Intravenous Calculations Copyright 2007 by Mosby Inc All

What is Intravenous Therapy l Used to administer fluids containing water, dextrose, vitamins, electrolytes, and drugs l Administered IV for direct absorption & fast action IV push or bolus l Drugs diluted to reduce irritation to the vein l l Nursing function & responsibility of drug preparation: l l Know IV set & drip factor Calculating IV flow rate Gather proper equipment Know the drug & expected & unexpected reactions Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc. 2

Objectives Calculating drops per minute (gtt/min) when given the total volume and time over which an IV solution or intravenous piggyback is to be infused l Calculating milliliters per hour (ml/h) when given the total volume and time over which an IV solution or intravenous piggyback is to be infused l Copyright © 2007 by Mosby, Inc. All rights reserved. 3

Intravenous Infusion Set Includes: l Sealed bottle or bag l Tubing • • • Drip chamber connected by small tube or spike Tubing leading from drip chamber to needle or catheter Clamp to adjust flow rate Copyright © 2007 by Mosby, Inc. All rights reserved. 4

Intravenous Infusion Set (cont’d) FIGURE 16 -1 Intravenous infusion sets. (Modified from Clayton BD, Stock YN: Basic pharmacology for nurses, ed 13, St Louis, 2004, Mosby. ) Copyright © 2007 by Mosby, Inc. All rights reserved. 5

Two Methods for Administering IV Fluids & Drugs l Continuous IV infusion l l Replaces lost fluid, maintains fluid balance, & serves as a vehicle for drug administration Intermittent IV infusion l Used primarily to give IV drugs Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc. 6

Continuous IV Administration l HCP orders the type & amount of solution in liters over a 24 hour period l l Nurse calculates the drop factor, the amount of fluids to be administered, & time period IV sets l Drop factor is the number of drops per milliliter as is normally printed on the packaging cover of the set l l Macrodrip delivers a large drops per ml (10 -20 gtt/ml) Microdrip or minidrip delivers small drops per ml (60 gtt/ml) Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc. . 7

Regulating IV Flow Rates Regulation is the responsibility of the nurse. l Irregular rates lead to complications. l Sometimes the rate must be adjusted. l Copyright © 2007 by Mosby, Inc. All rights reserved. 8

Adjusting Flow Rates FIGURE 16 -3 Count drops per minute by watching the drip chamber for 1 minute and adjusting the roller clamp as needed to deliver the desired number of drops per minute. (From Potter PA, Perry AG: Fundamentals of nursing, ed 6, St Louis, 2005, Mosby. ) Copyright © 2007 by Mosby, Inc. All rights reserved. 9

Continuous IV Administration l l l For IV rates at 100 ml/hr or more, macrodrip is generally used For IV rates < 100 ml/hr, or client is a child, the microdrip set is preferred Keep Vein Open (KVO) or to Keep Vein Open (TKO)- fluids given at a slow rate; generally ordered to maintain an open, functioning, IV line in case of emergency situation l For KVO. A microdrip set (60 gtt/ml) & IV bag of 250 ml Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc. . 10

Gravity Infusion Calculation Formula Copyright © 2007 by Mosby, Inc. All rights reserved. 11

Calculating IV Flow Rate Three-step method 1. 2. Amount of solution Hours to administer Milliliters per hour 60 minutes = milliliters/hour (ml/h) = milliliters/min (ml/min) 3. Milliliters per minute X drops per milliliter of IV set = drops/minute (gtt/min) Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc. . . 12

Calculating IV Flow Rate Two-step method 1. Amount of fluid = milliliters per hour (ml/h) Hours to be Adm. 2. Milliliters per hour X Drops per milliliter (IV set) = drops/min (gtt/min) 60 minutes ****If the milliliters per hour is known, use step 2 to determine drops per minute One-step method 1. Amount of fluid X drops per milliliter (IV set) = drops/min (gtt/min) Hours to administer X Minutes per hour (60) Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc. . 13

Intravenous Flow Rate Example: Amount of fluid ÷ hours to administer = ml/hr × gtt/ml (IV set) = gtt/min 60 minutes Order: 1000 ml of 5% DW with. 45% Na. Cl, q 8 h IV set: 10 gtt/ml (macrodrip) 1000 ml ÷ 8 hours = 125 ml/hr 1 125 ml x 10 gtt/ml = 125 = 20. 8 or 21 gtt/minute 60 minutes 6 6 Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc. . 14

