2. LEARNING OBJECTIVE
Solve simple problems by using Dimensional Analysis.
Identify some common units of measurement and their
abbreviations.
Construct unit fractions from equivalences.
Convert a quantity expressed with a single unit of
measurement to an equivalent quantity with another
single unit of measurement.
Convert a quantity expressed as a rate to another rate.
Solve complex problems using Dimensional Analysis.
DR MUSA 2
3. • Using the dimensional analysis format to solve oral dosage
problems
• Using the dimensional analysis format to solve parenteral dosage
problems
• Using the dimensional analysis format to solve problems of
intravenous flow rate in drops per minute
• Using the dimensional analysis format to solve problems involving
administration of medications in units per hour
• Using the dimensional analysis format to solve problems involving
administration of medications in milligrams per minute, micrograms
per minute, and micrograms per kilogram per minute
• Using the dimensional analysis format to solve pediatric and
obstetrical dosage problems
DR MUSA 3
4. Background: Dimensional Analysis
• Fancy name—simple technique
• Used to manipulate units in a calculation
• Involves cancellation of unwanted units
• Eliminates need to memorize formulas
• Also known as the factor-label method or the
unit factor method
• Only one equation is used
5. Making Conversions Using
Dimensional Analysis (cont’d)
5. Identify unwanted or undesired units and
cancel, then reduce to lowest terms
6. Must be able to eliminate all labels except for
answer label—if not, recheck
7. Perform mathematical process
Note: it is key to have the
equivalent set up correctly!
6. TERMS
• GIVEN QUANTITY:
➢ Values given in the question and includes
❖ Doctor’s order
❖ Dosage to be given
➢ May be use to begin point in answering the question
• WANTED QUANTITY:
➢ What you desire
➢ Answer to the problem
• UNIT EQUIVALENCY:
➢ Value of equivalencies between two different units
➢ Are not usually given in a question and needs to be memorize
• CONVERSION FACTORS:
➢ Unit Equivalent expressed in fraction
➢ Help to cancel out unwanted units from the problem
➢ May be use to begin the solution of the question
• UNIT PATH:
➢ Series of conversions necessary to achieve the answer to the problem
• UNIT:
➢ A dimension that is given to a number
DR MUSA 6
7. • Identify what is been measured
• Identify the unit of what is been measured and record it to begin the
equation
• Write the equal sign after the unit of measure
• Identify variable from the either the given quantity or unit equivalent
with one of its units similar to the numerator unit of the unit of measure
and record it after the equal sign as a conversion factor in such a way
that the conversion factor have similar numerator unit as the unit of
measure
• Add subsequent variables from the given quantity or unit equivalent by
such the unwanted units is canceled and the desire units are left
• Multiple the numerator values and record with the desire unit left
• Multiple the denominator values and record desire unit left
• Divide the two values to get desire value record it with the desire units
DR MUSA 7
8. TERMS & TERMINOLOGIES
• GIVEN QUANTITY:
❖ Quantities/variables give in the problem:
includes
❖ Doctor’s order
❖ Dosage to be given
❖ On hand
❖ Some unit equivalents
• WANTED QUANTITY: (MEASURE)
❖ What you desire
❖ What you measuring
❖ Answer to the problem
• UNIT EQUIVALENCY:
❖ Value of equivalencies between two different
units
❖ Are not usually given in the problem
❖ Need to be memorized
❖ Are use in solution as conversion factors
• CONVERSION FACTORS:
❖ Unit Equivalent expressed in fraction
❖ Help to cancel out unwanted units from the
problem
• UNIT PATH:
❖ Series of conversions necessary to achieve
the answer to the problem
• UNIT:
❖ A dimension that is given to a number
• FLOW RATE: volume of fluid administer per unit
time
• DRIP RATE: number of drops per unit time
• CONCENTRATION: weight of solute in a unit
volume of solution
• DOSAGE: weight of medication per unit time
administered
DR MUSA 8
9. DROP FACTOR: Is the number of drops through the eye of dropper of a given set
that is required to move (infuse) 1ml of the fluid into the drip chamber (i.e. patient).
The label on the tubing box/packet will indicate the dropper capacity of the specific
tubing used*. The calibration of IV tubing in gtt/ml is known as the drop factor.
Common macrodrop factors are 10 gtts/mL, 15gtts/mL, 20gtts/mL and the common
microdrop factor are 40gtts/ml, 50gtts/ml and 60gtts/mL. Determine drip capacity by
choosing the microdrop chamber or macrodrip chamber. A MICRO OR MINI DRIP
SET which delivers 40-60gtts/ml
• All medicated infusion to give as
accurately as possible and to
minimized overdose. tubing is
narrower and so produces smaller
drops.
• children and infants (paediatrics),
• infusion sensitive medications where
precision in the flow rate is essential
(critical care)
• If you are infusing any
fluid UNDER 60
ML/HR
Microdrip tubing
(sometimes called
minidrip) comes in only
one size: 60 gtt/mL. when
it is use as the IV infusion
set, the Flow rate value is
always equal to the drip
rate value.
DR MUSA 9
10. Mathematical foundation for
dimensional analysis
• Concept 1:
• when a non zero quantity is divided by the
same amount the result is 1
• Concept 2:
• When a quantity is multiply by 1, the quantity
is unchanged
DR MUSA 10
11. • There is more than one way to set up a dimensional
analysis equation. You can begin with:
➢ the given quantity (desired dose)
➢ A unit equivalent who has a unit similar to the numerator
unit of the units of measure(wanted quantity).
• There are four ways to set up the equation. No matter
which fraction placement you use, the equation is
designed for multiplication and cancellation. Three of
the following examples start with the given quantity,
and one starts with the wanted quantity. One problem
will be used to demonstrate each of the four
approaches.
DR MUSA 11
12. METHODS
In both methods identify the dimensions of the wanted
Quantity (unit of measure):
• SEQUENTIAL:
❖The conversion factors are place in the Unit Path such that the
dimensions sequentially cancels those adjacent to them. Begin
with either
➢Given quantity
➢A unit equivalence with one of its units similar to the numerator unit of the
units of measure (wanted quantity)
• RANDOM:
❖The conversion factors are randomly place in the Unit Path such
that the dimensions may cancels those away from to them. Begin
with either
➢Given Quantity
➢Wanted Quantity
DR MUSA 12
13. 1. The order is infuse Pitocin 20U in 500ml of D5W at 100microdrops/min . Calculate the mU/min, ml/hr and
mU/hr that the patient will receive.
• Measure is dosage
• Unit of measure mU/min
• Microdrop means calibration of the IV set is 60drops given for every ml. 100microdrop/min means
100drops/min was given using IV set which gives 60drops for every milliliter
• mU/min = 1000mU/1U × 20U/500ml × 1ml/60drops × 100drops/min
• = 2000000mU/30000min
• = 66.67mU/min
• Measure is Flow rate
• Unit of measure ml/hr
• 100micrdrop/min means 100drops/min was given using IV set which gives 60drops for every milliliter
• ml/hr = 1ml/60drops × 100drops/min × 60min/hr
• = 6000ml/60hr
• = 100ml/hr
• Measure is dosage
• Unit of measure mU/hr
• 100micrdrop/min means 100drops/min was given using IV set which gives 60drops for every milliliter
• mU/hr = 1000mU/1U × 20U/500ml × 1ml/60drops × 100drops/min × 60min/hr
• = 120000000mU/30000hr
• = 4000mU/hr
DR MUSA 13
15. Unit of mU/min
Microdrops implies IV infusion set use gives 60drops for every 1ml infused
100microdrops/min implies 100drops/min was given using an infusion set that gives 60drops for
every 1ml
100ml
6000ml
in
hr
60hr
• Measure is Flow rate
• Unit of measure ml/hr
• 100micrdrop/min means 100drops/min was given using IV set which gives 60drops for every
milliliter
66.67mU
200000m
U
100
drop
s
1ml
20U
1000m
U
mU
min
30000min
min
60drop
s
500m
l
1U
min
DR MUSA 15
16. 1. Order: Drug A 20mg for child. Available: Drug A 20mg in 5ml vial. Dilute to
50ml and administer in 2hr. What is the flow rate in drops per minutes?
