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Intravenous Fluid and Drug TherapyIntravenous Fluid and Drug Therapy

Calculating IV Components as PercentagesCalculating IV Flow RatesFlow Rates for Electronic Regulation

Intermittent Intravenous InjectionsIV Piggybacks

4. Calculate the drug dosage for IV push medications.5. Calculate the flow rate for IV solutions.6. Calculate IV flow rates for electronic regulation.

intermittent intravenous infusion Medication administrationas a single dose into a vein that has been maintained open with anIV catheter.

intermittent peripheral infusion device A device attached tothe hub of the IV catheter that allows access to the vein for IV pushmedications; also known as a heparin lock or a saline lock.

IV bolus A quantity of IV fluid that can be run over a specified periodof time through an IV setup attached to the lock.

IV push Drugs that are administered by the direct IV injection route.saline lock A device attached to the hub of the IV catheter that al-

lows access to the vein for IV push medications; also known as a he-parin lock or an intermittent peripheral infusion device.

syringe pump A kind of electronic infusion pump used to infuse flu-ids or medications directly from a syringe.

G L O S S A R Ycontinuous IV infusion Replaces or maintains fluids and elec-

trolytes and serves as a vehicle for medication administration.controllers Devices that are often referred to as electronic flow

clamps because they control infusion rate by either drop counting orvolumetric delivery, using gravity to maintain desired flow rates.

D5W Dextrose 5% in water. In this mixture, the solute is dextrose, andthe solvent is water.

direct intravenous injection A hypodermic injection into a veinfor the purpose of instilling a single dose of medication.

heparin lock A device attached to the hub of the IV catheter that al-lows access to the vein for IV push medications; also known as asaline lock or an intermittent peripheral infusion device.

infusion pump A device that maintains flow by displacing fluid atan ordered rate, rather than relying on gravity.

O B J E C T I V E SUpon completion of this chapter, the student should be able to:

1. Distinguish various types of IV equipment.2. Identify common IV fluid therapies.3. Adjust the flow rates for IV infusions.

O U T L I N EOverviewDirect Intravenous InjectionsContinuous Intravenous Injections

Solution Additives

1 1

1428344225, Pharmaceutical Calculations for Pharmacy Technicians: A Worktext, by Jahangir Moini, MD, MPH - ©Thomson

CHAPTER 11 Intravenous Fluid and Drug Therapy 131

OVERVIEW

The administration of medication or fluids through avein may be ordered for a variety of reasons. Intravenous(IV) fluids and drugs may be administered by threemethods: direct IV drug injection, continuous IV infu-sion, and intermittent IV infusion. Intravenous therapy isprescribed to persons requiring electrolyte replacement,fluid, calories, vitamins, or other nutritional substances.It may also be prescribed for administration of medica-tions, chemotherapy, or for transfusion of blood prod-ucts. Approximately 90% of all hospitalized clients,some outpatients, and some home-care clients receive IVtherapy.

Drugs are administered intravenously for direct ab-sorption and fast action. Therefore, calculation errors canhave serious, even fatal, consequences. Drug informationinserts must be read carefully, and attention must be paidto the amount of drug that can be given per minute. If thedrug is administered into the blood circulation at a ratefaster than that specified in the drug literature, adverse re-actions to the medication are likely to occur.

DIRECT INTRAVENOUS INJECTIONS

A direct intravenous injection is a hypodermic injectioninto a vein for the purpose of instilling a single dose ofmedication. The substance being injected may be a con-trast medium, or the beginning of an IV infusion of blood,medication, or a fluid solution, such as saline or dextrosein water. Drugs that are administered by the IV injectionroute are often referred to as IV push.

Dosage calculations for IV push injections are the sameas calculations for intramuscular (IM) injections. Mosttimed IV push administration recommendations are for1–5 minutes or more. Remember that IV drugs are potentand rapid acting. Never infuse IV push drugs more rapidlythan recommended by agency policy or pharmacology lit-erature. Medications that are given by this route have arapid onset of action, and calculation errors can have seri-ous or even fatal consequences. Calculating the amount ofdrug needed to infuse by direct IV infusion can be deter-mined by using the ratio and proportion method.

EXAMPLE 1:Ordered: Dilantin 200 mg IV statOn hand: Dilantin 250 mg / 5 mL. IV infusion

not to exceed 50 mg / min

Give:DH* V =

200250

* 5 = 4 mL

orH : V : : D : X250 mg : 5 mL : : 200 mg : X mL250X � 5 � 200 � 1000

X � 4 mLMinutes : : desired drug : desired minutes50 mg : 1 minute : : 200 mg : x minutes50X � 200X � 4 minutes

