Advanced IV-Metrology F090

ADVANCED IV METROLOGYSelf-Learning Module

TOPIC PAGE

IV Flow Rates (review) 2-5

Timing IV Push Medications 5-7

Continuous Medicated IV Infusions 8-10

Titrating Heparin Infusions 10-12

Advanced/Critical Care Infusions 12-14

Pediatric Doses (pp 14-16, #’s1-10 for review) 14-16

Answer Key 17

Spring 2010

ADVANCED IV METROLOGY

CALCULATING IV FLOW RATES – ML/HR

Electronically Regulated Flow Rates are calculated in ml/hr. The nurse programs the infusion device to deliver the ordered solution in milliliters per hour (ml/hr)

Formula for calculating ml/hr:

TV (ml) = ml/hr OR TV (ml) X 60 (min) = ml/hr TT (hr) TT (min)

TV = total VOLUME to be infused in mlTT = total TIME of infusion

EXAMPLES 1. Infuse 250ml over 2 hours

250ml = 125ml/hr 2hr

2. Infuse 2L over 4 hours

2000ml = 500ml/hr 4hr

*3. Infuse 75ml in 30 minutes (IVPB)

75ml X 60 = 150ml/hr 30min

*4. Infuse 100ml in 20 minutes (IVPB)

100ml X 60 = 300ml/hr20min

*IVPBs (often < 1 hr infusion)

PRACTICE PROBLEMS – Electronically Regulated Flow Rates

Calculate the IV flow rate in ml/hr for each of the following problems:

1. Infuse 1.5 liters of NS over 3 hours

*2. Unasyn 0.5gm in 75ml D5W IVPB to infuse over 20 minutes

*3. Zantac 50mg in 100ml NS to infuse over 30 minutes

4. Infuse 500ml LR over 2 hours

2

*5. Ancef 1gm in 100ml D5W IVPB to infuse in 45 minutes

6. Infuse 1200ml D51/2NS in 6 hours

7. Infuse 250ml packed red blood cells in 4 hours

8. Infuse 1 liter D5LR over 8 hours

*9. Carbenicillin disodium 2 g IVPB diluted in 50ml D5W to infuse in 15 minutes

*10. 50ml drug “X” to infuse in 20 minutes

CALCULATING IV FLOW RATES – DROPS/MINUTE (gtt/min)

Manually Regulated Flow Rates are calculated in drops/minute. The nurse calculates the number of drops the IV should flow per minute according to the ordered infusion time. The drip rate (gtt/min) is then set by adjusting the roller clamp and timed by counting the number of drops dripping per minute into the IV drip chamber.

The IV solution may be a continuous infusion or an intermittent/bolus infusion.

Formula for calculating gtt/min:

D X V = gtt/minM

D = DROP factor of tubing (gtt/ml)M = Time of infusion in MINUTESV = Total VOLUME to be infused in ml

EXAMPLES1. Order is to infuse D5NS at 125ml/hr. The drop factor is 15gtt/ml

15 X 125 = 31.25 or 31gtt/min 60

3

2. Order is to infuse LR at 150ml/hr. The drop factor is 10gtt/ml

10 X 150 = 25gtt/min 60

3. Infuse 1L NS over 4 hours. The drop factor is10gtt/ml

10 X 250 = 41.66 or 42gtt/min 60

4. Order is to infuse 200ml 0.9% NaCl over 2 hours. The drop factor is 20gtt/ml. 20 X 100 = 33.33 or 33gtt/min 60

*IVPBs (often < 1 hr infusion)*5. Order is for Clindamycin 600mg in 100ml D5W to infuse in 30 minutes. Drop factor is 20gtt/ml.

20 X 100 = 66.66 or 67gtt/min 30

*6. Order is to infuse IVPB “X” in 30 minutes. The bag contains 50ml; the drop factor is 10gtt/ml. 10 X 50 = 16.66 or 17gtt/min 30 PRACTICE PROBLEMS – Manually Regulated Flow RatesCalculate the IV flow rate in gtt/min for each of the following problems:

1. Infuse 1L NS bolus IV over 2 hours. Drop factor of tubing is 20gtt/ml.

2 Infuse 1000ml of lactated ringers IV in 6 hours with a 10gtt/ml administration set.

*3. Order is for Ancef 2gm IVPB diluted in 100ml D5W to infuse in 45 minutes. Drop factor of the tubing is 15gtt/cc

*4. Order is for Zosyn 3gm in 100ml D5W to be infused in 40 minutes. Drop factor is 10gtt/ml. How many drops/minutes do you infuse the IVPB?

