Presentation on theme: "Chapter 10: Intravenous Dosages"— Presentation transcript:
1 Chapter 10: Intravenous Dosages Math and Dosage Calculations for Health Care Third Edition Booth & WhaleyChapter 10: Intravenous DosagesMcGraw-Hill
2 Learning Outcomes10.1 Identify the components and concentrations of IV solutions Distinguish basic types of IV equipment Calculate IV flow rates for both electronically controlled and manually controlled IV devices Adjust the flow rate for IV infusions.
3 Learning Outcomes (cont.) 10.5 Calculate infusion time based on volume and flow rate Calculate volume based on infusion time and flow rate Reconstitute and calculate medication for intermittent IV infusions.
4 Results can be fatal if wrong medication or dosage is given. IntroductionIntravenous (IV) fluidsDelivered directly into the bloodstream via a veinIncludesSolutionsMedicationsBloodRapid effectResults can be fatal if wrong medication or dosage is given.
5 IV Solutions – FUNCTIONS ReplacementElectrolytesFluidsMaintenanceFluid balanceElectrolyte balanceKVO fluidsKeep Vein OpenMaintain an IV lineTherapeutic – Delivers medication to patient
6 IV Solutions – IV LABELS Solution labelsName of componentsThe exact amount of components
7 IV Solutions – IV LABELS (cont.) Rule 10-1 In abbreviations for IV solutions: Letters identify components Numbers identify concentration
8 IV Solutions – IV LABELS (cont.) Example5% dextrose in Lactated Ringer’s solution might be abbreviated in any of the following ways:D5LR5% D/LRD5%LR
9 IV Solutions – COMMONLY USED ABBREVIATIONS D10W10% dextrose in waterD5W5% dextrose in waterW; H2OWaterNS; NSSNormal saline (0.9% NaCl)LRLactated ringer’sRLRinger’s lactate
10 IV Solutions – COMMONLY USED ABBREVIATIONS (cont.) ½ NS; ½ NSSOne-half normal saline solution (0.45% NaCl)1/3 NS; 1/3 NSSOne-third normal saline solution (0.3% NaCl)¼ NS; ¼ NSSOne-fourth normal saline solution (0.225% NaCl)
11 IV Solutions – IV CONCENTRATIONS 5% Dextrose – contains 5 g of dextrose per 100 mLNormal saline0.9% salineContains 900 mg, or 0.9 g, of sodium chloride per 100 mL.½ Normal saline0.45% salineContains 450 mg, or 0.45 g, of sodium chloride per 100 mL
12 IV Solutions – IV CONCENTRATIONS (cont.) Choice of solution is based on patient requirementsIsotonic IV solutionsDo not affect fluid balance of cells and tissuesD5W, NS, LR
13 IV Solutions – IV CONCENTRATIONS (cont.) Hypotonic IV solutionsMove fluid into surrounding cells and tissuesRestore proper fluid level in cells and tissuesUsed to correct dehydration0.45% NS, 0.3% NS
14 IV Solutions – IV CONCENTRATIONS (cont.) Hypertonic IV solutionsDraw fluid from cells and tissues into blood streamUsed to correct severe fluid shifts (burns)3% Saline
15 IV Solutions – IV CONCENTRATIONS (cont.) Rule 10-2Patients 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.
16 IV Solutions – COMPATIBILITY AdditivesMedications, electrolytes, and nutrientsIf not prepackaged, will have to mix.
17 IV Solutions – COMPATIBILITY (cont.) Rule 10-3 Before combining any medications, electrolytes, or nutrients with an IV solution, be sure the components are compatible.