X =1000250

EXAMPLE 2:Ordered: furosemide 120 mg IV statOn hand: furosemide 10 mg / mL. IV infusion

not to exceed 40 mg / mina. H : V : : D : X

10 mg : 1 mL : : 120 mg : X10X � 120X � 12 mL of Lasix

or

b. On hand: minutes : : desired drug : desiredminutes

40 mg : 1 min : : 120 mg : X40X � 120X � 3 min

DH* V =

1 mL * 120 mg10 mg * 1

= 12 mL of Lasix

EXAMPLE 3:Ordered: Ativan 3 mg IV push 20 min

preoperativelyOn hand: Ativan 4 mg / mL with drug

literature guidelines of “IV infusionnot to exceed 2 mg / min”

How much Ativan should you prepare?Use the formula:

What is a safe infusion time?DH* Q =

3 mg2 mg

* 1 min =32= 1 1�2 min

DH* Q =

3 mg2 mg

* 1 mL = 0.75 mL

ic inject

or

that specifiedthe medicatio

n the drug literare likely to occ

ure, adverse re-r.

not to exV : mg : 1 mL : : 12

a. H10

d 40 mg / mi

mg

faster thaactio


132 CHAPTER 11 Intravenous Fluid and Drug Therapy

CONTINUOUS INTRAVENOUS INJECTIONS

Continuous IV infusions replace or maintain fluids andelectrolytes and serve as a vehicle for medication adminis-tration. Intravenous solutions are ordered by a practi-tioner. The pharmacy technician must be sure that thecorrect IV fluid is administered to the correct patient at theprescribed rate. IV fluids can be supplied in plastic solu-tion bags or glass bottles with the volume of the IV fluidcontainer typically varying from 50 mL to 1,000 mL(Figure 11-1). Some IV bags may even contain more than1,000 mL. Solutions used for total parenteral nutritionusually contain 2,000 mL or more in a single bag. The IVsolution bag or bottle will be labeled with the exact com-ponents and amount of the IV solution. Pharmacy techni-cians often use abbreviations when communicating aboutthe IV solution. Therefore, it is important for the techni-cians to know the common IV solution components andthe solution concentration strengths represented by suchabbreviations (Table 11-1).

EXAMPLE 4:Ordered: Cefizox 1500 mg IV push q8hOn hand: Cefizox 2 g powder with directions,

“For direct IV administration,reconstitute each 1 g in 10 mL sterile water and give slowly over3–5 minutes”

How much Cefizox should you prepare?2 g � 2 � 1000 � 2000 mg

What is a safe infusion time?

Administer 15 mL over 7.5 min.

DH* Q =

1500 mg1000

* 5 min =152= 7.5 min

DH* Q =

1500 mg2000 mg

* 20 mL = 15 mL

STOP AND REVIEWSTOP AND REVIEW

Calculating IV Push Rates

1. Ordered: morphine sulfate 6 mg IV push q3hp.r.n., pain

On hand: morphine sulfate 10 mg / mL with awritten drug referencerecommendation, “IV infusion not toexceed 2.5 mg / min”

Given: _________ mL / _________ min / _______ sec

2. Ordered: Oxacillin Sodium 900 mg in 125 mL D5WIV PB to be infused over 45 min

Use an infusion pump.Flow rate: __________ mL / hr

3. Ordered: Versed 1.5 mg IV push statOn hand: Versed 1 mg / 1 mLInstructions: “Slowly titrate to the desired effect

using no more than 1.5 mg initially givenover 2-min period.”

Prepare: __________ mL VersedGiven: __________ mL / sec

4. Ordered: Merrem 1 g in 100 mL D5W IV PB to beinfused over 50 min

Use an infusion pump.Flow rate: __________ mL / hr

5. Ordered: Unasyn 1.5 g in 50 mL D5W IV PB to beinfused over 15 min

Drop factor: 15 gtt / minFlow rate: __________ gtt / min

6. Ordered: Keflin 500 mg in 50 mL NS IV PB to beinfused over 20 min

Drop factor: 10 gtt / mLFlow rate: __________ gtt / min

7. Ordered: Ancef 1 g in 100 mL D5W IV PB to beinfused over 45 min


8. Ordered: Zosyn 1.3 g in 100 mL D5W IV PB to beinfused over 30 min

Drop factor: 60 gtt / minFlow rate: __________ gtt / min

9. Ordered: Dilantin 150 mg IV push statOn hand: Dilantin 250 mg / 5 mL with drug insert,

which states “IV infusion not to exceed50 mg / min”

Given: __________ mL / __________ min

10. Ordered: Cimetidine 300 mg IV push statOn hand: Tagamet (cimetidine) 300 mg / 2 mLInstructions: “For direct IV injection, dilute 300 mg in

0.9% NaCl to a total volume of 20 mL.Inject over at least 2 minutes.”

Prepare: __________ mL TagametDilute with: __________ mL 0.9% NaCl for a total of

20 mL of solutionAdminister: __________ mL / min

D D D REVIEWREVIEWREVIEWOPSSTOP ANSTOP AN



EXAMPLE 1:Suppose an order includes D5W. Thisabbreviation means “Dextrose 5% in Water,”and it is supplied as 5% dextrose Injection(Figure 11-2). This means that the solutionstrength of the solute (dextrose) is 5%. The solventis water. Read the IV bag label and notice that“each 100 mL contains 5 g dextrose . . .” Forevery 100 mL of solution, there are 5 g ofdextrose.