4

*5. Order is for carbenicillin disodium 2gm IVPB diluted in 50ml D5W to infuse in 30 minutes. Drop factor is 60gtt/ml.

6. Order is for 800ml 5% glucose in water to infuse in 4 hours. Drop factor is 15gtt/ml.

7. Order is for D51/2NS with 20meqKCL/liter to infuse at 100ml/hr. Drop factor is 10gtt/ml.

*8. Order is for Unasyn 1.5gm in 100ml D5W IV to be infused in 20 minutes. Drop factor is 20gtt/ml.

*9. Keflin 750mg in 200ml NS is ordered to be infused in 45 minutes. Drop factor is 15gtt/ml.

10. Order is D5NS at 150ml/hr. Drop factor is 15gtt/ml.

Timing IV Push Medications

The direct IV push method of medication administration is used to give small amounts of diluted or undiluted medication over a brief period of time (seconds or minutes).

Before pushing any medications, verify safe dose limits, rates of flow, dilutions, compatible solutions and routes. Monitor patient response during and after administration.

Example: Order is for 80mg Lasix IV now. On hand is a 10mg/ml vial of Lasix. Drug reference states each 40mg of Lasix is to be given over 1 minute.

1. Calculate the volume of medication is to be given (ml):

Ratio Proportion Method

10mg : 1ml : : 80mg : Xml10X = 80 X = 8ml

Formula Method

80mg X 1ml = 8ml10mg

Dimensional Analysis Method

80mg X 1ml = 8ml 10mg

5

2. Calculate total time to administer medication, based on drug reference:


40mg : 1min : : 80mg : Xmin40X = 80 X = 2min

Formula Method

80mg X 1min = 2min40mg


80mg X 1min = 2min 40mg

2. Calculate administration time in ml/min: Think: TV(ml) ml/min TT(min)

8ml = 4ml/min2min

PRACTICE PROBLEMS – Timing IV Push Medications

1. Order is for Dilantin 100mg IV push now. On hand is Dilantin 250mg/5ml. Drug reference states to administer IV Dilantin no faster than 50mg/min.

How many ml do you give?

How many minutes will it take to give the Dilantin?

How many ml will you give each minute?

2. Order is for Morphine Sulfate 15mg IV push now. On hand is Morphine Sulfate 10mg/1ml. Drug reference states to give the medication no faster than 2.5mg/min.

How many ml Morphine do you give?

How many minutes will it take to give the Morphine?


6

3. Order is for Digoxin 0.25mg IV now. Available is an ampule of Digoxin 500mcg/2ml. The drug reference states to administer a single dose over 5 minutes.How many ml do you give?

How many minutes will it take to give the dose?


4. Order is for Valium 7.5mg IV now. Available is Valium 10mg/2ml. Drug reference states to administer each 5mg over 1 minute. How many ml of Valium will you give?



5. Order is for protamine sulfate 50 mg IV stat. Available is protamine sulfate 50mg/10ml. Rate of infusion is not to exceed 5mg/min. How many ml of protamine sulfate will you administer?


How fast will you push the medication (ml/min)?

7

CONTINUOUS MEDICATED IV INFUSIONS

Calculating Hourly IV Doses and Rates 1. Drug “on hand” or “available” is the concentration of the IV medication bag (1gm aminophylline

in 500ml D5W or 25,000units heparin in 500ml D5W) 2. “Dose desired” or what “doctor ordered” is the hourly dose (i.e., drug order is for 50mcg/hr,

25mg/hr; 2g/hr) OR the hourly rate (ml/hr) that is infusing3. Calculate hourly dose, if not already ordered this way4. Convert units of measure, as needed, to plug into math formula

EXAMPLES 1. Patient has 1gm Aminophylline in 500ml D5W hanging. The order is to infuse 40mg/hr. At what rate would you set the IV pump?


1000mg : 500ml : : 40mg : Xml1000X = 20,000 X = 20ml/hr

Formula Method

40mg X 500ml = 20ml/hr1000mg


40mg X 500ml = 20ml/hr1hr 1000mg

2. A Heparin drip is prepared by pharmacy and contains 20,000units heparin in 500ml 0.9%NaCl. The order is to infuse @ 1200units/hr. At what rate would you set the infusion pump?


20,000units : 500ml : : 1200units : Xml20,000X = 600,000 X = 30ml/hr

Formula Method

1200units X 500ml = 30ml/hr20,000units


1200units X 500ml = 30ml/hr1hr 20,000units

8

3. The Aminophylline drip contains 1g in 500ml D5W. The infusion pump is delivering 20ml/hr. How much Aminophylline is the patient receiving per hour?


