2. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved Math for the Pharmacy Technician: Concepts and Calculations Chapter 8: Intravenous Calculations Egler Booth

3. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-2 Intravenous Calculations

4. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-3 Learning Objectives  Identify the components and concentrations of IV solutions.  Calculate IV flow rates.  Calculate infusion time based on volume and flow rate. When you have successfully completed Chapter 8, you will have mastered skills to be able to:

5. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-4 Learning Objectives (con’t )  Calculate infusion completion time based on flow rate.  Calculate volume based on infusion time and flow rate.  Calculate medications for intermittent IV infusions.

6. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-5Introduction  Intravenous (IV) fluids are solutions including medication that are delivered directly into the bloodstream via a vein  Blood is also delivered by IV  IV fluids have a rapid effect  Are necessary during emergencies or other critical care situations

7. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-6  Replacement fluids  Maintenance fluids  KVO (Keep Vein Open) fluids  Therapeutic fluids IV Solutions-Functions

8. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-7 IV Replacement Fluids  Replace electrolytes and fluids lost due to hemorrhage, vomiting, or diarrheaExamples:  Whole blood  Nutrient solutions  Fluids to treat dehydration

9. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-8 IV Maintenance Fluids  Maintain normal electrolyte and fluid balanceExample: – Normal saline given during and after surgery

10. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-9 IV KVO Fluids  To keep the vein open (KVO or TKO)Example:  5% dextrose in water

11. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-10 Therapeutic Fluids Deliver medication to the patient

12. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-11 IV Labels  Solutions are labeled with  The name of the components  The exact amount of the components

13. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-12 IV Labels IV Labels (con’t)  In abbreviations for IV solutions:  Letters identify the component  Numbers identify the concentration

14. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-13 IV Labels IV Labels (con’t) Example:  An order for 5% dextrose in Lactated Ringer’s solution might be abbreviated in any of the following ways:  D5LR  5% D/LR  D5%LR

15. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-14 Common Abbreviations D W, H 2 0 S NS, NSS RL LR NS Dextrose Water Saline Normal Saline Lactated Ringer’s Ringer’s Lactate Half Normal Saline Solution (0.45% NaCl) (0.9% NaCl)

16. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-15 IV Concentrations  5% Dextrose It contains 5 g of dextrose per 100 mL.  Normal saline is 0.9% saline It contains 900 mg, or 0.9 g, of sodium chloride per 100 mL.  ½ Normal saline is 0.45% saline It contains 450 mg, or 0.45 g, of sodium chloride per 100 mL.

17. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-16 IV Concentrations (con’t)  Isotonic  They have no effect on the fluid balance of the surrounding cells or tissues. Examples: Examples: D5W, NS, LR  Fluid moves across the cell membrane into surrounding cells and tissues.  This movement restores the proper fluid level in cells and tissues of patients who are dehydrated. Examples: Examples: 0.45% NS, 0.33% NaCI  Hypotonic

18. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-17  Hypertonic IV Concentrations IV Concentrations (con’t)  These solutions draw fluids from cells and tissues across the cell membrane into the bloodstream.  They are helpful for patients with severe fluid shifts such as those caused by burns. Example: Example: 3% saline

19. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-18 IV Concentrations IV Concentrations (con’t) Patients with normal electrolyte levels are likely to receive isotonic solutions.  Patients with high electrolyte levels will receive hypotonic solutions.  Patients with low electrolyte levels will receive hypertonic solutions.

20. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-19Compatibility  Additives  Medications, electrolytes, and nutrients combined with IV solutions  Common additives: potassium chloride, vitamins B and C, and antibiotics  Come prepackaged in the solution or may need to be mixed

21. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-20 Compatibility Compatibility (con’t) Before combining any medications, electrolytes, or nutrients with an IV solution, be sure the components are compatible.

22. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-21 Incompatible Combinations Examples  Ampicillin + 5% dextrose in water  Cefotaxime sodium + Sodium bicarbonate  Diazepam + Potassium chloride  Dopamine HCl + Sodium bicarbonate  Penicillin + Heparin  Penicillin + Vitamin B complex  Sodium bicarbonate + Lactated Ringer’s  Tetracycline HCl + Calcium chloride

23. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-22 Calculating Flow Rates To calculate flow rates in milliliter per hour, identify the following: Use the formula method or dimensional analysis to determine the flow rate in milliliters per hour. V V (volume) is expressed in milliliters T T (time) must be expressed in hours (convert the units when necessary using calculation methods) F F (flow rate) will be rounded to the nearest tenth

24. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-23 Review and Practice Flow rate = 200 mL/h Find the flow rate. Ordered: 500 mg ampicillin in 100 mL NS to infuse over 30 minutes

25. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-24 Calculating Flow Rates for Manual Regulation To determine the flow rate (f) in drops per minute: 1.Change the flow rate mL/h (F) to gtt(drops)/min (f) using the formula where F = the flow rate in milliliters/hour C = the calibration factor of the tubing in drops per mL 60 = number of minutes in an hour

26. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-25 Review and Practice Flow rate = 35 gtt/min Find the flow rate in drops per minute that is equal to 35 mL/hour using 60 gtt (Drops) /mL microdrop tubing.

27. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-26 Infusion Time and Volume  An order may call for a certain amount of fluid to infuse at a specific rate without specifying the duration.  You will need to calculate the duration or amount of time the IV will take to infuse.  You may know the duration and flow rate and will have to calculate the fluid volume.

28. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-27 Calculating Infusion Time (T), To calculate infusion time in hours (T), identify the: V V (volume) expressed in milliliters F F (flow rate) expressed in milliliters per hour Fractional hours by multiplying by 60 Use this formula or dimensional analysis to find T, the infusion time in hours.

29. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-28 Review and Practice Total time to infuse the solution is 13 hours and 20 minutes Find the total time to infuse. Ordered: 1000 mL NS to infuse at a rate of 75 mL/h

30. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-29 Review and Practice T = 6 hours = total time to infuse the 750 mL Find the total time to infuse. Ordered: 750 mL LR to infuse at a rate of 125 mL/hr started at 11 p.m.

31. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-30 Calculating Infusion Completion Time To calculate the time when an infusion will be completed, you must first know the time the infusion started in military time and the total time in hours and minutes to infuse the solution ordered.

32. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-31 Calculating Infusion Completion Time (con’t) Since each day is only 24 hours long, when the sum is greater than 2400 (midnight), you must start a new day by subtracting 2400. This will determine the time of completion, which will be the next calendar day.

33. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-32 Review and Practice The infusion will be complete at 0500 or 5:00 a.m. on 08/05/05 Determine when the infusion will be completed. Ordered: 750 mL LR to infuse at a rate of 125 mL/hr, started at 11 p.m. on 08/04/05

34. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-33 Calculating Infusion Volume Use the formula V = T X F or dimensional analysis to find V the infusion volume in mL, where the  T  T (time) must be expressed in hours  F  F (flow rate) must be expressed in milliliters per hour

35. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-34 Review and Practice V=175 mL or the volume that will infuse over 5 hours Find the total volume infused in 5 hours if the infusion rate is 35 mL/h.

36. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-35 Review and Practice V = 2400 mL = the volume that will infuse over 12 hours Find the total volume infused in 12 hours if the infusion rate is 200 mL/h.

37. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-36 Intermittent IV Infusion  IV medications are sometimes delivered on an intermittent basis  Delivered through IV secondary line Saline Heparin lock  Can be delivered with continuous IV therapy or when no continuous IV solutions are infusing

38. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-37 Secondary Lines (Piggybacks or IVPB)  IV setup that attaches to a primary line  Used to infuse medications or other compatible fluids on an intermittent basis (such as q6h)  Uses shorter tubing  IVPB bags are smaller: 50,100, or 150 mL

39. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-38 Intermittent Peripheral Infusion Devices  Saline or heparin locks  An infusion port attached to an already inserted IV needle or catheter  Allow direct injection of medication or infusion of IV medications  Medications ordered as IV push or bolus

40. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-39 Intermittent Peripheral Infusion Devices (con’t)  Since there is no continuous flow of fluids through the IV line you must flush the device 2 to 3 times per day to prevent blockage.  Saline lock -- is an infusion port attached to an already inserted catheter for IV access, flushed with saline.  Heparin lock -- is an infusion port attached to an already inserted catheter for IV access, flushed with heparin.

41. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-40 Preparing and Calculating Intermittent Infusions  Flow rate is calculated for prepared medications the same as regular IV infusions.  Amount of fluid may be less and time to infuse may be less than an hour.  Calculate the flow rate you will need to change the number of minutes into hours.

42. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-41 Preparing and Calculating Intermittent Infusions (con’t) When preparing medications for an intermittent IV infusion:  Reconstitute the medication using the label and package insert.  Calculate amount to administer and the flow rate.

43. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-42  Identify four functions of IV fluids. Review and Practice Answers: 1. Replacement 2. Maintenance 3. KVO 4. Therapeutic

44. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-43  How many mg of sodium chloride is in 100 mL of normal saline? Review and Practice Answer: 900 mg NaCl  How many mg of sodium chloride is in 100 mL of 0.45% NS? Answer: 450 mg NaCl

45. McGraw-Hill ©2010 by the McGraw-Hill Companies, Inc All Rights Reserved 8-44 Intravenous Calculations THE END As a pharmacy technician you will need to know how to perform accurate IV calculations. Results can be fatal if the wrong medication or dosage is given