Figure 11-1. IV solutions come in various sizes.

Figure 11-2. D5W. (Courtesy of Baxter Healthcare Corporation)

T A B L E 1 1 - 1 . C o m m o n I V C o m p o n e n t A b b r e v i a t i o n s

ABBREVIATION SOLUTION COMPONENT

D Dextrose

W Water

S Saline

NS Normal Saline

NaCl Sodium Chloride

RL Ringer’s Lactate

LR Lactated Ringer’s

Figure 11-3. D5LR. (Photography courtesy Abbott Laboratories)

EXAMPLE 2:Suppose a physician writes D5LR on theprescription. This abbreviation means “Dextrose5% in Lactated Ringer’s” and is supplied aslactated Ringer’s and 5% dextrose injection, asshown in Figure 11-3.

EXAMPLE 3:A physician orders D5NS 1,000 mL IV q8h. Thisorder is translated as “administer 1,000 mL of5% dextrose in normal saline intravenously every8 hours.” It is supplied as 5% dextrose and 0.9%




Intravenous Solutions and Additives

1. For each of the following IV solutions labeled A through H, specify the letter of the illustration corresponding to the fluidabbreviation, list the solute(s) of each solution and identify the strength (g / mL) of each solute, and identify the osmolarity(mOsm / L) of each solution.

Letter of Components OsmolarityMatching and Strength (mOsm / L)Illustration

a. NS __________ __________ __________b. D5W __________ __________ __________c. D5NS __________ __________ __________d. D5 1/2 NS __________ __________ __________e. D5 1/4 NS __________ __________ __________f. D5LR __________ __________ __________g. D5 1/2 NSc

20 mEq KCl / L __________ __________ __________h. 1/2 NS __________ __________ __________

Solution AdditivesIn some cases, electrolytes, nutrients, and medications canbe added and mixed with IV solutions. Antibiotics, potas-sium chloride, and water-soluble vitamins such as B and Care common additives. If additives are prepackaged in the

EXAMPLE:The physician orders D5Nsc20 mEq KCl / L. Thismeans to add 20 milliequivalents of potassiumchloride per liter of 5% dextrose and 0.9%sodium chloride IV solution.

sodium chloride. The common term for 0.9%sodium chloride is normal saline (also known asphysiologic saline). In normal saline, theconcentration of sodium chloride is 0.9 g (whichis equal to 900 mg) per 100 mL of solution.

solution, the pharmacy technician needs to mix the addi-tive and IV solution himself. The prescriber’s order will ex-plain how much additive is to be given, the amount andtype of basic IV solution to use, or how long it should beinfused.

(A) (Photography courtesy Abbott Laboratories)

(B) (Photography courtesy Abbott Laboratories)



(C) (Photography courtesy Abbott Laboratories) (D) (Photography courtesy Abbott Laboratories)

(E) (Courtesy of Baxter Healthcare Corporation)

(F) (Courtesy of Baxter Healthcare Corporation)

(continues)



CALCULATING IV COMPONENTS AS PERCENTAGES

The concept of calculating components of IV solution byexpressing them as a percent is important because it helpsin understanding that IV solutions provide much morethan fluid. They also provide other components.

EXAMPLE 1:Ordered: D5W 1,000 mLCalculate the amount of dextrose in 1,000 mLD5W. This can be calculated using ratio andproportion. Recall that % indicates g per 100 mL;therefore, 5% dextrose is 5 g dextrose per 100mL of solution.

100X � 5000

X =5000100

= 50 g

5 g100 mL

=Xg

1000 mL

EXAMPLE 2:Ordered: D51/4 NS 500 mLCalculate the amount of dextrose and sodiumchloride in 500 mL.

100X � 2500

1/4 NS � 0.225% NaCl � 0.225 g NaCl per100 mL(Recall that NS, or Normal Saline, is 0.9% NaCl;therefore, 1/2 NS is 1/4 � 0.9% � 0.225%NaCl)

100X � 112.5X � 1.125 g NaCl500 mL D51/4 NS contains 25 g dextrose and1.125 g sodium chloride.