▪ Medicated infusion, infusion rates less than 60ml/hr, sensitive
medication that requires precision in their infusion rate (critical
care) or paediatric (infants and children) fluid infusion should
always use microdrip IV set with 60drops per ml
▪ Measure is flow rate
▪ Unit of measure drops per minutes drops/min
▪ drops/min = 60drops/ml x 50ml/2hr x 1hr/60min
= 3000drops/60min
= 50drops/min
DR MUSA 16
17. 1. A doctor orders pitocin drip at 45microdrips per minute. The solution contains 20U of Pitocin in 1000ml of
D5W. Calculate the units per minute, milliliter per hour and the unit per hour the patient is receiving.
• Measure is dosage
• Unit of measure is unit per minute ie U/min
• Note microdrips means the set calibration is 60drops/ml
• U/hr = 20U/1000ml × 1ml/60drops × 45drops/min
• = 900U/60000min
• = 0.015U/min
•
•
• Measure is Flow rate
• Unit of measure ml/hr
• 45micrdrop/min means 45drops/min was given using IV set which gives 60drops for every
milliliter
• mg/hr = 1ml/60drops × 45drops/min × 60mins/hr
• = 2700ml/60hr
• = 45ml/hr
•
• Measure is dosage
• Unit of measure is unit per hour ie U/hr
• U/hr = 20U/1000ml × ml/60drops × 45drops/min × 60min/hr
• = 54000U/60000hr
• = 0.9U/hr
DR MUSA 17
18. 1. The order is infuse Dopamine 400mg in 250ml of D5W at 30microdrops/min . Calculate the mg/min, ml/hr and
mg/hr that the patient will receive.
•
• Measure is dosage
• Unit of measure mg/min
• Microdrop means calibration of the IV set is 60drops given for every ml. 30microdrop/min means
30drops/min was given using IV set which gives 60drops for every milliliter
• mg/min = 400mg/250ml × ml/60drops × 30drops/min
• = 12000mg/15000min
• = 0.8mg/min
•
• Measure is flow rate
• Microdrop/min implies that the IV set use gives 60drops for every milliliter
• Unit of measure ml/hr
• ml/hr = 1ml/60drops x 30drops/min x 60min/1hr
• = 1800ml/60hr
• = 30ml/hr
•
• Measure is dosage
• Unit of measure mg/hr
• 30micrdrop/min means 30drops/min was given using IV set which gives 60drops for every milliliter
• mg/hr = 400mg/250ml × ml/60drops × 30drops/min × 60min/hr
• = 720000mg/15000hr
• = 48mg/hr
DR MUSA 18
19. EXAMPLE
The physician has ordered 500mL D5W with 5units
oxytocin intravenously. Begin at 5mU/min and then
increase by 5mU every 30minutes until active labor
is achieved. Maximum dose is 30mU/min.
a. Calculate the IV rate (ml/hr) for the beginning
infusion?
b. What is the maximum IV drip rate (drops/min)
the Pitocin infusion may be set for?
DR MUSA 19
20. Sequential Method 1
• Identify the Wanted Quantity and Unit(unit of measure)↔
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
• Identify the Unit Equivalencies and Conversion Factors write them as Unit equivalencies
• 5𝑈 = 500𝑚𝑙; 1U = 1000mU; 20drops = ml; 1hr = 60min; 30mU = min
• Create a unit paths
➢ Write dimensions of wanted quantity(unit of measure) as Conversion factor to begin the equation:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
➢ Write an equal sign:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
➢ Begin with a Unit Equivalent that has drops as one of its dimension :
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
𝑑𝑟𝑜𝑝𝑠
❖ unit equivalent with drops as its one of its dimension: 20𝑑𝑟𝑜𝑝𝑠 = 𝑚𝑙
➢ Write the Unit Equivalent as conversion factor with it numerator unit similar to that of the wanted Quantity:
➢
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
➢ Add the subsequent conversion factors so that their numerator dimension is similar to the denominator unit of the
preceding conversion factor. This will allow Unwanted quantity to cancel each other leaving only the Wanted dimensions.
➢
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×⇗
𝑚𝑙
➢ This process continue until all the Unwanted units are cancelled out leaving only the desire(Wanted dimension ie the
Dimensions of Wanted Quantity)
➢ Multiple the numerators:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
5𝑈
×
1𝑈
1000𝑚𝐼𝑈
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
=
300000𝑑𝑟𝑜𝑝𝑠
➢ Multiple the denominators: :
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
5𝑈
×
1𝑈
1000𝑚𝐼𝑈
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
=
300000𝑑𝑟𝑜𝑝𝑠
5000𝑚𝑖𝑛
➢ Divide the results: :
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
5𝑈
×
1𝑈
1000𝑚𝐼𝑈
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
=
300000𝑑𝑟𝑜𝑝𝑠
5000𝑚𝑖𝑛
= 60
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
DR MUSA 20
23. SEQUENTIAL METHOD 2
• Identify the Wanted Quantity and Unit (unit of measure)↔
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
• Identify the Unit Equivalencies and Conversion Factors write them as Unit equivalencies
➢ 5𝑈 = 500𝑚𝑙; 1U = 1000mU; 20drops = ml; 1hr = 60min; 30mIU = min
• Identify the Given Quantity with Unit↔
30𝑚𝑈
𝑚𝑖𝑛
• Create a unit paths
➢ Write dimensions of wanted quantity(unit of measure) as Conversion factor to begin the equation:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
➢ Write an equal sign:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
➢ Write the given Quantity as Conversion Factor:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
30𝑚𝑈
𝑚𝑖𝑛
➢ Add the rest of Unit Equivalencies as multiples of Conversion factors so that one of the Unwanted Unit of
the preceding variable is cancelled out by an Unwanted unit of the succeeding variable:
➢
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
30𝑚𝑈
𝑚𝑖𝑛
×
1𝑈
1000𝑚𝑈
×
500𝑚𝑙
5𝑈
×
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
➢ This process continue until all the Unwanted units are cancelled out leaving only the desire(Wanted
dimension ie the Dimensions of Wanted Quantity)
➢ Multiple the numerators:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
1𝑈
1000𝑚𝐼𝑈
×
500𝑚𝑙
5𝑈
×
