2 ½ liters to cc's. 3. Convert 0.75 g to mg.
Metric Conversions : Metric Conversions 4. Convert 250 mg to g. 5. Convert 5000 cc to liters. 6. Convert 5000 mcg to mg.
Metric Conversions : Metric Conversions 7. Convert 0.25 liters to ml. 8. Convert 60 mg to grains. 9. Convert 300 mg to grains. 10. Convert 2100 ml to liters.
Metric Conversions : Metric Conversions Know these conversions for the NCLEX Kg – lbs Cc / mL - Ozs Mg – G Gtts - mL
Fluid Conversions : Fluid Conversions This formula is used to calculate the amount of medication in solution for oral, intramuscular, intravenous or subcutaneous injection to be administered when given a dosage, stock dose and volume:
Fluid Conversions : Fluid Conversions Ordered Dose On Hand Volume ---------------------- X --------------------- On Hand Dose 1 (x factor) = Volume to be given
Fluid Conversions : Fluid Conversions Example: A client is ordered 15mg of stemetil. You have 2ml solution on hand which contains 25 mg Stemetil. What volume of solution would you give? 15 mg 2 mL 30 ------------- X ----------- = ------- = 1.2 mL 25mg x mL 25
Fluid Conversions : Fluid Conversions Example: A client is ordered 35 milligrams of Codeine phosphate by subcutaneous injection. 50 milligrams in 1 milliliter of liquid for SC Injection is available. How many milliliters will you administer? 35 mg 1 mL 35 ------------- X ----------- = ------- = 0.7mL 50 mg 1 50
Fluid Conversions : Fluid Conversions Example: A client is ordered 50 milligrams of Amoxicillin trihydrate orally. 125 milligrams in 5 milliliters of Syrup is available. How many milliliters will you administer? 50 mg 5 mL 250 ------------- X ----------- = ------- = 2 mL 125 mg 1 ( x mL ) 125
Fluid Conversions : Fluid Conversions Example: A client is ordered 30 milligrams of Frusemide intravenously. 10 milligrams in 1 milliliter of liquid for IV Injection is available. How many milliliters will you administer? 30 mg 1 mL 30 ------------- X ----------- = ------- = 3 mL 10 mg 1 (x mL ) 10
Fluid Conversions : Fluid Conversions Let’s figure this out together: A client is ordered 20 milligrams of Haloperidol decanoate by intramuscular injection. 50 milligrams in 1 milliliter of liquid for IM Injection is available. How many milliliters will you administer?
Fluid Conversions : Fluid Conversions Let’s figure this out together: A client is ordered 50 milligrams of Aminophylline intravenously. 250 milligrams in 10 milliliters of liquid for IV Injection is available. How many milliliters will you administer?
Fluid Conversions : Fluid Conversions Let’s figure this out together: A client is ordered 75 milligrams of Pethidine HCL by subcutaneous injection. 50 milligrams in 1 milliliter of liquid for SC Injection is available. How many milliliters will you administer?
Tablet Dosage Calculations : Tablet Dosage Calculations This formula is used to calculate the number of tablets to be administered when given the required dose. Ordered Dose ----------------------- = Number of dose to be given On Hand Dose
Tablet Dosage Calculations : Tablet Dosage Calculations Example A client is ordered 50 milligrams of Amitriptyline. 25 milligram tablets are available. How many tablets will you give? 50 mg ------------ = 2 tablets 25 mg
Tablet Dosage Calculations : Tablet Dosage Calculations Example A client is ordered 2.5 grams of Neomycin sulphate. 500 milligram tablets are available. How many tablets will you give? 1. First convert mg – grams 1000 mg = 1 g X mg = 2.5 g to find the “X factor”, you times diagonally and divide by the X (1000 x 2.5 / 1 = 2500 mg) so the order is for 2500 mg 2500 mg ------------- = 5 tablets 500 mg
Tablet Dosage Calculations : Tablet Dosage Calculations Example Ms. Thompson has Graves' disease and is prescribed methimazole 7.5 mg orally every morning. Her pharmacist fills the prescription with methimazole 5-mg tablets. How many tablets do you tell Ms. Thompson to take every morning? 5 mg = 1 tab ( 7.5 X 1 / 5) = 1.5 tabs 7.5 mg = X tab
Tablet Dosage Calculations : Tablet Dosage Calculations Example Sodium Seconal capsules are labeled 62.5 mcg. How many will you administer if the order is 0.125 mg? 1. Change mg’s to mcg’s . 1.1000 mcg = 1 mg 62.5 mcg = X mg = 0.0625 mg 2. 0.0625 mg = 1 tab 0.125 mg = X tab = 2 tablets
Tablet Dosage Calculations : Tablet Dosage Calculations Lets figure this out together: A client is ordered 150mg of aspirin. 300 mg aspirin tablets are available. How many tablets would you give?