Intermittent Intravenous Administration Amount of solution × gtt/ml (IV set) = gtt/min minutes to administer Order: ticarcillin (Ticar) 500 mg, IV, q 6 h Available: Ticar 1 g (add 4 ml of diluent) Set and solution: calibrated cylinder, drop factor: 60 gtt/m. L Instruction: dilute drug in 75 m. L of D 5 W and infuse over 40 minutes. 3 75 ml × 60 gtt/ml = 225 = 112. 5 or 113 gtt/min 40 min to admin 2 2 Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc. . 15

Intermittent IV Administration l Medications may be prescribed to be administered three to six times a day in small volumes (50 to 100 ml) l l Drug is usually infused over 15 min to 1 hour Separate tubing for drug, secondary tubing, is inserted into the primary IV line set or continuous IV set Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.

A client is to receive a 100 ml of a fluid bolus over 2 hours. The drip factor for the IV set is 15 gtt/cc. At what rate should this bolus be administered? 1. 2. 3. 4. 12. 5 gtt/min 25 gtt/min 30 gtt/min 50 gtt/min Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc. 17

Secondary IV Sets without IV Pump l l Calibrated cylinder (Buretrol, Volutrol, Soluset)- chamber holds 150 ml of solution; used for injecting medication into chamber & diluted with solution Secondary IV set-used to infuse small volumes (50, 100, 250 ml & for children’s IV solution) l Both methods are considered IV piggyback (IVPB) Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc. . 18

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IV Pump Infusion Formula Copyright © 2007 by Mosby, Inc. All rights reserved. 20

Infusion of IV Fluids with an IV Pump Example: Infuse 750 ml of lactated Ringer’s solution (LR) over 8 hours. How many milliliters per hour should the IV pump be programmed to deliver? Copyright © 2007 by Mosby, Inc. All rights reserved. 21

Infusion of IV Medications with an IV Pump Example: Administer 1. 5 g of Vancomycin over 90 minutes. The Vancomycin is dissolved in 200 m. L of D 5 W. How many milliliters per hour should the IV pump be programmed to deliver? Copyright © 2007 by Mosby, Inc. All rights reserved. 22

Intermittent infusion Adapters/Devices l l Intermittent drug therapy requires an adapter attached to the IV catheter or needle where the IV tubing was disconnected Adapters have ports (stoppers 0 where needles, needless, or IV tubing can be inserted as needed for drug therapy Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc 23

Infusion Pump Rate Amount of solution ÷ minutes to admin = ml/hr 60 min/hr Order: ticarcillin (Ticar) 500 mg, IV, q 6 h Available: Ticar 1 g (add 4 ml of diluent) Infusion pump Dilute drug in 100 ml of D 5 W; infuse over 45 minutes. 100 ml ÷ 45 min to admin = (invert the divisor and multiply) 60 min/hr 4 100 ml × 60 = 400 = 133 ml/hr (infusion rate) 45 3 3 Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc 25

Direct Intravenous Injections l Medications given by the IV injection route are called IV push medications l Preferred route for clients with poor muscle mass or decreased circulation or if the drug is poorly absorbed by body tissue Rapid onset of medication l Calculation errors can have a serious, even fatal outcomes l Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc 26

Electronic Intravenous Regulators l l Pumps used to deliver a prescribed rate of IV solution Two types: Volumetric regulator- delivers a specific volume of fluid at a specific rate, in ml/hour l Nonvolumetric regulator-designed to infuse at a drop rate in gtts/min l Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc 27

Calculating Flow Rates for IV Drugs l IV drug infusion rates depend on drug dosing instructions l l Amount of dilution & length of infusion time Nurse must calculate first the dose from HCP then calculate the flow rate Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc 29

Secondary Sets l Find drops per minute, use calibrated cylinder (Buretrol) Amount of Solution X Drops per milliliter of the set = Drops/min (gtt/min) Minutes to administer Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc 30

Volumetric Regulators l Find milliliters per hour (Infusion Rate) Amount of solution: Minutes to administer 60 min/hr = Milliliters/hour (ml/hr) Elsevier items and derived items © 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc 31