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
=
300000𝑑𝑟𝑜𝑝𝑠
➢ Multiple the denominators:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
1𝑈
1000𝑚𝐼𝑈
×
500𝑚𝑙
5𝑈
×
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
=
300000𝑑𝑟𝑜𝑝𝑠
5000𝑚𝑖𝑛
➢ Divide the results:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
1𝑈
1000𝑚𝐼𝑈
×
500𝑚𝑙
5𝑈
×
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
=
300000𝑑𝑟𝑜𝑝𝑠
5000𝑚𝑖𝑛
= 60
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
DR MUSA 23
26. RANDOM METHOD 1
• Identify the Wanted Quantity and Unit(unit of measure)↔
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
• Identify the Unit Equivalencies and Conversion Factors write them as Unit equivalents
➢ 5𝑈 = 500𝑚𝑙; 1U = 1000mU; 20drops = ml; 1hr = 60min; 30mIU = min
• Identify the Given Quantity with Unit↔
30𝑚𝑈
𝑚𝑖𝑛
• Create a unit paths
➢ Write dimensions of wanted quantity (unit of measure)as Conversion factor to begin the equation:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
➢ Write an equal sign:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
➢ Write the given Quantity as Conversion Factor:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
30𝑚𝑈
𝑚𝑖𝑛
➢ Add the rest of Unit Equivalencies as multiples of Conversion factors without order so that one of the
Unwanted Unit are cancelled and only the desire or wanted dimensions are left:
➢
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
500𝑚𝑙
5𝑈
×
1𝑈
1000𝑚𝐼𝑈
×
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
➢ Multiple the numerators:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
500𝑚𝑙
5𝑈
×
1𝑈
1000𝑚𝐼𝑈
×
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
=
300000𝑑𝑟𝑜𝑝𝑠
➢ Multiple the denominators:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
500𝑚𝑙
5𝑈
×
1𝑈
1000𝑚𝐼𝑈
×
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
=
300000𝑑𝑟𝑜𝑝𝑠
5000𝑚𝑖𝑛
➢ Divide the results:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
500𝑚𝑙
5𝑈
×
1𝑈
1000𝑚𝐼𝑈
×
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
=
300000𝑑𝑟𝑜𝑝𝑠
5000𝑚𝑖𝑛
= 60
𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
DR MUSA 26
27. RANDOM METHOD 2
• Identify the Wanted Quantity and Unit(unit of measure)↔
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
• Identify the Unit Equivalencies and Conversion Factors write them as Unit equivalents
➢ 5𝑈 = 500𝑚𝑙; 1U = 1000mU; 20drops = ml; 1hr = 60min; 30mIU = min
• Identify unit equivalent that have dimension similar to the numerator of the wanted
Quantity with Unit↔ 20𝑑𝑟𝑜𝑝𝑠 = 𝑚𝑙;
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
• Create a unit paths
➢ Write dimensions of wanted quantity (unit of measure) as Conversion factor to begin the equation:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
➢ Write an equal sign:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
➢ Write the given Quantity as Conversion Factor:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
➢ Add the rest of Unit Equivalent as multiples of Conversion factors without order so that one of the
Unwanted Unit are cancelled and only the desire or wanted dimensions are left:
➢
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
500𝑚𝑙
5𝑈
×
1𝑈
1000𝑚𝐼𝑈
➢ Multiple the numerators:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
500𝑚𝑙
5𝑈
×
1𝑈
1000𝑚𝐼𝑈
=
300000𝑑𝑟𝑜𝑝𝑠
➢ Multiple the denominators:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
500𝑚𝑙
5𝑈
×
1𝑈
1000𝑚𝐼𝑈
=
300000𝑑𝑟𝑜𝑝𝑠
5000𝑚𝑖𝑛
➢ Divide the results:
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
500𝑚𝑙
5𝑈
×
1𝑈
1000𝑚𝐼𝑈
=
300000𝑑𝑟𝑜𝑝𝑠
5000𝑚𝑖𝑛
= 60
𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
DR MUSA 27
30. RANDOM METHOD 2a
• Wanted quantity↔ 𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑒
➢ Dimensions of Wanted Quantity(unit of measure)↔
𝑚𝑙
ℎ𝑟
• Unit Equivalencies(Conversion Factors)
➢ 1𝑢𝑛𝑖𝑡 = 1000𝑚𝐼𝑈
➢ 500𝑚𝑙 = 5𝑢𝑛𝑖𝑡
➢ 60𝑚𝑖𝑛 = 1ℎ𝑟
➢ 5𝑚𝐼𝑈 = 𝑚𝑖𝑛
• Unit equivalent with dimensions similar to numerator of the wanted
Quantity↔ 500𝑚𝑙 = 5𝑢𝑛𝑖𝑡:
500𝑚𝑙
5𝑢𝑛𝑖𝑡
• Unit Path Way
➢ =
𝑚𝑙
ℎ𝑟
➢
500𝑚𝑙
5𝑢𝑛𝑖𝑡
=
𝑚𝑙
ℎ𝑟
➢
500𝑚𝑙
5𝑢𝑛𝑖𝑡
×
5𝑚𝐼𝑈
𝑚𝑖𝑛
=
𝑚𝑙
ℎ𝑟
➢
500𝑚𝑙
5𝑢𝑛𝑖𝑡
×
5𝑚𝐼𝑈
𝑚𝑖𝑛
×
1𝑢𝑛𝑖𝑡
1000𝑚𝐼𝑈
=
𝑚𝑙
ℎ𝑟
➢
500𝑚𝑙
5𝑢𝑛𝑖𝑡
×
5𝑚𝐼𝑈
𝑚𝑖𝑛
×
1𝑢𝑛𝑖𝑡
1000𝑚𝐼𝑈
×
60𝑚𝑖𝑛
ℎ𝑟
=
𝑚𝑙
ℎ𝑟
➢
500𝑚𝑙
5𝑢𝑛𝑖𝑡
×
5𝑚𝐼𝑈
min
×
1𝑢𝑛𝑖𝑡
1000𝑚𝐼𝑈
×
60𝑚𝑖𝑛
ℎ𝑟
=
150000𝑚𝑙
5000ℎ𝑟
=
30𝑚𝑙
ℎ𝑟
DR MUSA 30
31. RANDOM METHOD 2b
• Wanted quantity↔ 𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑒
➢ Dimensions of Wanted Quantity(unit of measure)↔
𝑚𝑙
ℎ𝑟
• Unit Equivalencies(Conversion Factors)
➢ 1𝑢𝑛𝑖𝑡 = 1000𝑚𝐼𝑈
➢ 500𝑚𝑙 = 5𝑢𝑛𝑖𝑡
➢ 60𝑚𝑖𝑛 = 1ℎ𝑟
➢ 5𝑚𝐼𝑈 = 𝑚𝑖𝑛
• Unit equivalent with dimensions similar to numerator of the wanted
Quantity↔ 500𝑚𝑙 = 5𝑢𝑛𝑖𝑡: 𝑖𝑒
500𝑚𝑙
5𝑢𝑛𝑖𝑡
• Unit Path Way
➢
𝑚𝑙
ℎ𝑟
=
➢
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
5𝑢𝑛𝑖𝑡
➢
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
5𝑢𝑛𝑖𝑡
×
5𝑚𝐼𝑈
𝑚𝑖𝑛
➢
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
5𝑢𝑛𝑖𝑡
×
5𝑚𝐼𝑈
𝑚𝑖𝑛
×
1𝑢𝑛𝑖𝑡
1000𝑚𝐼𝑈
➢
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
5𝑢𝑛𝑖𝑡
×
5𝑚𝐼𝑈
𝑚𝑖𝑛
×
1𝑢𝑛𝑖𝑡
1000𝑚𝐼𝑈
×
60𝑚𝑖𝑛
ℎ𝑟
➢
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
5𝑢𝑛𝑖𝑡
×
5𝑚𝐼𝑈
min
×
1𝑢𝑛𝑖𝑡
1000𝑚𝐼𝑈
×
60𝑚𝑖𝑛
ℎ𝑟
=
150000𝑚𝑙
5000ℎ𝑟
=
30𝑚𝑙
ℎ𝑟
DR MUSA 31
32. USING DIMENSIONAL ANALYSIS TO
CALCULATE IV FLOW RATES
• Dimensional analysis is another format for setting up
problems to calculate drug dosages. The advantage of
dimensional analysis is that only one equation is
needed. This is true even if the information supplied
indicates a need to convert to like units before setting
up the proportion to perform the actual calculation of
the amount of medication to be given to the patient.
• The dimensional analysis method can also be used to
calculate intravenous (IV) flow rates. The following
formulas demonstrate how to calculate drops per
minute (gtt/min) and milliliters per hour (mL/h).