1000mg : 500ml : : Xmg : 20ml500X = 20,000 X = 40mg/hr Formula Method

20ml X 1000mg = 40mg/hr500ml


20ml X 1000mg = 40mg/hr1hr 500ml

4. The Heparin drip contains 20,000U in 500ml 0.9% NaCl. The infusion pump is delivering 30ml/hr. How much Heparin is the patient receiving per hour?


20,000units : 500ml : : Xunits : 30ml500X = 600,000 X = 1200units/hr Formula Method

30ml X 20,000units = 1200units/hr500ml


30ml X 20,000units = 1200units/hr1hr 500mlPRACTICE PROBLEMS – Continuous Medicated IV Infusions

1. Patient has 20,000units of heparin in 500ml D5W hanging. The order is to infuse 1400units/hr. At what rate would you set the IV pump?

2. Order reads to mix 2gm Drug X with 500ml NS and infuse at 80mg/hr. At what rate do you set the pump?

3. Ordered is an Aminophylline drip at 30mg/hr. Infusion bag contains 1gm Aminophylline/500cc D5W. How fast is the infusion running/hr?

9

4. Order reads D51/2NS with 20mEq KCL/liter @ 150ml/hr. How much KCL is the patient receiving each hour?

5. The patient has a morphine drip for pain. The IV bag contains morphine 75mg/150ml. The Infusion is running at 6ml/hr. How much morphine is the patient receiving each hour?

6. The patient has a magnesium sulfate drip hanging. The bag contains MgSO4 40g/500ml LR. The IV is infusing at 13ml/hr. How much magnesium is the patient receiving each hour?

TITRATING A HEPARIN INFUSION

EXAMPLE Patient is to have a heparin drip. Order is to start the infusion at 18units/kg/hr. The patient weighs 198lbs. The pharmacy has prepared a bag with 20,000units of heparin in 500ml D5W. At what rate do you set the pump?

Calculate kg weight: 198 2.2 = 90Calculate hourly dose: (18)(90) = 1620units/hr Ratio Proportion Method

20,000units : 500ml : : 1620units : Xml20,000X = 810,000 X = 40.5ml/hr or 41ml/hr Formula Method

1620units X 500ml = 40.5ml/hr or 41ml/hr20,000U


1620units X 500ml = 40.5ml/hr or 41ml/hr1hr 20,000untis

10

PRACTICE PROBLEMS – Titrating a Heparin Infusion

1. Heparin Sliding Scale: PTT q 4 hours after start of heparin dripa. IV heparin infusion at 17units/kg/hr, rounded to nearest unitb. Adjust heparin to keep PTT 70-90 secondsc. If PTT 45-69, increase drip by 100units/hrd. If PTT 35-44, give 1000units heparin bolus, increase drip by 100 units/hre. If PTT < 35, give 2000units heparin bolus, increase drip by 200units/hrf. If PTT < 45, on two consecutive occasions, call physiciang. If PTT 95-100, reduce heparin drip by 100units/hrh. If PTT 111-119, stop heparin for one hour; restart at 100units/hr less than

previous ratei. If PTT > 120, call physician

The heparin solution is prepared in the pharmacy. The label reads 25,000units heparin in 500ml D5W. The patient weighs 132 lbs.

a. _______ Calculate the patient’s kg weight.

b. _______ Calculate the hourly dose of Heparin.

c. _______ After calculating the dose of heparin for this patient, at what rate do you set the pump to deliver the ordered dose?

d. _______ Four hours later, the PTT is 33. What action do you take? What is the new rate _______ per hour?

e. _______ Four hours later the PTT is 43. What action do you take? What is the new rate per_______ hour?

2. Heparin Sliding Scale: PTT q 4 hours after start of heparin dripa. IV heparin infusion at 18units/kg/hr, rounded to nearest unitb. Adjust heparin to keep PTT 70-90 secondsc. If PTT 45-69, increase drip by 100units/hrd. If PTT 35-44, give 1000units heparin bolus, increase drip by 100units/hre. If PTT < 35, give 2000units heparin bolus, increase drip by 200units/hrf. If PTT < 45, on two consecutive occasions, call physiciang. If PTT 95-100, reduce heparin drip by 100units/hrh. If PTT 111-119, stop heparin for one hour; restart at 100units/hr less than

previous ratei. If PTT > 120, call physician

The heparin solution is prepared in the pharmacy. The label reads 25,000units heparin in 250ml D5W. The patient weighs 143 lbs.