18 IV Solutions – COMPATIBILITY (cont.) Examples of incompatible medications/solutionsAmpicillinD5WCefotaxime sodiumSodium bicarbonateDiazepamPotassium chlorideDopamine HClPenicillinHeparinVitamin B complexLactated Ringer’sTetracyclineCalcium chloride
19 IV Equipment Primary Line Bag or bottle of IV solution – 500 mL or 1000 mLTubingDrip chamberClamp – regulate IVInjection portsAdd medication or compatible fluidAttach a second line
21 IV Equipment (cont.) Tubing Macrodrip Microdrip Larger drops in drip chamberInfusion rates of 80 mL/h or moreMicrodripSmaller drops in drip chamberInfusion rates less than 80 mL/h and KVOPediatric and critical care IV’s
22 IV Equipment – MONITORING ManuallyHang the bag hung 36 inches above patient’s heartAdjust flow rate using roller or screw clampsUsually adjusted in gtt/min
23 IV Equipment –MONITORING (cont.) Electronic devicesRate controllersGravityPincher maintains flow rateAlarm sounds when preset flow rate is not maintained
24 IV Equipment – MONITORING (cont.) Infusion pumpsApply pressure to deliver set volume per minuteSensor /alarmImproper rateEmpty bagMust monitor site for infiltration
25 IV Equipment – MONITORING (cont.) Syringe pumpsSyringe is inserted into pumpIncompatible medications or fluidsPediatric dosesProvide precise control over rate
26 IV Equipment – MONITORING (cont.) Patient-Controlled Analgesia (PCA) DevicePatient controls medication within preset limits per physician’s orderRecords number of times button is pushedUsed to monitor effectiveness of pain relief prescription
27 IV Equipment – MONITORING (cont.) Volume control setsImprove accuracy ofManual IV setupsElectronic rate controllersSmall volumes of fluids or medicationsUses: pediatric or critical care IVsExamples: Buretrol, Soluset, and Volutrol
28 Peripheral and Central IV Therapy Peripheral IV TherapyAccesses the circulatory system through a peripheral veinHand, forearm, foot, legScalp vein in infants
29 Peripheral and Central IV Therapy (cont.) Central line provides direct access to major veinsUsed when patient needs:Large amounts of fluidsA rapid infusion of medicationInfusion of highly concentrated solutionsLong-term IV therapy
30 Peripheral and Central IV Therapy (cont.) PICC – peripherally inserted central catheterInserted into arm vein and threaded into a central veinPort-A-CathSurgically placed under the skin for access to central veinAccessed through the skinFor intermittent use
31 Peripheral and Central IV Therapy (cont.) Rule 10-4 Never flush a sluggish IV with a syringe.May push a clot into the circulatory system
32 Peripheral and Central IV Therapy (cont.) Pain or swelling at the siteInfiltrationNeedle or catheter becomes dislodged from the veinFluid infuses into the surrounding tissuesSignsSwellingDiscomfortCoolness at the infiltration siteSizeable decrease in flow rate
33 Peripheral and Central IV Therapy (cont.) PhlebitisInflammation of the veinCausesIrritation by IV additivesMovement of needle or catheterLong-term IV therapySigns / SymptomsPain at or near siteHeatRednessSwelling at site
34 Peripheral and Central IV Therapy (cont.) Treatment of infiltration or phlebitisStop IV infusionRestart in a different site
35 PracticeMatching:Isotonic Hypotonic Hypertonic Central line Phlebitis Infiltration PCA Macrodrip MicrodripD60 gtt/mLPatient controls medicationFluid infuses into tissuesFor normal electrolyte levelsPICCFor high electrolyte levels15 gtt/minInflammation of a veinFor low electrolyte levelsFIEHCBGA
36 Calculating Flow Rates Flow rate - how fast the IV infusesCalculated fromAmount of fluid to be infusedLength of time for infusionExpressed as milliliters per hourmL/h
37 Calculating Flow Rates (cont.) Rule To calculate flow rates in milliliters per hour, identify the following:V (volume) – expressed in millilitersT (time) – expressed in hours (convert units as necessary)F (flow rate) – rounded to nearest tenthUse the formula method with or dimensional analysis to determine the flow rate in milliliters per hour.
38 Calculating Flow Rates (cont.) Find the flow rateOrdered: 500 mg ampicillin in 100 mL NS to infuse over 30 minutesConvert minutes to hour: 30 ÷ 60 = 0.5 hrFlow rate = 200 mL/hrExample
40 Calculating Flow Rates (cont.) Rule 10-6 To determine the flow rate (f) in drops per minute:1. Change the flow rate mL/h (F) to gtt/min (f) using the formula:F = flow rate; mL/hrC = calibration factor of tubing; gtts/mL60 = number of minutes in 1 hour2. Round to nearest whole number.
41 Calculating Flow Rates (cont.) ExampleFind the flow rate in drops per minute that is equal to 35 mL/hour using 60 gtt/mL microdrop tubing. f = 35 gtt/min
42 Calculating Flow Rates (cont.) Counting drops is not preciseCheck IV hourly to see if it is on scheduleBefore adjusting the rate, check facility policy
43 Calculating Flow Rates (cont.) Rule 10–7 To adjust the flow rate:Recalculate the infusion using the volume remaining in the IV and the time remaining in the order.Check the guidelines at your facility before adjusting the flow rate.
44 Calculating Flow Rates (cont.) ExampleOriginal Order: 1500 mL NS over 12 hours The IV was infusing at an original rate of 42 gtt/min using 20 gtt/mL macrodrip tubing. After 3 hours, 1200 mL remain in the bag. Flow rate adjustments must not exceed 25%.
45 Calculating Flow Rates (cont.) Example (cont.)Use formulaf = 44 gtt/min25% of original rate of 42 gtt/mL = 10.5Rate can be adjusted up or down within a range of 32.5 to 52.5 gtt/min.Rate can be adjusted to 44 gtt/min.
46 PracticeCalculate flow rate then determine if an adjustment is necessary. Adjustment cannot exceed 25%. Ordered: 250 mL NS over 2 hours (10 gtt/mL tubing) After 30 minutes 100 mL infused.