DR MUSA 32
33. • EXAMPLE 1: The physician orders gentamicin 80 mg in 100 mL D5W to be
infused over 1 hour. The tubing drop factor is 60 gtt/mL. How many drops
per minute should be given to infuse the gentamicin over 1 hour
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
60𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
100𝑚𝑙
1ℎ𝑟
×
1ℎ𝑟
60𝑚𝑖𝑛
• =
6000𝑑𝑟𝑜𝑝𝑠
60𝑚𝑖𝑛
• = Τ
100𝑑𝑟𝑜𝑝𝑠 𝑚𝑖𝑛
• EXAMPLE 2: The physician orders cefuroxime 1 g in 50 mL of normal saline
solution (NS) to be infused over 30 minutes. The tubing drop factor is 60
gtt/mL. How many drops per minute should be given to infuse the total
amount of cefuroxime over 30 minutes?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
60𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
50𝑚𝑙
30𝑚𝑖𝑛
• =
3000𝑑𝑟𝑜𝑝𝑠
30𝑚𝑖𝑛
• = Τ
100𝑑𝑟𝑜𝑝𝑠 𝑚𝑖𝑛
DR MUSA 33
34. • EXAMPLE 3 : Hespan 500 mL is ordered to be infused over 3 hours. The
drop factor is 15 gtt/mL. How many drops per minute should be given to
infuse the total amount of Hespan over 3 hours?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
15𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
3ℎ𝑟
×
1ℎ𝑟
60𝑚𝑖𝑛
• =
7500𝑑𝑟𝑜𝑝𝑠
180𝑚𝑖𝑛
• = Τ
42𝑑𝑟𝑜𝑝𝑠 𝑚𝑖𝑛
• EXAMPLE 4: 1000 mL of dextrose 5% in water (D5W) is ordered to be
infused over 5 hours. The drop factor is 10 gtt/mL. How many drops per
minute should be given to infuse the 1000 mL over 5 hours
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
10𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
1000𝑚𝑙
5ℎ𝑟
×
1ℎ𝑟
60𝑚𝑖𝑛
• =
10000𝑑𝑟𝑜𝑝𝑠
300𝑚𝑖𝑛
• = Τ
33𝑑𝑟𝑜𝑝𝑠 𝑚𝑖𝑛
DR MUSA 34
35. • EXAMPLE 5: The order states Augmentin 500 mg po daily. The drug is
supplied in 250-mg tablets. How many tablets will the nurse administer?
Tablet =
𝑡𝑎𝑏𝑙𝑒𝑡
250𝑚𝑔
×
500𝑚𝑔
• =
500𝑡𝑎𝑏𝑙𝑒𝑡𝑠
250
• = 2𝑡𝑎𝑏𝑙𝑒𝑡𝑠
• EXAMPLE 6: A patient has an order for enalaprilat 0.625 mg daily IVPB
(intravenous piggyback). The enalaprilat is diluted in 50 mL of D5W
(dextrose 5% in water) and is to be infused over 20 minutes. The tubing
drop factor is 60 gtt/mL. At what rate, in drops per minute, should the
IVPB be programmed?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
60𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
50𝑚𝑙
.20𝑚𝑖𝑛
• =
3000𝑑𝑟𝑜𝑝𝑠
20𝑚𝑖𝑛
• = Τ
150𝑑𝑟𝑜𝑝𝑠 𝑚𝑖𝑛
DR MUSA 35
36. • EXAMPLE 7: A patient has an order for regular insulin IV at a rate of 5
units/h. The concentration is insulin 100 units/100 mL 0.9% NS. At what
rate, in milliliters per hour, should the IV pump be programmed?
•
𝑚𝑙
ℎ𝑟
=
100𝑚𝑙
100𝑢𝑛𝑖𝑡
×
5𝑢𝑛𝑖𝑡
ℎ𝑟
• =
500𝑚𝑙
100ℎ𝑟
• = Τ
5𝑚𝑙 ℎ𝑟
• EXAMPLE 8: A patient with a femoral thrombus has an order for heparin
IV at 1200 units/h. The concentration is heparin 20,000 units in 250 mL of
D5W. At what rate, in milliliters per hour, should the IV pump be
programmed?
•
𝑚𝑙
ℎ𝑟
=
250𝑚𝑙
20000𝑢𝑛𝑖𝑡
×
1200𝑢𝑛𝑖𝑡
ℎ𝑟
• =
300000𝑚𝑙
20000ℎ𝑟
• = Τ
15𝑚𝑙 ℎ𝑟
DR MUSA 36
37. • EXAMPLE 9: Lidocaine 1 g has been added to 500
mL of D5W. The order states to infuse the
lidocaine at 2 mg/min. The nurse needs to
calculate the rate, in milliliters per hour, at which
the IV pump should be set (rounded to the
nearest tenth
•
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
1𝑔
×
1𝑔
1000𝑚𝑔
×
2𝑚𝑔
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
30000𝑚𝑙
1000ℎ𝑟
• = Τ
30𝑚𝑙 ℎ𝑟
DR MUSA 37
38. • EXAMPLE 10: The order is to infuse the nitroglycerin at 5 mcg/min; 50 mg
of nitroglycerin has been added to 500 mL of 0.9% NS. The nurse needs to
calculate the rate, in milliliters per hour, at which to set the IV pump.
•
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
50𝑚𝑔
×
1𝑚𝑔
1000𝑚𝑐𝑔
×
5𝑚𝑐𝑔
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
150000𝑚𝑙
50000ℎ𝑟
• = Τ
3𝑚𝑙 ℎ𝑟
• EXAMPLE 11: The order is to begin a dopamine infusion at 3 mcg/kg/min;
800 mg of dopamine is added to 250 mL of 0.9% NS. The patient’s weight
is 70 kg. The nurse needs to calculate the rate, in milliliters per hour, at
which to set the IV pump.
•
𝑚𝑙
ℎ𝑟
=
250𝑚𝑙
800𝑚𝑔
×
1𝑚𝑔
1000𝑚𝑐𝑔
×
3𝑚𝑐𝑔
𝑘𝑔/𝑚𝑖𝑛
×
70𝑘𝑔
×
60𝑚𝑖𝑛
ℎ𝑟
• =
3150000𝑚𝑙
800000ℎ𝑟
• = Τ
4𝑚𝑙 ℎ𝑟
DR MUSA 38
39. USING DIMENSIONAL ANALYSIS TO
CALCULATE PEDIATRIC DOSAGES
• Pediatric Dosage Calculations
• EXAMPLE 12: The physician orders Benadryl 12.5
mg po q4-6 h prn for itching. The nurse has
available Benadryl 25 mg/5 mL. How many
milliliters are needed to administer 12.5 mg?
• ml =
5𝑚𝑙
25𝑚𝑔
×
12.5𝑚𝑔
• =
62.5𝑚𝑙
25
• = 2.5𝑚𝑙
DR MUSA 39
40. Calculating the Single or Individual
Dose (Milligrams/Dose)
• Medications such as acetaminophen and ibuprofen are administered as a single dose. This means that each time
the infant or child receives the medication, it is calculated in a single or individual dose based on the kilogram
weight. Most of the medications prescribed in this manner are prn medications, which are given as needed for
relief of symptoms such as pain, nausea, and fever. Again, the manufacturer of the drug has established an S&T
dosage or range. The nurse is responsible for administering the single dose that is S&T. Therefore it is helpful for
the nurse to know how the ordered dose is derived. To determine the correct single dose for the child, you must
calculate the correct dose. A systematic approach is helpful in determining the S&T dose range: • Change the
child’s weight in pounds to kilograms.
• Find the recommended dosage in a reliable source.
• Multiply the kilogram weight by the recommended dose(s).
• The answer is the individual or single dose (mg/dose) of medication to be given each time the child receives the
medication.
• EXAMPLE : A child weighs 22 lb. The child needs acetaminophen for pain and fever
• EXAMPLE: Calculate the safe and therapeutic (S&T) dose range of ibuprofen for a child who weighs 36 lb.