Tablet Dosage Calculations : Tablet Dosage Calculations Lets figure this out together: A client is ordered 300 milligrams of Carbamazepine. 200 milligram tablets are available. How many tablets will you give?
IV Conversion Calculations : IV Conversion Calculations To measure the rate we must know: (a) the number of drops (b) time in minutes. The formula for working out flow rates is: volume (ml) X drop factor (drops/ml) ---------------------------------------------- time (min) = drops / minute
IV Conversion Calculations : IV Conversion Calculations Example: 1. 1500 ml IV Saline is ordered over 12 hours. Using a drop factor of 15 drops / ml, how many drops per minute need to be delivered? 1500 (ml) X 15 (drops/ml) ---------------------------------------------- 12 x 60 (gives us total minutes) = 31 drops / minute
IV Conversion Calculations : IV Conversion Calculations Example: 2. Calculate the drip rate for 100 mls of IV Fluids to be given over a half hour via a giving set which delivers 10 drops/ml. 100 (ml) X 10 (drops/ml) ---------------------------------------------- 30 (gives us total minutes) = 33 drops / minute
IV Conversion Calculations : IV Conversion Calculations Example: 3. One liter of Normal Saline is charted over 9 hours. The drop factor is 15. Calculate the number of drops per minute. 1000 (ml) X 15 (drops/ml) ---------------------------------------------- 9 X 60 (gives us total minutes) = 28 drops / minute
IV Conversion Calculations : IV Conversion Calculations Let’s Figure This Out Together One liter of Normal Saline is charted over 9 hours. The drop factor is 15. Calculate the number of drops per minute. 1. Change L – mL’s
IV Conversion Calculations : IV Conversion Calculations Let’s Figure This Out Together . You are required to administer 500 mls of Normal Saline over 3.5 hours. The drop factor is 10. How many drops per minute are required to start the flow off at the correct rate?
IV Conversion Calculations : IV Conversion Calculations Let’s Figure This Out Together One and a half liters of IV Fluids is prescribed over 8 hours. The drop factor is 15. How many drops per minute are required to start the flow off at the correct rate? 1. Change liters to mLs
Dosage / Weight Calculations : Dosage / Weight Calculations We never use pounds in medicine – it’s always kilograms. The first thing you need to do is convert the patient’s weight from pounds to kg. (Divide by 2.2) Then you multiply the dose (given in dose per kg) by the Weight in kg.
Dosage / Weight Calculations : Dosage / Weight Calculations Example: Solumedrol 1.5 mg/kg is ordered for a child weighing 74.8 lb. Solumedrol is available as 125 mg / 2mL. How many mL must the nurse administer? 74.8 lbs / 2.2 = 34 kgs 1.5 mg x 34 kg = 51 mg (give to client) 125 mg = 2 mL 51 mg = X mL Multiply diagonally and divide by the X 51mg x 2 mL divided by 125 mg = 0.82 mL
Dosage / Weight Calculations : Dosage / Weight Calculations NCLEX ALERT: Pay attention to the question if it says round to the nearest tenth, hundredth or thousandth. Ex. 10 th = 0. 8 46 100 th = 0.8 4 6 1000 th = 0.84 6 It is more likely the NCLEX will say “Mark you’re answer using one decimal place.” So 0.846 now becomes 0.8 if the next number was 5 or higher the answer would be 0.9 mL’s / gtts/ whatever
Dosage / Weight Calculations : Dosage / Weight Calculations NCLEX ALERT: When adding up fluid shift intake, don’t forget the IV! Ex. Fluid intake for 8 hour shift IV @ 125ml/hr = 125 mL x 8 hours = 1000 mL’s in an 8 hour shift Add this amount to the rest of your fluids. Many many times people make the mistake of adding just 125 mL when the question is asking for an amount in a specific amount of hours.
Dosage / Weight Calculations : Dosage / Weight Calculations Lets figure this out together: The nurse is caring for a client who has a prescription for Neoral (Cyclosporine) 2.5 mg/kg/day po in 2 divided doses. The client weights 160 lbs. The nurse has Neoral (Cyclosporine) 100 mg/mL available. How many mL should the nurse administer with each dose? Write your answer using one decimal place.
Dosage / Weight Calculations : Dosage / Weight Calculations Lets figure this out together: The nurse is caring for a 10 year old client who has a prescription for Ancef 7mg/kg po twice daily. The client weighs 66 lbs. The nurse has Ancef 125 mg / 5ml solution available. How many mL’s should the nurse administer with each dose? (Record your answer using a whole number)
Dosage / Weight Calculations : Dosage / Weight Calculations The nurse is calculating a client’s intake and output for an 8 hour shift. The client has had the following intake throughout the shift. 0.9% Sodium Chloride infusing at 125 mL /hr. 6 oz of chicken broth. 8 oz of apple juice. 4 oz of ice cream and 12 oz of carbonated beverages. How many mL should the nurse record as the clients fluid intake for the shift. The End