11

a. ________ Calculate the patient’s kg weight.

b. _______ Calculate the hourly dose of heparin.

c. ________ After calculating the dose of heparin for this patient, at what rate do you set the pump to deliver the ordered dose?

d. _______ Four hours later, the PTT is 42. What action do you take? What is the new rate/hr?_______

e. _______ Four hours later, the PTT is 60. What action do you take? What is the new rate/hr? _______

Advanced/Critical Care IV Infusions

EXAMPLES 1. Mr. Johnson is receiving a NTG drip at 25mcg/min. Concentration is 50mg NTG/250ml. At how many ml/hr will the IV infuse?

Calculate hourly dose = (25)(60) = 1500mcg/hr

Convert mcg to mg: 1500mcg = 1.5mg


50mg : 250ml : : 1.5mg : Xml50X = 375 X = 7.5 or 8ml/hr

Formula Method

1.5mg X 250ml = 7.5ml/hr or 8ml/hr50mg

12


1.5mg X 250ml = 7.5 or 8ml/hr1hr 50mg

2. Order is for Nipride (50mg/250ml) to infuse at 2mcg/kg/min. Pt weighs 154lbs.

Calculate kg weight: 154 2.2 = 70kgCalculate hourly dose: (2)(70)(60) = 8400mcg/hr Convert mcg to mg: 8400mcg = 8.4mg


50mg : 250ml : : 8.4mg : Xml50X = 2100 X = 42ml/hr

Formula Method

8.4mg X 250ml = 42ml/hr50mg


8.4mg X 250ml = 42ml/hr1hr 50mg

PRACTICE PROBLEMS – Advanced/Critical Care IV Infusions

1. _____ Isuprel, add 1mg to 500ml of IV fluid and run at 7mcg/min. How fast will the IV run?

2. _____ Available is 10units Pitocin in 1000cc LR. Ordered infusion is 1mu/min. How many ml are ordered per hour? Remember 1unit = 1000milliunits (mu)

3. _____ Order is for Nipride 50mg/250cc. Infuse at 5mcg/kg/min (patient weight is 110lbs). How many ml/hr will this be?

4. ______ A standard dopamine drip, 800mg/500ml D5W, is available. The order is to deliver 10mcg/kg/min. The patient weighs 80kg. At what rate will you set the pump?

13

5. ______ A patient will undergo a labor induction with Pitocin. Available is 10units Pitocin in 1000ml LR. Ordered infusion is 3mu/min. How many ml are ordered per hour

6. ______ Levophed, add 4mg to 500ml. Infuse at 6mcg/min. At what rate ml/hr will this IV run?

7. _______ The order is for Esmolol 100mcg/kg/min. The bag is mixed with 5g Esmolol/500ml of D5LR. The patient weighs 143 pounds. How fast should the IV be running?

8. _______ The pharmacy prepares a Lidocaine drip with 2g Lidocaine/250ml D5W. The orders are to infuse the Lidocaine at 3mg/min. At what rate do you set the IV pump?

CALCULATING PEDIATRIC SAFE DOSE RANGES

Convert Weight from Pounds to Kilograms

Example: total weight is 12 lbs 8 oz

1. Convert ounces to pounds by dividing ounces by 16

8 oz 16 oz = 0.5 lb

2. Divide total pounds (to the nearest hundreth) by 2.2

Total pounds = 12 lbs + 0.5 lbs = 12.5 lbs

12.5 2.2 = 5.681 or 5.68 kg

Calculate Safe Dose Ranges (SDR)

Example: SDR is 30-100mg/kg/day in four divided doses Ordered dose is 150mg q 6hr

1. low range calculation: 5.68 x 30mg = 170.4 = 170mg/dayhigh range calculation: 5.68 x 100mg = 568mg/day

SDR = 170-568 mg/day

2. evaluate appropriateness of ordered dose:150mg x 4 doses/day = 600mg/day

3. decision: ordered dose is not within SDR, hold and clarify

14

Convert the following weights from pounds to kilograms:

1. _____ 8lb 3. _____ 4lb, 6oz

2. _____ 5lb, 8oz 4. _____ 18lb, 9oz

5. Weight = 25lbs, 6ozSDR reference: 10-30mg/kg/day in 3 divided dosesOrder is for 100mg q 8hrs; is this a safe dose?

6. Weight = 33lbSDR reference: 100-200mcg/kg/day in 4 divided dosesOrder is for 0.9mg q6hrs; is this a safe dose?

7a)_______ The order is for Ampicillin 700mg IV q12 hrs b)_______ Reference: Ampicillin 150-200mg/kg/day. Child weighs 17lbs 7oz.

a) What is the safe dose range for this child?

b) Available is Ampicillin 1g. Instructions for reconstitution state to add2.6ml sterile water for a yielding concentration of 250mg/ml. How many ml of the reconstituted medication would you draw up?