Ibuprofen is available 100 mg/5 mL. How many milliliters would you administer for the ordered dose to be S&T?
The recommended S&T range is 5 to 10 mg/kg/dose q6-8 h.
• 𝑚𝑖𝑛𝑖𝑚𝑢𝑚 𝑑𝑜𝑠𝑒 =
𝑚𝑙
𝑑𝑜𝑠𝑒
=
5𝑚𝑙
100𝑚𝑔
×
5𝑚𝑔
𝑘𝑔/𝑑𝑜𝑠𝑒
×
1𝑘𝑔
2.2𝐼𝑏
×
36𝐼𝑏
• =
900𝑚𝑙
220𝑑𝑜𝑠𝑒
• Τ
4.1𝑚𝑙 𝑑𝑜𝑠𝑒
• 𝑚𝑎𝑥𝑖𝑚𝑢𝑛 𝑑𝑜𝑠𝑒 =
5𝑚𝑙
100𝑚𝑔
×
10𝑚𝑔
𝑘𝑔/𝑑𝑜𝑠𝑒
×
1𝑘𝑔
2.2𝐼𝑏
×
36𝐼𝑏
• =
1800𝑚𝑙
220𝑑𝑜𝑠𝑒
• = Τ
8.2𝑚𝑙 𝑑𝑜𝑠𝑒
DR MUSA 40
41. DETERMINE WHETHER THE PRESCRIBED DOSE IS SAFE AND
THERAPEUTIC (MILLIGRAMS/KILOGRAM/DOSE)
• This method will determine whether the child is receiving an S&T dosage of the
drug that is prescribed by the physician. The nurse must determine whether the
ordered dose is within the recommended range. Even though the physician has
prescribed the medication to be given, it is the nurse’s responsibility to determine
whether the dose is S&T to administer to the child. This is done by dividing the
ordered dosage by the child’s weight in kilograms (mg/kg/dose). A systematic
approach is needed.
• Obtain the child’s weight in kilograms.
• Obtain the ordered dosage.
• Divide the ordered dose by the child’s weight.
• The answer is the mg/kg/dose (for each dose administered).
• Check your drug book to determine whether the ordered dose is S&T (in the
recommended dosage range).
• EXAMPLE: The doctor has ordered 210 mg of acetaminophen q4–6 h for pain and
fever for a postoperative child. The child weighs 39 lb. The recommended dose
range for acetaminophen is 10 to 15 mg/kg/dose q4–6 h. Acetaminophen is
supplied as 160 mg/5 mL. Is the ordered dose S&T to administer? If the dose
ordered is S&T to administer, how many milliliters will be needed?
DR MUSA 41
42. CALCULATE THE 24-HOUR DOSAGE
(RANGES)
• Many drugs are calculated based on the recommended
24-hour dose, then divided into single doses to be
given every 12, 8, 6, or 4 hours or as recommended by
the drug manufacturers. These divided time schedules
vary, and the physician, nurse practitioner, or
physician’s assistant will order the medication based on
the recommended schedules. Antibiotics especially are
given this way. Additionally, an antibiotic may be given
in dosages or ranges that have been found to be
effective for the child’s diagnosis. The physician
chooses how often the medication is to be delivered.
An example of an antibiotic with many dosing choices
is ampicillin.
DR MUSA 42
43. • Recommended dosages for ampicillin may be any of the following: ,2 kg 50 to 100
mg/kg/24 h/q8 h .2 kg 100 to 200 mg/kg/24 h/q8 h Mild to moderate infection
100 to 200 mg/kg/24 h/q6 h Severe infection 200 to 400 mg/kg/24 h/q4–6 h The
physician must determine the dosage to be given to the infant or child. If an infant
or child is diagnosed with otitis media (OM), then the physician may choose the
dosage of antibiotic in the mild to moderate range. However, if an infant is
admitted with a diagnosis of fever of undetermined origin, sepsis, or meningitis,
then the physician may decide to prescribe a larger dosage of the antibiotic, as in
the severe infection range. Knowing the diagnosis is helpful in determining
whether the infant or child will be receiving S&T dosages of antibiotics. Nurses
who administer antibiotics or anti infectives can learn how to determine the doses
needed for the patient. However, only the physician, advanced practice nurse, or
physician assistant can prescribe and order the infant’s or child’s medications.
EXAMPLE 1: An infant is admitted to the hospital to rule out sepsis. The infant
weighs 8 lb. Ampicillin is prescribed. Calculate an S&T 24-hour dosage range for
this infant with a possible severe infection
• EXAMPLE : The child weighs 35 lb and is diagnosed with OM. The physician
prescribes amoxicillin. Calculate an S&T 24-hour dosage range for this patient.
DR MUSA 43
44. CALCULATE THE INDIVIDUAL DOSE OR SINGLE DOSE
(MILLIGRAMS/KILOGRAM/24 HOURS DIVIDED)
• The physician will now determine how often the antibiotic will be
administered as a single or individual dose. First determine the 24-
hour dosage range. Then divide the 24-hour dosage into single
doses (the number of times per day the medication is to be given).
• This is the individual dose each time the patient receives the
medication.
• These times are established by the drug companies (e.g., q4 h, q6 h,
q8 h, q12 h, or every day).
• As long as the dose does not exceed the maximum dose established
in 24 hours and the dose does not exceed the adult dose, then it
can be given safely.
• The physician will decide how often the medication is to be given
DR MUSA 44
45. • EXAMPLE : A child weighs 22 lb. The physician prescribes ampicillin 100 to 200 mg/kg/ 24 h divided
q6 h. Calculate the individual dose for ampicillin.
•
𝑚𝑔
𝑑𝑜𝑠𝑒
=
200𝑚𝑔
𝑘𝑔/24ℎ𝑟𝑠
×
1𝑘𝑔
2.2𝐼𝑏
×
22𝐼𝑏
×
6ℎ𝑟𝑠
𝑑𝑜𝑠𝑒
• =
26400𝑚𝑔
52.8𝑑𝑜𝑠𝑒
• = Τ
500𝑚𝑔 𝑑𝑜𝑠𝑒
• EXAMPLE : A child weighs 60 lb. The physician orders cefuroxime. The recommended dosage is 75
to 100 mg/kg/24 h q8 h. What is the S&T dosage or range for this child?
•
𝑚𝑔
𝑑𝑜𝑠𝑒
=
75𝑚𝑔
𝑘𝑔/24ℎ𝑟
×
1𝑘𝑔
2.2𝐼𝑏
×
60𝐼𝑏
×
8ℎ𝑟
𝑑𝑜𝑠𝑒
• =
36000𝑚𝑔
52.8𝑑𝑜𝑠𝑒
• = Τ
682𝑚𝑔 𝑑𝑜𝑠𝑒
•
𝑚𝑔
𝑑𝑜𝑠𝑒
=
100𝑚𝑔
𝑘𝑔/24ℎ𝑟𝑠
×
1𝑘𝑔
2.2𝐼𝑏
×
60𝐼𝑏
×
8ℎ𝑟
𝑑𝑜𝑠𝑒
• =
48000𝑚𝑔
52.8𝑑𝑜𝑠𝑒
• = Τ
909𝑚𝑔 𝑑𝑜𝑠𝑒
DR MUSA 45
46. Calculate the 24-Hour Dosage (Ranges)
• EXAMPLE: An infant is admitted to the
hospital to rule out sepsis. The infant weighs 8
lb. Ampicillin is prescribed. Calculate the S&T
24-hour dosage range for this infant with a
possible severe infection. The recommended
dose is 200 to 400 mg/kg/ 24 h. An infant
weighing 8 lb can receive 720 to 1440 mg
ampicillin in a 24-hour period.