0.225 g100 mL

=Xg

500 mL

X =2500100

= 25 g dextrose

5 g100 mL

=Xg

500 mL

(G) (Photography courtesy Abbott Laboratories)

(H) (Photography courtesy Abbott Laboratories)

(continued)




Calculating IVs as Percentages

1. Calculate the amount of dextrose and/or sodiumchloride in each of the following IV solutions.a. 250 mL NS

sodium chloride __________gb. 3 L of D5NS

dextrose __________gsodium chloride __________g

c. 500 mL of D5 0.33% NaCldextrose __________gsodium chloride __________g

d. 250 mL of D10Wdextrose __________g

e. 1,000 mL of D5NSdextrose __________gsodium chloride __________g

f. 750 mL of NSsodium chloride __________g

g. 0.75 L of 0.45% NaClsodium chloride __________g

h. 300 mL of D12 0.9% NaCldextrose __________gsodium chloride __________g

i. 500 mL of D51/2 NSdextrose __________gsodium chloride __________g

j. 0.5 L of D101/4 NSdextrose __________gsodium chloride __________g

Calculating IV Flow RatesIntravenous fluids are administered via an intravenous in-fusion set. This primary line usually includes the sealedbottle or bag containing the fluids, a drip chamber con-nected to the bag or bottle by a small tube or spike, a rollerclamp, and tubing that leads from the roller clamp downto and connecting with the needle or catheter at the site ofinsertion into the patient (Figure 11-4). The nurse can ei-ther regulate the rate by using the roller clamp or place thetubing in an electronic infusion pump.

There is also another type of IV tubing (the secondaryintravenous tubing) that is used when medications areadministered by “piggybacking” into the primary line(Figure 11-5).

To measure the flow rate, the drip chamber must besqueezed until it is half full, making it easier to appropri-ately count the number of drops falling into the chamber.The roller clamp is used to adjust the speed of the infusioneither up or down as needed. The injection port is avail-able to inject medications into the primary line or to attacha second intravenous line. Two sizes of tubing are available:macrodrop and microdrop. Macrodrop tubing is used for

Figure 11-4. Standard IV setup.

Figure 11-5. Piggyback IV setup.



fluids infused at a higher rate, for example, infusions thatare set at 80 mL / hr or higher. Microdrop tubing is usedfor slower infusions for which accuracy of dosage deliveryis essential, such as in critical care or pediatric settings.

It is important for the nurse to accurately set andmaintain the flow rate to administer the prescribed vol-ume of the IV solution within the specified time period.The nurse records the IV fluids administered and IV flowrates on the IV administration record (Figure 11-6).

IV fluids are usually ordered for a certain volume torun for a stated period of time, such as 125 mL / h or 1,000mL / 8h. The nurse may use electronic or manual regulat-ing equipment to monitor the flow rate. The calculationsperformed to set the flow rate will depend on the equip-ment used to administer the IV solutions.

The infusion of intravenous fluids is monitored inmany different ways. Most times, for manual regulation,the bag containing the intravenous solution is hung 36inches above the patient’s heart so that gravity will drawthe fluid into the patient. When the infusion is regulated,the roller clamp is used to adjust the rate of delivery.Therefore, the nurse manually regulates the IV rate. Tocalculate the ordered IV rate based on a certain number ofdrops per minute (gtt / min), understand that this actuallyrepresents the ordered milliliters per hour. For calculatingflow rate manually, you must count the number of dropsdripping count IV rate based on a certain number of dropsper minute (gtt / min). The number of drops dripping perminute into the IV drip chamber are controlled andcounted by opening and closing the roller clamp. The

D51⁄2 NS

0800 22 1 1⁄2" I LH 1 O GP

GP G. Pickar, R.N.

100 ml/hr 0900 GP LH PIV

11/10/xx

Smith, James 43y MDr. Jones Medical ServiceAdmitted 01-01-xx Rm 237-1Adm. # 6634297

1 1

NKA

Figure 11-6. Intravenous administration record.



Figure 11-7. Primary intravenous infusion set. (Photographycourtesy Abbott Laboratories)

drop factor is the number of drops per milliliter (gtt / mL)that a particular IV tubing set will deliver. It is written onthe IV tubing package (Figure 11-7) and varies accordingto the manufacturer of the IV equipment. Standard ormacrodrop IV tubing sets have a drop factor of 10, 15, or20 gtt / mL. All microdrip IV tubing have a drop factor of60 gtt / mL.

Figure 11-8 compares macro- and microdrops. Figure11-9 illustrates the size and number of drops in 1 mL foreach drop factor. Notice that the fewer the number ofdrops per milliliter, the larger the actual drop size.

Figure 11-8. Intravenous drip chambers: (A) macrodrops; (B) microdrops.

1 mL

10 gtt/mL 15 gtt/mL 20 gtt/mL 60 gtt/mL

Microdrop CalibrationStandard or Macrodrop Calibration

1 mL 1 mL 1 mL

Figure 11-9. Comparison of calibrated drop factors.




Calculating IV Flow Rates

1. Identify the drop factor calibration of the IV tubing pictured.

(A) (Photography courtesy Abbott Laboratories)

(B) (Photography courtesy Abbott Laboratories) (C) (Photography courtesy Abbott Laboratories)

(D) (Photography courtesy Abbott Laboratories) (E) (Courtesy of Baxter Healthcare Corporation)

To calculate IV flow rates for manual regulation, there aretwo methods: the formula method and the shortcut method.

Formula Method

The formula method is used to determine the flow rate indrops per minute (gtt / min).