8a)_______ The order is for Rocephin 600mg IV QD b)_______ Reference: Rocephin 50-75mg/kg/24hrs, not to exceed 2g/day. Child weighs 18lbs 9oz.

a. What is the safe dose range of the drug for this child?

b. On hand you have Rocephin 1g. Instructions state to dilute with 2.3ml of sterile water for a total volume of 1g/2.8ml. How many ml of the reconstituted medication will you draw up?

15

9a)________ Order: Rocephin 600mg IM x 1 b)________ Reference: Rocephin 50-75mg/kg/24hr, not it exceed 2gm/day.

Child weighs 19lbs, 8oz. On hand is Rocephin 1g. Instructions for reconstitution state to dilute with 2.4ml sterile water to yield a concentration of 1g/2.5ml.

a. Is this a safe dose?

b. If this is a safe dose, how many ml will you administer?

10a. ______ b. ______ c. ______

Ordered is ampicillin sodium 100mg IV q6hr. The SDR is 50-100mg/kg/day in 4 divided doses. The child weighs 12 lb 8 oz. Available is ampicillin 2g/100ml.a. What is the SDR for this child?

b. Is the ordered dose safe?

c. How much do you give, if safe dose?

11a. ______ b. ______ c. ______ d. ______

The order reads Rocephin 700mg IV q12hr. The child weighs 31 lb. The SDR is 75-100mg/kg/day in 2 divided doses. Available is Rocephin 1g in powdered form. Directions for reconstitution state add 9.6ml sterile water for injection to equal 100mg/ml. Further dilute to 30ml with a compatible solution in a volume-control device and give over 30minutes.a. What is the SDR for this child?

b. Is the ordered dose safe?

c. How many ml of the reconstituted Rocephin do you draw up and add to the volume-control device? How many ml of the compatible IV solution do you further dilute with?

d. What is the rate of infusion, if safe dose?

16

Advanced IV Metrology Answer KeyElectronically Regulated Flow Rates (ml/hr) 2a. 65kg1. 500ml/hr b. 1170units2. 225ml/hr c. 12ml/hr3. 200ml/hr d. 1000units bolus; gtt by 100Uunitshr; 13ml/hr4. 250ml/hr e. gtt by 100units/hr; 14ml/hr5. 133ml/hr Advanced/Critical Care IV Infusions6. 200ml/hr 1. 210ml/hr7. 63ml/hr 2. 6ml/hr8. 125ml/hr 3. 75ml/hr9. 200ml/hr 4. 30ml/hr10. 150ml/hr 5. 18ml/hrManually Regulated Flow Rates (gtt/min) 6. 45ml/hr1. 167gtts/min 7. 39ml/hr2. 28gtts/min 8. 23ml/hr3. 33gtt/min Pediatric Doses4. 25gtts/min 1. 3.64kg5.100gtt/min 2. 2.5kg6. 50gtt/min 3. 1.99kg7. 17gtt/min 4. 8.44kg8. 100gtt/min 5. Yes: SDR=115-346mg/day (300mg/day ordered)9 67gtt/min 6. No: SDR=1500-3000mcg/day (3600mcg/day ordered)10. 38gtt/min 7a. 1190-1586mg/day (Safe:1400mg/day ordered)Timing IV Push Medications b. 2.8ml1. 2ml; 2min; 1ml/min 8a. 422-633mg/24hrs (Safe: 600mg/day ordered)2. 1.5ml; 6min; 0.25ml/min b. 1.7ml3. 1ml; 5min (per drug reference); 0.2ml/min 9a. Yes: SDR=443-665mg/24hr (600mg dose ordered)4. 1.5ml; 1.5min; 1ml/min b. 1.5ml5. 10ml; 10min; 1ml/min 10a. 284-568mg/dayContinuous Medicated IV Infusions b. Yes (400mg/day ordered)1. 35ml/hr c. 5ml2. 20ml/hr 11a. 1057-1409mg/day3. 15ml/hr b. Yes (1400mg/day ordered)4. 3mEq/hr c. 7ml; 23ml5. 3mg/hr d. 60ml/hr6. 1g/hr 12a. 250-500mg q 6hrs (up to 1000-2000mg/day)Titrating Heparin Infusions b. Yes: 400mg q 6hrs (1600mg/day) is ordered1a. 60kg c. 4ml; 16ml b. 1020units d. 40ml/hr c. 20ml/hr d. 2000units bolus; gtt by 200units/hr; 24ml/hr e. 1000units bolus; gtt by 100units/hr; call MD; 26ml/hr

17

Documents

Advanced IV-Metrology F090