•
𝑚𝑔
24ℎ𝑟
=
200𝑚𝑔
𝑘𝑔/24ℎ𝑟
×
1𝑘𝑔
2.2𝐼𝑏
×
8𝐼𝑏
DR MUSA 46
47. DETERMINE THE ACTUAL MILLIGRAMS/KILOGRAM/ 24 HOURS OR
DOSE/KILOGRAM/24 HOURS
• The nurse must understand how to prove that the patient is actually receiving an
S&T dosage or range. When a physician prescribes a medication, he or she has a
range from which to choose. As a nurse, you need to check to see whether the
medication falls within the recommended dosage or range. This is important
because medication doses are patient–weight specific. Determining the actual
milligrams per kilogram per 24 hours that the patient is receiving is done simply by
dividing the actual milligrams to be given in 24 hours by the patient’s weight.
Remember that the physician has already prescribed the medication based on the
recommended dose in milligrams per kilogram per 24 hours. For nurses, knowing
how to prove S&T dosing is critical. To determine (prove) whether the patient is
receiving an S&T dosage, the nurse will need to:
• Obtain the infant’s or child’s kilogram weight.
• Obtain the medication order.
• Determine the amount of medication the child will receive in the 24-hour period
(the 24-hour dosage).
• Divide the prescribed 24-hour dosage by the patient’s weight.
• Compare the ordered dosage with the recommended dosage. There is no need to
calculate a dosage range, since the physician has already done this
DR MUSA 47
48. • EXAMPLE : A 4-year-old child is receiving
vancomycin 220 mg q6 h IV via syringe pump. She
weighs 48 lb. Recommended dosage is 40 to 60
mg/kg/24 h q6 h. How many milligrams per
kilogram per 24 hours is this child receiving? Is
the ordered dosage S&T?
• EXAMPLE : A 75-lb patient is receiving 900 mg of
ampicillin IVPB q6 h. How many milligrams per
kilogram per 24 hours is the patient receiving? Is
the dosage S&T?
DR MUSA 48
49. CALCULATING PEDIATRIC IV
SOLUTIONS
• Pediatric patients require smaller volumes of IV fluids and medications than adults.
An IV pump, a buretrol (soluset), or both may be used for the pediatric patient.
Each facility has guidelines for preparing and administering IV solutions and
medications to the pediatric patient. Also, for a pediatric patient, IV tubing with a
drop factor of 60 gtt/mL is usually recommended. The concentration of the IV
medication is also an important factor in medication administration.
Administering a medication with a higher concentration than recommended is
avoided because of the vein irritation that can result.
• EXAMPLE : Infuse 100 mL of 0.9% NS over 5 hours to a 6-month-old child. How
many milliliters per hour should the IV pump be programmed for?
•
𝑚𝑙
ℎ𝑟
=
100𝑚𝑙
5ℎ𝑟𝑠
• Τ
= 20𝑚𝑙 ℎ𝑟
• EXAMPLE : Infuse 150 mL of D5LR over 3 hours to a 3-year-old child. How many
milliliters per hour should the IV pump be programmed for?
•
𝑚𝑙
ℎ𝑟
=
150𝑚𝑙
3ℎ𝑟
• Τ
= 50𝑚𝑙 ℎ𝑟
DR MUSA 49
50. • EXAMPLE : Infuse 200 mL lactated Ringer’s solution (LR) over 4 hours to
an 8-year-old child. The tubing drop factor is 60 gtt/mL. How many drops
per minute of LR should be infused?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
60𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
200𝑚𝑙
4ℎ𝑟
×
1ℎ𝑟
60𝑚𝑖𝑛
• =
12000𝑑𝑟𝑜𝑝𝑠
240𝑚𝑖𝑛
• = Τ
50𝑑𝑟𝑜𝑝𝑠 𝑚𝑖𝑛
• EXAMPLE : Infuse 500 mL of D5W over 8 hours to a 14-year-old child. The
tubing drop factor is 60 gtt/mL. How many drops per minute of D5W
should be infused?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
60𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
8ℎ𝑟𝑠
×
1ℎ𝑟
60𝑚𝑖𝑛
• =
30000𝑑𝑟𝑜𝑝𝑠
480𝑚𝑖𝑛
• = Τ
63𝑑𝑟𝑜𝑝𝑠 𝑚𝑖𝑛
DR MUSA 50
51. ADMINISTRATION OF IV MEDICATIONS
TO PEDIATRIC PATIENTS
• The formulas to calculate the administration rate of IV
medications to pediatric patients are not different
from those used for adults. The difference in
administration of medications to a pediatric patient
lies in the volume of solution used. Pediatric patients
require a smaller volume of IV solutions; therefore care
must be taken to give the medication at the
recommended infusion concentration. Using a
concentration that is higher than recommended may
result in vein irritation and phlebitis. Unit policies and
IV drug books provide the guidelines needed for
appropriate concentration of IV medications for the
pediatric patient.
DR MUSA 51
52. • EXAMPLE : An 18-month-old child has Ancef 450 mg q4 h
IVPB over 15 minutes ordered. The child weighs 19 kg. The
maximum recommended infusion concentration is 50
mg/mL. The vial of medication has a concentration of Ancef
250 mg/mL. How many milliliters of medication will provide
450 mg? _______ How many milliliters of IV solution need
to be added to the medication to equal the recommended
final concentration? _______ How many milliliters per hour
should the IV pump be programmed for? _______
• a. Calculate volume of medication to withdraw from the
vial
• b. Calculate the volume of IV solution to provide the
recommended final concentration
DR MUSA 52
53. • EXAMPLE : A child weighing 30 kg has an order for nafcillin
850 mg IVPB q6 h over 10 minutes. The nafcillin vial gives a
concentration of 250 mg/mL. The recommended infusion
concentration of nafcillin is 100 mg/mL. How many
milliliters of medication will provide 850 mg of nafcillin?
_______ How many milliliters of IV solution need to be
added to the medication to equal the recommended final
concentration? _______ How many drops per minute
should the IVPB be programmed for? _______
• a. Calculate the volume of medication to withdraw from
the vial.
• b. Calculate the volume of IV solution to provide the
recommended final concentration
DR MUSA 53
54. Calculation of Dosage Based on Body
Surface Area
• The calculation of dosage may be based on BSA. The BSA method
provides a means of converting an adult dosage to a safe pediatric
dosage. There are three steps to the calculation with this method.
• Determine the child’s weight in kilograms.
• Calculate the BSA in square meters. The formula for this calculation
is as follows:
• 𝐵𝑆𝐴 𝑖𝑛 𝑠𝑞𝑢𝑎𝑟𝑒 𝑚𝑒𝑡𝑒𝑟 =
4𝑊(𝑐ℎ𝑖𝑙𝑑′𝑠 𝑤𝑒𝑖𝑔ℎ𝑡 𝑖𝑛 𝑘𝑖𝑙𝑜𝑔𝑟𝑎𝑚)+7
𝑊(𝑐ℎ𝑖𝑙𝑑′𝑠𝑤𝑒𝑖𝑔ℎ𝑡 𝑖𝑛 𝑘𝑖𝑙𝑜𝑔𝑟𝑎𝑚)+90
• Calculate the pediatric dosage using the following formula. The
formula is based on the premise that an adult who weighs 140 lb
has a BSA of 1.7 m2.
• 𝑐ℎ𝑖𝑙𝑑′
𝑠 𝑑𝑜𝑠𝑒 =
𝐵𝑆𝐴 𝑖𝑛 𝑠𝑞𝑢𝑎𝑟𝑒 𝑚𝑒𝑡𝑒𝑟
1.7
× 𝑎𝑑𝑢𝑙𝑡 𝑑𝑜𝑠𝑒
• EXAMPLE: The child weighs 24 lb and the adult dose is 100 mg
DR MUSA 54
55. USING DIMENSIONAL ANALYSIS TO
CALCULATE OBSTETRIC DOSAGES
• IV Administration of Medications by Milliunits/Min
• EXAMPLE : The physician has ordered 1000 mL D5W with 10 units oxytocin intravenously. Begin at 1 mU/min and
then increase by 1 mU/min every 30 minutes until regular contractions occur. The maximum dose is 20 mU/min.
