Base Hospital 2003 Fall Recerts. Medical Math and Drug Calculations

2 Milligrams Milliliters Kilograms mg/kg/min ml/cc gtts/min mg Making Sence of Medical Math

3 Pre/Post Course Math Overall well done Some problems were found in the Precourse –Paramedics did not show their work, therefore it was hard to determine the problem.

4 Calculators and medication tables are more than welcome, only if you intend on using them in your practice. You are encouraged to use the formulas supplied. If you have your own method and it works for you, do it your way.

5 Where will I apply medical math??

6 WANT = AMOUNT TO ADMINISTER HAVE HOW MUCH TO ADMINISTER

7 WANT Protocols I.e. 0.3mg Epi. 1:1,000 SC Verbal Orders by patch phone Written Orders on Patient chart

8 HAVE Concentration of the Drug –Nitro, Salbutamol, Glucagon, Lidocaine, etc. Contents of the IV Bag Amount in a given Ampoule or Vial

9 Weight vs. Volume REMEMBER Weight and Volume are not the same thing Weight is the amount of a drug -5.0mg of Ventolin Volume is the amount of fluid the drug is dissolved in ml nebule

10 Have = Concentration Concentration = Volume Weight

11 Concentration mol/L G/L G% or % mg% Eq/L m/Eq/L mg/ml mcg/ml moles per litre grams per litre grams/100mL mg per 100 mL equivalents/ L milliequivalents per litre milligrams/millilitre micrograms/millilitre

12 Concentration Reduce the Volume to 1 ml which will make the math easier 100 mg in 20 ml = 250 mg in 100 ml = 60 mg in 15 ml = 5 mg/ml 2.5 mg/ml 4 mg/ml mg/ml

13 = Amount to Administer (ml) Concentration Amount Ordered 5 mg/ml 5 mg/2.5ml 5mg/2ml 50 mg = 10 ml 1 mg/ml 0.3 mg = 0.3 ml 0.3 mg = 0.12 ml 1.25 mg = ml Injection - ml

14 = Amount to Administer (ml/min) Concentration Amount Ordered 200 mcg/ml 10 mg/ml 10 mg/ml 5 mg/ml 5 mg/ml 20 mcg/min = 0.1 ml/min 15 mg/min = 3 ml/min 3 mg/min = 0.3 ml/min Infusion - ml/min = 1 mcg/min 10 mcg/ml

15 = Amount to Administer (gtt/min) Concentration Amount Ordered 200 mcg/ml 20 mcg/min = 6 gtt/min = 6 gtt/min Infusion gtt/min X drip factor x 60 gtt/ml = 0.1ml/min 15 mg/min 5 mg/ml 5 mg/ml = 180gtt/min 3 mg/min 10 mg/ml 10 mg/ml = 18gtt/min

16 =Amount to administer (ml/min) Concentration Amount Ordered 800 mcg/ml 10 mcg/kg/min = 1ml / min If drop/ minute are required multiply by drop factor = 60 gtt/min Weight Based Infusion x Weight Factor x 80 kg x 60 gtt/ml

17 IV concepts Two concepts: 1. Flow rate: the rate at which IV fluid is given. 2. The drip factor: the number of drops per mL determined by the administration set.

18 Infusion = ml/hr Calculate the drip rate when the Physician Orders ml/hr using a 10 gtts/ml drip set 400 ml/hr x 10 gtts/ml 4000 gtts/hr ÷ 60 min/hr gtts/min ÷ 60 sec/min = 1 gtt/sec

19 Single Strength Dopamine Chart mcg/kg gtts

20 Using the Chart System 1. Estimate the patients weight in kg and round to nearest 10’s. 2. Multiply the (weight) x (order). 3. Use chart to add up drip rate. 4. Run IV at approximate rate or use an infusion pump.

21 Double Strength Dopamine Chart mcg/kg gtts

22 REMEMBER WANT = AMOUNT TO GIVE HAVE The WANT may get more complicated involving time or patient weight. The HAVE is in your possession and may change in concentration depending on service supplies.

23 Questions?