47 Practice Answer 25% of 21 = 5.25 Adjustment range = 15.75 to 26.75 You may adjust this infusion.Original drop ratef = 21 gtt/minAdjusted ratef = 17 gtt/min
48 Infusion Time and Volume If not specified in the order you may have to calculateDuration – if fluid volume and flow rate is knownFluid volume – if the duration and flow rate is known
49 Infusion Time and Volume (cont.) Rule To calculate infusion time in hours (T), identify the:V (volume) expressed in millilitersF (flow rate) expressed in milliliters per hourFractional hours by multiplying by 60Use this formula or dimensional analysis to find T, the infusion time in hours.
50 Infusion Time and Volume (cont.) ExampleFind the total time to infuse. Ordered: 1000 mL NS to infuse at a rate of 75 mL/h T = 13.3 Total time to infuse the solution = 13 hours and 20 minutes
51 Infusion Time and Volume (cont.) ExampleFind the total time to infuse. Ordered: 750 mL LR to infuse at a rate of 125 mL/hr started at 11 p.m. T = 6 The total time to infuse is 6 hours.
52 Infusion Time and Volume (cont.) Rule 10-9 To calculate the time when an infusion will be completed,You must know:1. The time the infusion started in military time2. The total time in hours and minutes to infuse the solution ordered
53 Infusion Time and Volume (cont.) Rule 10-9 (cont.)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.
54 Infusion Time and Volume (cont.) ExampleDetermine when the infusion will be completed. Ordered: 750 mL LR to infuse at a rate of 125 mL/hr and was started at 11 p.m. on 08/04/08 Infusion time = 6 hours 11 p.m. = 2300 hrs hours = 0500 or 5:00 a.m. on 08/05/08
55 Infusion Time and Volume (cont.) Rule To calculate infusion volume:Use the formula V = T x F or dimensional analysis to find V the infusion volume in mL.T (time) must be expressed in hoursF (flow rate) must be expressed in milliliters per hour
56 Infusion Time and Volume (cont.) ExampleFind the total volume infused in 5 hours if the infusion rate is 35 mL/h. V = 5 h × 35 mL/h V = 175 mL 175 mL will infuse in 5 hours
57 Infusion Time and Volume (cont.) ExampleFind the total volume infused in 12 hours if the infusion rate is 200 mL/h. V = 12 h × 200 mL/h V = 2400 mL 2400 mL will infuse in 12 hours
58 Intermittent IV Infusions IV medications may be administered intermittently with or without continuous IV therapy.Delivered throughIV secondary lineSalineHeparin lock
59 Intermittent IV Infusions – SECONDARY LINES “Piggyback” or IVPBIV setup attaches to a primary lineInfuse medications or other compatible fluids on an intermittent basisIVPB bags are smaller: 50, 100, or 150 mL
60 Intermittent IV Infusions – INTERMITTENT PERIPHERAL INFUSION DEVICES Saline or heparin locksAn infusion port attached to an already inserted IV needle or catheter.Allow direct injection of medication or infusion of IV medications.
61 Intermittent IV Infusions – INTERMITTENT PERIPHERAL INFUSION DEVICES (cont.) No continuous flow of fluidsRequires flushing 2 to 3 times per daySaline lock – uses saline as the flushHeparin lock – uses heparin, an anticoagulant, as the flush
62 Intermittent IV Infusions (cont.) Preparing and Calculating Intermittent InfusionsFlow rate is calculated the same as regular IV infusions.Amount of fluid may be less and time to infuse may be less than an hour.To calculate the flow rate you will need to change the number of minutes into hours.
63 Intermittent IV Infusions (cont.) Rule When preparing medication for an intermittent IV infusion:Reconstitute the medication using the label and package insert.Calculate amount to administer and the flow rate.
64 Intermittent IV Infusions (cont.) ExampleOrdered: Eloxatin 75 mg in 250 mL D5W IV piggyback over 90 minutes Reconstitute with 20 mL of water for injection. Dosage strength – see label Calculate the amount to administer and the flow rate.
65 Intermittent IV Infusions (cont.) Example (cont.)Amount to administer Flow rate using 15 mL mL A = 15 mL F = 177 mL/h65
66 PracticeFind total infusion time: Ordered: 650 mL 0.45 NS at 40 mL/h started at /09/08 T = hours Total infusion time = 16 hr 15 min When will this IV be completed? 7:30 p.m. 08/09/08
67 Practice Find the volume to administer: Ordered: D5NS at 65 mL/hr for 8 hoursV = 8 h x 65 mL/h V = 520 mLOrdered: NS at 100mL/h for 45 minV = 0.75 h x 100 mL/h V = 75 mL
68 Apply Your Knowledge Identify four functions of IV fluids. ANSWERS ReplacementMaintenanceKVOTherapeutic
69 Apply Your KnowledgeHow many mg of sodium chloride is in 100 mL of normal saline?How many mg of sodium chloride is in 100 mL of 0.45% NS?ANSWER mg NaClANSWER mg NaCl
70 Apply Your KnowledgeWhen you adjust the IV flow rate, what percentage of the original flow rate should you not exceed? Flushing a sluggish IV will not cause harm. True / FalseANSWER 25%Flushing may push a clot into the circulatory system causing an obstruction.
71 End of Chapter 10 Wisdom consists of the anticipation of consequences. ~ Norman Cousins