• a. Calculate the IV rate (mL/h) for the beginning infusion.
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝑢𝑛𝑖𝑡
×
1𝑢𝑛𝑖𝑡
1000𝑚𝑈
×
1𝑚𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
60000𝑚𝑙
10000ℎ𝑟
• = Τ
6𝑚𝑙 ℎ𝑟
• B. Calculate the IV Drip rate (drops/min) for the beginning infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
1000𝑚𝑙
10𝑈
×
1𝑈
1000𝑚𝐼𝑈
×
1𝑚𝐼𝑈
𝑚𝑖𝑛
• =
20000𝑚𝑙
10000𝑚𝑖𝑛
• = Τ
2𝑚𝑙
𝑚𝑖𝑛
• C. Calculate the maximum IV rate the Pitocin infusion may be set for
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝑢𝑛𝑖𝑡
×
1𝑢𝑛𝑖𝑡
1000𝑚𝑈
×
20𝑚𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
1200000𝑚𝑙
10000ℎ𝑟
• = Τ
12𝑚𝑙 ℎ𝑟
• D. Calculate the maximum IV rate the Pitocin infusion may be set for
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
1000𝑚𝑙
10𝑈
×
1𝑈
1000𝑚𝐼𝑈
×
20𝑚𝐼𝑈
𝑚𝑖𝑛
DR MUSA 55
56. • EXAMPLE : The physician has ordered 500 mL D5W with 10 units oxytocin
intravenously. Begin at 2.5 mU/min and then increase by 2.5 mU/min
every 30 minutes until active labor is achieved. Maximum dose is 28
mU/min
• a. Calculate the IV rate (mL/h) for the beginning infusion
•
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
10𝑢𝑛𝑖𝑡
×
1𝑢𝑛𝑖𝑡
1000𝑚𝑈
×
2.5𝑚𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
75000𝑚𝑙
10000ℎ𝑟
• = Τ
7.5𝑚𝑙 ℎ𝑟
• b. Calculate the maximum IV rate the Pitocin infusion may be set for.
•
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
10𝑢𝑛𝑖𝑡
×
1𝑢𝑛𝑖𝑡
1000𝑚𝑈
×
28𝑚𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
840000𝑚𝑙
10000ℎ𝑟
• = Τ
84𝑚𝑙 ℎ𝑟
DR MUSA 56
57. • EXAMPLE : The physician has ordered 1000 mL D5W with 20 units
oxytocin intravenously. Begin at 5 mU/min and then increase by 5 mU/min
every 30 minutes until regular contractions occur. The maximum dose is
30 mU/min
• a. Calculate the IV rate (mL/h) for the beginning infusion.
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
20𝑢𝑛𝑖𝑡
×
1𝑢𝑛𝑖𝑡
1000𝑚𝑈
×
5𝑚𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
300000𝑚𝑙
20000ℎ𝑟
• = Τ
150𝑚𝑙 ℎ𝑟
• b. Calculate the maximum IV rate the Pitocin infusion may be set for.
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
20𝑢𝑛𝑖𝑡
×
1𝑢𝑛𝑖𝑡
1000𝑚𝑈
×
30𝑚𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
1800000𝑚𝑙
20000ℎ𝑟
• = Τ
90𝑚𝑙 ℎ𝑟
DR MUSA 57
58. IV Administration of Medications by Milligrams/Min
• EXAMPLE : The physician has ordered 1000 mL lactated Ringer’s
with 20 g magnesium sulfate. You are to administer a bolus with 4
g/30 min, then maintain a continuous infusion at 2 g/h.
• a. Calculate the IV rate (mL/h) for the bolus order
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
20𝑔
×
4𝑔
30𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
240000𝑚𝑙
600ℎ𝑟
• = Τ
400𝑚𝑙 ℎ𝑟
• b. Calculate the IV rate (mL/h) for the continuous infusion
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
20𝑔
×
2𝑔
ℎ𝑟
• =
2000𝑚𝑙
20ℎ𝑟
• = Τ
100𝑚𝑙 ℎ𝑟
DR MUSA 58
59. • EXAMPLE : The physician has ordered 500 mL lactated Ringer’s with
10 g magnesium sulfate. You are to administer a bolus with 2 g/20
min, then maintain a continuous infusion at 1 g/h.
• a. Calculate the IV rate (mL/h) for the bolus order.
•
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
10𝑔
×
2𝑔
20𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
60000𝑚𝑙
200ℎ𝑟
• = Τ
300𝑚𝑙 ℎ𝑟
• b. Calculate the IV rate (mL/h) for the continuous infusion
•
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
10𝑔
×
1𝑔
ℎ𝑟
• =
500𝑚𝑙
10ℎ𝑟
• = Τ
50𝑚𝑙 ℎ𝑟
DR MUSA 59
60. • EXAMPLE : The physician has ordered 1000 mL lactated Ringer’s
with 10 g magnesium sulfate. You are to administer a bolus with 2
g/30 min, then maintain a continuous infusion at 2 g/h
• a. Calculate the IV rate (mL/hr) for the bolus order
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝑔
×
2𝑔
30𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
120000𝑚𝑙
300ℎ𝑟
• = Τ
400𝑚𝑙 ℎ𝑟
• c. Calculate the IV rate (mL/h) for the continuous infusion.
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝑔
×
2𝑔
ℎ𝑟
• =
2000𝑚𝑙
10ℎ𝑟
• = Τ
200𝑚𝑙 ℎ𝑟
DR MUSA 60
61. • A provider orders melphalan 220mcg/kg/day IV every 12hours for a total
of two doses per day. The patient weighs 65kg how many mcg will the
nurse prepare, for each dose?
•
𝑚𝑐𝑔
𝑑𝑜𝑠𝑒
=
220𝑚𝑐𝑔
𝑘𝑔/𝑑𝑎𝑦
×
65𝑘𝑔
×
𝑑𝑎𝑦
2𝑑𝑜𝑠𝑒
• =
14300𝑚𝑐𝑔
2𝑑𝑜𝑠𝑒𝑠
• = Τ
7150𝑚𝑐𝑔 𝑑𝑜𝑠𝑒
• A provider orders ceftazidime 100mg/kg/day IV to be administered
every8hours for a total of 3 doses each day. The patient weighs 17kg. The
pharmacy provides ceftazidime in vials containing 500mg in 5ml. How
many ml will the nurse draw up into the syringe, for each dose?
•
𝑚𝑙
𝑑𝑜𝑠𝑒
=
5𝑚𝑙
500𝑚𝑔
×
100𝑚𝑔
𝑘𝑔/𝑑𝑎𝑦
×
17𝑘𝑔
×
𝑑𝑎𝑦
3𝑑𝑜𝑠𝑒
• =
8500𝑚𝑙
1500𝑑𝑜𝑠𝑒𝑠
• = Τ
5.67𝑚𝑙 𝑑𝑜𝑠𝑒
DR MUSA 61
62. • Calculate the number of seconds in a century
•
𝑠𝑒𝑐
𝑐𝑒𝑛𝑡𝑢𝑟𝑦
=
60𝑠𝑒𝑐
1𝑚𝑖𝑛
×
60𝑚𝑖𝑛
1ℎ𝑟
×
24ℎ𝑟𝑠
𝑑𝑎𝑦
×
365𝑑𝑎𝑦𝑠
1𝑦𝑟
×
100𝑦𝑟𝑠
1𝑐𝑒𝑛𝑡𝑢𝑟𝑦
DR MUSA 62
63. Obstetric Dosages
• In obstetric nursing, oxytocin (Pitocin) and
magnesium sulfate are commonly used. Oxytocin
is used to either augment or induce labor and
also for postpartum haemorrhage. Magnesium
sulfate is used to prevent seizures in mothers
diagnosed with preeclampsia and is also used “off
label” to control preterm labor contractions. Both
these medications can be titrated, which means
that the medication can be adjusted up and down
based on patient status.