� Calibration or drop factor (gtt / mL)

� Rate (gtt / min)

Volume (mL)

Time (min)

V

T* C = R

In this formula:

V � volume per hour to be infused in mL ordered bythe prescriber

T � time converted to minutes ordered by theprescriber

C � calibration of tubing (drop factor) in gtt / mLR � rate of the flow in gtt / min



EXAMPLE 1:The prescriber orders 1000 mL to be infused over8 hours, with a drip factor of 30 gtt / mL.First determine the mL / hour.1000 mL / 8 hours � 125 mL per hourThen use this formula:

So,

� 62.5 gtt / min

125 mL � h * 30 gtt �mL60 minutes

=3750

60

mL �hour * gtt �mL60 minutes

EXAMPLE 2:The physician orders 500 mL to be infused over24 hours, with a drip factor of 60 gtt / mL.

� 20.8 gtt / min(may be rounded to 21 drops per minute)

20.8 mL � hr * 60 gtt � mL60 minutes

= 1248 � 60

500 mL24 hours

= 20.8 mL per hour

EXAMPLE 3:The physician orders 250 mL to be infused over3 hours, with a drip factor of 15 gtt / mL.250 mL / 3 hours � 83.3 mL per hour

� 20.8 gtt / min


=1249.5

60

EXAMPLE 4:The prescriber orders 350 mL to be infused over4 hours, with a drip factor of 8 gtt / mL.350 mL / 4 hours � 87.5 mL per hour

� 11.7 gtt / min (rounded to 12 gtt / min)


=70060


Manually Calculating IV Flow Rates Using the FormulaMethod

1. Calculate the flow rate or watch count in gtt / min.a. Ordered: D5 NS IV at 150 mL / hr


b. Ordered: 3,500 mL D5 LR IV to run at 160 mL / hDrop factor: 15 gtt / mLFlow rate: __________ gtt / min

c. Ordered: 80 mL D5W antibiotic solution IV to in-fuse in 60 min


d. Ordered: 250 mL LR IV at 50 mL / hrDrop factor: 60 gtt / mLFlow rate: __________ gtt / min

e. Ordered: 480 mL packed red blood cells IV toinfuse in 4 hours


f. Ordered: 2,500 mL LR IV at 165 mL / hrDrop factor: 20 gtt / mLFlow rate: __________ gtt / min

g. Ordered: 100 mL NS bolus IV to infuse in 60 minDrop factor: 20 gtt / mLFlow rate: __________ gtt / min

h. Ordered: Two 500 mL units of whole blood IV tobe infused in 4 hours

Infusion set is calibrated to 20 drops per milliliter.Flow rate: __________ gtt / min

Shortcut Method

This method is used when converting the volume andtime in the formula method to mL / hr (or mL / 60 min) touse as a shortcut for calculating flow rate.

EXAMPLE 1:Dr. Smith has ordered 125 mL / hr IV with a 20gtt / mL infusion set. You can calculate thisexample using the formula:

� 41.7 gtt / min = 42 gtt / min

125 mL60 min

* 20 gtt � mL =125 gtt3 min

60

4 hours, with 4 h ith500 L4 h

20

drip factor of 60d i f t f 6

mL per hour

gtt / mL.tt / L



Adjusting IV Flow Rates

When IV fluids are added with medicines, the rate of flowmust be carefully calculated and close observation at reg-ular intervals must be conducted. Various situations suchas gravity, condition, and movement of the patient can al-ter the set flow rate of an IV, causing the IV to run aheadof or behind schedule. Therefore, the flow rate per minutemay be adjusted by up to 25% more or less than the orig-

EXAMPLE 2:Ordered: Normal Saline 1,000 mL IV at 125

mL / hr with a microdrop infusionset calibrated for 60 gtt / mL. Usethe formula:

� 125 gtt / min

125 mL60 min

* 60 gtt � mL =125 gtt1 min

VT* C = R


Manually Calculating IV Flow Rates Using the ShortcutMethod

1. Calculate the IV flow rate in gtt / min using the shortcutmethod.a. Ordered: 650 mL D5 0.33% NaCl IV to infuse in

10 hrDrop factor: 10 gtt / mLFlow rate: __________ gtt / min

b. Ordered: 500 mL D5W 0.45% Saline IV to infuseat 165 mL / hr


c. Ordered: 3L NS IV to infuse at 125 mL / hrDrop factor: 15 gtt / mLFlow rate: __________ gtt / min

d. Ordered: 400 mL D5W IV to infuse at 50 mL / hrDrop factor: 10 gtt / mLFlow rate: __________ gtt / min

e. Ordered: 0.5 L 0.45% NaCl IV to infuse in 20 hrDrop factor: 60 gtt / mLFlow rate: __________ gtt / min

f. Ordered: 1,000 mL D5W IV to infuse at 200 mL / hrDrop factor: 15 gtt / mLFlow rate: __________ gtt / min

g. Ordered: 2L NS IV to infuse at 60 mL / hr with microdrop infusion set of 60 gtt / mL

Flow rate: __________ gtt / minh. Ordered: 500 mL D5 LR to infuse in 6 hr


inal rate depending on the condition of the patient. Insuch cases, assess the patient. If the patient is stable, re-calculate the flow rate to administer the total milliliters re-maining over the number of hours remaining of theoriginal order.

Use the following formula to recalculate the mL / hrand gtt / min for the time remaining and the percentage ofvariation.

First:

Then:

Last:

Adjusted gtt � min - ordered gtt � min

Ordered gtt � min= % variation

V

T* C = gtt � min

Recalculated mL � hr =Remaining volume

Remaining hours

EXAMPLE 1:The prescriber has ordered 500 mL LR to runover 10 hr at 50 mL / hr. The drop factor is 60 gtt / mL and the IV is correctly infusing at 50 gtt / min. After 2 1/2 hours, you find 300 mLremaining. Almost half of the total volume hasalready infused in about one-quarter the time.This IV infusion is ahead of schedule. You wouldcompute a new flow rate of 300 mL to completethe IV fluid order in the remaining 7 1/2 hours.The patient would require close assessment forfluid overload.Step 1.

Step 2.

(adjusted flow rate)Step 3.

� % of variation

within the

acceptable 25% of variation

40 - 5050

=-1050

= -0.2 = -20%

Adjusted gtt � min - Ordered gtt � minOrdered gtt � min

VT* C =

40 mL60 min

* 60 gtt � mL = 40 gtt � min

300 mL7.5

= 40 mL � hr

Remaining volumeRemaining hours

= Recalculate mL � hr

EXAMPLE 1:




Adjusting Flow Rates

1. Compute the flow rate in drops per minute. Hospitalpolicy permits recalculation of IVs when off schedule,with a maximum variation in rate of 25% for stablepatients. Compute the % of variation.a. Ordered: 2,000 mL NS IV for 16 hr at 125 mL / hr

Drop factor: 15 gtt / mLOriginal flow rate: __________ gtt / minAfter 6 hours, 650 mL of fluid have infused; explainyour action now.Solution remaining: __________ mLTime remaining: __________ hrRecalculated flow rate: __________ mL / hrRecalculated flow rate: __________ gtt / minVariation: __________ %Action: ____________________________________

b. Ordered: 1,000 mL D5W IV for 10 hr at 100 mL / hrDrop factor: 60 gtt / mLOriginal flow rate: __________ gtt / minAfter 5 hours, there are 500 mL remaining; explainyour action now.Time remaining: __________ hrRecalculated flow rate: __________ mL / hrRecalculated flow rate: __________ gtt / minVariation: __________ %Action: ____________________________________

c. Ordered: 1,000 mL NS IV for 8 hr at 125 mL / hrDrop factor: 10 gtt / mLOriginal flow rate: __________ gtt / minAfter 4 hours, there are 750 mL remaining; describeyour action now.Time remaining: __________ hrRecalculated flow rate: __________ mL / hrRecalculated flow rate: __________ gtt / minVariation: __________ %Action: ____________________________________

d. Ordered: 500 mL D5 NS IV for 5 hr at 100 mL / hrDrop factor: 20 gtt / mLOriginal flow rate: __________ gtt / minAfter 2 hours, there are 250 mL remaining; describeyour action now.Time remaining: __________ hrRecalculated flow rate: __________ mL / hrRecalculated flow rate: __________ gtt / minVariation: __________ %Action: ____________________________________

e. Ordered: 1,500 mL lactated Ringer’s IV for 12 hrat 125 mL / hrDrop factor: 20 gtt / mLOriginal flow rate: __________ gtt / minAfter 6 hours, there are 850 mL remaining; explainyour action now.Time remaining: __________ hrRecalculated flow rate: __________ mL / hrRecalculated flow rate: __________ gtt / minVariation: __________ %Action: ____________________________________

Flow Rates for Electronic RegulationIntravenous fluids may be monitored electronically by aninfusion device, which is known as a controller or pump.The indication of an electronic infusion device will be de-termined by the need to strictly control the IV. Manufac-turers provide special volumetric tubing that must be usedwith their infusion devices. This volumetric tubing en-sures accurate, consistent IV infusions. Each device maybe set for a specific flow rate and will set off an alarm if thisrate is interrupted.

Controllers depend on gravity to maintain the desiredflow rate by a compression and decompression mechanismthat pinches the IV tubing, rather than forcing IV fluid intothe system (Figure 11-10). They are often referred to aselectronic flow clamps because they control the selectedrate of infusion by either drop counting (drops per minute)or volumetric delivery (milliliters per hour).

Infusion pumps do not rely on gravity but maintainthe flow by displacing fluid at the ordered rate. Resistanceto flow within the system causes positive pressure in rela-tion to the flow rate (Figure 11-11).

A syringe pump is a kind of electronic infusion pump.It is used to infuse fluids or medications directly from a sy-ringe. It is most often used in pediatric patients when smallvolumes of medication are administered at very low rates.

f. Ordered: 1,000 mL D5 W IV for 8 hr at 125 mL / hrDrop factor: 20 gtt / mLOriginal flow rate: __________ gtt / minAfter 4 hours, there are 800 mL remaining; explainyour action now.Time remaining: __________ hrRecalculated flow rate: __________ mL / hrRecalculated flow rate: __________ gtt / minVariation: __________ %Action: ____________________________________

g. Ordered: 1 L NS IV for 20 hr at 50 mL / hrDrop factor: 15 gtt / mLOriginal flow rate: __________ gtt / minAfter 10 hours, there are 600 mL remaining; explainyour action now.Time remaining: __________ hrRecalculated flow rate: __________ mL / hrRecalculated flow rate: __________ gtt / minVariation: __________ %Action: ____________________________________

h. Ordered: 1,000 mL lactated Ringer’s IV for 6 hr at167 mL / hrDrop factor: 15 gtt / mLOriginal flow rate: __________ gtt / minAfter 4 hours, there are 360 mL remaining; describeyour action now.Time remaining: __________ hrRecalculated flow rate: __________ mL / hrRecalculated flow rate: __________ gtt / minVariation: __________ %Action: ____________________________________



It is also used in anesthesia, labor and delivery, and in crit-ical care when the drug cannot be mixed with other solu-tions or medications (Figure 11-12).

When an electronic infusion regulator is used, the IVvolume is ordered by the physician and programmed intothe device by the nurse. These devices are controlled in mL / hr. Usually the prescriber orders the IV volume to bedelivered in mL / hr. If not, it must be calculated. To regu-late an IV volume by electronic infusion pump or controllercalibrated in mL / hr, you should use the following formula:

Total mL ordered

Total hr ordered= mL�hr

Figure 11-10. Volumetric Infusion Controller/Pump. (Courtesy ofCardinal Health (Alaris Medical System))

Figure 11-11. Infusion pump. (Courtesy of Cardinal Health (AlarisMedical System))

Figure 11-12. Syringe pump. (Courtesy of Medex Inc.)

EXAMPLE:Ordered: D5W 250 mL IV over the next

2 hours by infusion pumpUse the formula:

250 mL2 hr

= 125 mL � 1 hr

Total mL orderedTotal hr ordered

= mL � hr


Calculating IV Flow Rates for Electronic Infusions

1. Calculate the flow rate that you will program theelectronic infusion regulator for the following IV orders.a. Ordered: 380 mL D5 0.45% NaCl in 9 hr by infusion

pumpFlow rate: __________ mL / hr

b. Ordered: 150 mL antibiotic in D5W IV in 2 hr by in-fusion pump

Flow rate: __________ mL / hrc. Ordered: 100 mL NS IV PB in 30 min by infusion

pumpFlow rate: __________ mL / hr

d. Ordered: 750 mL D5W IV in 5 hr by infusion pumpFlow rate: __________ mL / hr

e. Ordered: 3 L NS IV in 24 hr by controllerFlow rate: __________ mL /hr

Ordered: D5W 250 mL IV over the next

Figure mp. (Courtesy of 1-12. Syringe edex Inc



f. Ordered: 1,800 mL Normal Saline IV to infuse in 15hr by controller

Flow rate: __________ mL /hrg. Ordered: 1.5 L D5 NS IV in 12 hr by controller

Flow rate: __________ mL / hrh. Ordered: 2,000 mL D5W IV in 24 hr by controller

Flow rate: __________ mL / hr

INTERMITTENT INTRAVENOUS INJECTIONS

Intermittent intravenous infusions, such as IV piggybackand IV push, are used for IV administration of drugs andsupplemental fluid. Intermittent peripheral infusion de-vices, also known as saline or heparin locks, are used tomaintain venous access without continuous fluid infusion.In the case of a patient needing to get supplemental fluidtherapy or IV medications, but not needing continuous re-placement or maintenance IV fluid, intermittent IV infu-sion systems are generally used. These systems include IVpiggyback, IV locks for IV push drugs, or volume controlsets (such as Bureterol).

IV Piggybacks (IVPB)A medication may be prescribed to be dissolved in a smallamount of IV fluid, for example, 50 to 100 mL and run“piggyback” to the regular IV fluids (see Figure 11-5). Re-call that the piggyback IV (or secondary IV) requires a sec-ondary IV set.

EXAMPLE 1:Ordered: Kefzol 500 mg in 100 mL D5W

IV PB to run over 30 minDrop factor: 20 gtt / mLDetermine the flow rate in gtt / min.

� 66.7 gtt / min � 67 gtt / min

VT* C =

100 mL30 min

* 20 gtt � mL =200 gtt

3

Saline and Heparin IV Locks for IV Push Drugs

IV locks are attached to the hub of the IV catheter that issituated in the vein. The lock is called a saline lock.meaning that saline is used to flush or maintain the IVcatheter patency, or a heparin lock if heparin is used tomaintain the IV catheter patency. Sometimes a more gen-eral term, such as intermittent peripheral infusion de-vice, may be used. Medications can be given IV push,meaning that a syringe is attached to the lock and med-ication is pushed in. An IV bolus, usually a quantity of IVfluid, can be run in over a specified period of time throughan IV setup that is attached to the lock.

In the majority of cases, it is easy to calculate mL / hrby dividing the total mL by the total hr. However, an IVwith medication added or a piggyback IV may be pre-scribed to be injected in less than 1 hour by an electronicinfusion device, but the pump or controller must still beset in mL /hr.

In this situation the following formula can be used:

Total mL ordered

Total min ordered* 60 min � hr = mL � hr

EXAMPLE:Ordered: Amoxicillin 500 mg IV in 50 mLD5 1/2 NS in 30 min by controllerUse the formula:

50 mL30 min

*60 min

1 h= 100 mL � h

Total mL orderedTotal min ordered

* 60 min � hr = mL � hr

T E S T Y O U R K N O W L E D G ET E S T Y O U R K N O W L E D G E

For the following questions, use the drop factor tocalculate the flow rate in gtt / min.

Ordered: 1,000 mL of 0.45% NaCl IV at 200 mL / hr

1. Drop factor 10 gtt / mLFlow rate: __________ gtt / min



Ordered: 540 mL D5 0.33% NaCl at 45 mL / hr

(continues)

A medication may be prescribed to be dissolved in a smallmL and run

)

Ordered: Amoxicillin 500 mg IV in 5

ms are general, IV locks for as Bureterol).

sed. These sV push drugs, or

ems include IVolume control ordered

*Total m

in � h mLsion systepiggets



(continued)





Ordered: 1 L hyperalimentation solution IV to infuse in 12 hr





Ordered: 2 L D5 NS IV to infuse in 20 hr





Complete the flow rate in drops per minute ormilliliters per hour as requested. For these situations,hospital policy permits recalculating IVs when offschedule with a maximum variation in rate of 25%.

16. 1L D10 W IV to run from 1,000 to 1,800Drop factor: on electronic infusion pumpFlow rate: __________ mL / hr

17. Ordered: 1,000 mL D5W IV per 24 hrDrop factor: 60 gtt / mLFlow rate: __________ gtt / min

18. Ordered: 1,000 mL D5W IV for 6 hrDrop factor: 15 gtt / mLAfter 2 hours, 800 mL remain. Explain your actionnow.________________________________________

19. Ordered: 2.5 L NS IV to infuse at 125 mL / hrDrop factor: 20 gtt / mLFlow rate: __________ gtt / mL

20. Ordered: 1,500 mL D5 LR IV to run for 12 hrDrop factor: 20 gtt / mLFlow rate: __________ gtt / min

(Photography courtesy Abbott Laboratories)

The IV tubing package in the accompanying figure is the IV system available in your stock for manually regulated,straight gravity flow IV administration with macrodrop. The patient has an order for 500 mL D5W IV q4h written at1515, and you start the IV at 1530. Questions 21 through 30 refer to this situation.

21. How much IV fluid will the patient receive in 24hours? _______________

22. Who is the manufacturer of the IV infusion set tubing?_______________

23. What is the drop factor calibration for the IV infusionset tubing? _______________

24. What is the drop factor constant for the IV infusion settubing? _______________

25. Using the shortcut (drop factor constant) method,calculate the flow rate of the IV as ordered. Show yourwork.Shortcut method calculation: ____________________Flow rate: __________ gtt / min



26. Using the formula method, calculate the flow rate ofthe IV as ordered. Show your work.Formula method calculation: ____________________Flow rate: __________ gtt / min

27. At what time should you anticipate the first IV bag of500 mL D5W will be completely infused?

28. How much IV fluid should be infused by 1730?__________ mL

29. At 1730 you notice that the IV has 210 mL remaining.After assessing your patient and confirming that hiscondition is stable, what should you do?________________________________________________________________________________________

30. After consulting the physician, you decide to use anelectronic controller to better regulate the flow rate.The physician orders that the controller be set toinfuse 500 mL every 4 hours. You should set thecontroller for __________ mL / hr.

CRITICAL THINKING

1. An elderly patient who had pneumonia was pre-scribed Rocephin 1 g IV q12h by her physician. Themedication, which utilized a new dispensing system,was delivered by the pharmacy technician to the hos-pital unit. 1 g of Rocephin was supplied as a powderattached to a 50 mL IV bag of 5% dextrose in water.The nurse hung the IV medication and infused thesolution. Three days later, another nurse discoveredthat the Rocephin powder was still in the vial, andthat the vial stopper had never been opened. Thepowder had not been mixed into the IV fluid duringthis entire period. The nurse who made the error hadnever worked with this new dispensing system anddid not ask for instructions either from the pharmacytechnician or another nurse. The pharmacy techni-cian did not include the dispensing instructions orexplain the dispensing procedure to the nurse. As aresult of this situation, what could possibly happen tothe patient’s pneumonia? What could result in the pa-tient’s condition from this change?


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