DR MUSA 63
64. Converting percentages to milligrams
• Magnesium sulphate usually prepared as percentages.
• Percentages means out of hundred
• In volume/volume percentages means milliliter/100millitre.
Hence 25% v/v means 25millilitre/100millilitre
• In weight/volume percentage means grams of
solute/100milliliter of solution. Hence 50% w/v means
50grams/100milliliter.
• This implies 50000mg/100ml ie 50mg/ml
• 5% D5W dextrose means 5g/100ml of dextrose solution
• 0.9% NS means 0.9g of NaCl/100ml of NS
• 20% mannitol means 20g/100ml of mannitol solution
DR MUSA 64
65. IV ADMINISTRATION OF MEDICATIONS
BY MILLIUNITS/MINUTE
• EXAMPLE 1: The physician has ordered 1000 mL 5% dextrose in water (D5W) with 10 units IV
oxytocin. Begin at 1 mIU/min and then increase by 1 mIU/min every 30 minutes until regular
contractions occur. Maximum dose is 60 mIU/min.
• What Is the IV Rate (mL/hr) for the Beginning Infusion?
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
1𝑚𝐼𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
60000𝑚𝑙
10000ℎ𝑟
• = Τ
6𝑚𝑙 ℎ𝑟
• What Is the IV Drip Rate (drops/min) for the Beginning Infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
1000𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
1𝑚𝐼𝑈
𝑚𝑖𝑛
• What Is the Maximum IV Rate (ml/hr) the Oxytocin Infusion May Be Set for
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
60𝑚𝐼𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
3600000𝑚𝑙
10000ℎ𝑟
• = Τ
360𝑚𝑙 ℎ𝑟
• What Is the Maximum IV Drip Rate (drops/min) the Oxytocin Infusion May be set for?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛𝑠
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
1000𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
60𝑚𝐼𝑈
𝑚𝑖𝑛
DR MUSA 65
66. • EXAMPLE 2: The physician has ordered 500 mL D5W with 10 units IV oxytocin. Begin at 2.5
mIU/min and then increase by 2.5 mIU/min every 30 minutes until active labor begins. Maximum
dose is 28 mIU/min.
• What Is the IV Rate (mL/hr) for the Beginning Infusion?
•
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
2.5𝑚𝐼𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
60000𝑚𝑙
10000ℎ𝑟
• = Τ
6𝑚𝑙 ℎ𝑟
• What Is the IV Drip Rate (drop/min) for the Beginning Infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
2.5𝑚𝐼𝑈
𝑚𝑖𝑛
• What Is the Maximum IV Rate (ml/hr) the Oxytocin Infusion May Be Set for?
•
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
28𝑚𝐼𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
840000𝑚𝑙
10000ℎ𝑟
• = Τ
84𝑚𝑙 ℎ𝑟
• What Is the Maximum IV Drip Rate (drops/min) the Oxytocin Infusion may be set for?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
28𝑚𝐼𝑈
𝑚𝑖𝑛
DR MUSA 66
67. • EXAMPLE 3: The physician has ordered 1000 mL D5W with 10 units IV oxytocin. Begin at 5 mIU/min
and then increase by 5 mIU/min every 30 minutes until regular contractions occur. Maximum dose
is 30 mIU/min.
• What Is the IV Rate (mL/hr) for the Beginning Infusion?
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
5𝑚𝐼𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
300000𝑚𝑙
10000ℎ𝑟
• = Τ
30𝑚𝑙 ℎ𝑟
• What Is the IV Drip Rate (drops/min) for the Beginning Infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
1000𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
5𝑚𝐼𝑈
𝑚𝑖𝑛
• What Is the Maximum IV Rate (ml/hr) the Oxytocin Infusion May Be Set for?
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
1800000𝑚𝑙
10000ℎ𝑟
• = Τ
180𝑚𝑙 ℎ𝑟
• What Is the Maximum IV Drip Rate (drop/min) the Oxytocin Infusion May Be Set for?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
1000𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
DR MUSA 67
68. • EXAMPLE 3: The physician has ordered 500 mL NS with 10 units IV oxytocin at 30mIU/min to
prevent postpartum haemorrhage.
• What Is the IV Rate (mL/hr) for the Infusion?
•
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
30𝑚𝐼𝑈
1𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
900000𝑚𝑙
10000ℎ𝑟
• = Τ
90𝑚𝑙 ℎ𝑟
• What Is the IV Drip Rate (drops/min) for the Infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
If the dosage changes to 40mIU/min. what is the IV Rate (ml/hr) for the infusion
•
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
40𝑚𝐼𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
1200000𝑚𝑙
10000ℎ𝑟
• = Τ
120𝑚𝑙 ℎ𝑟
• If the dosage changes to 40mIU/min. what is the IV Drip Rate (drops/min) for the infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
10𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
40𝑚𝐼𝑈
𝑚𝑖𝑛
DR MUSA 68
69. IV ADMINISTRATION OF MEDICATIONS
BY MILLIGRAMS/ MINUTE
• EXAMPLE 1: The physician has ordered 1000 mL lactated Ringer’s with 20 g magnesium sulfate IV.
Bolus with 4 g/30 min, then maintain a continuous infusion at 2 g/h.
• What Is the IV Rate (mL/hr) for the Bolus Order?
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
20𝑔
×
4𝑔
30𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
240000𝑚𝑙
600ℎ𝑟
• = Τ
400𝑚𝑙 ℎ𝑟
• What Is the IV Drip Rate (drops/min) for the Bolus Infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
1000𝑚𝑙
20𝑔
×
4𝑔
30𝑚𝑖𝑛
• What Is the IV Rate (mL/hr) for the Continuous Infusion?
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝑔
×
2𝑔
ℎ𝑟
• =
2000𝑚𝑙
10ℎ𝑟
• = Τ
200𝑚𝑙 ℎ𝑟
• What Is the IV Drip Rate (drops/min) for the Continuous Infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
1000𝑚𝑙
20𝑔
×
2𝑔
ℎ𝑟
×
1ℎ𝑟
60𝑚𝑖𝑛
DR MUSA 69
70. • EXAMPLE 2: The physician has ordered 500 mL lactated Ringer’s with 10 g magnesium sulfate IV.
Bolus with 2 g/20 min, then maintain a continuous infusion at 1 g/h.
• What Is the IV Rate (mL/hr) for the Bolus Order?
•
𝑚𝑙
ℎ𝑟
=×
500𝑚𝑙
10𝑚𝑔
×
2𝑔
20𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
60000𝑚𝑙
200ℎ𝑟
• = Τ
300𝑚𝑙 ℎ𝑟
• What Is the IV Drip Rate (drops/min) for the Beginning Infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
10𝑔
×
2𝑔
20𝑚𝑖𝑛
• What Is the IV Rate (mL/hr) for the Continuous Infusion?
•
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
10𝑔
×
1𝑔
ℎ𝑟
• =
500𝑚𝑙
10ℎ𝑟
• = Τ
50𝑚𝑙 ℎ𝑟
• What Is the IV Drip Rate (drop/min) for the Continuous Infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
10𝑔
×
1𝑔
ℎ𝑟
×
1ℎ𝑟
60𝑚𝑖𝑛
DR MUSA 70
71. • EXAMPLE 3: The physician has ordered 1000 mL lactated Ringer’s with 10 g magnesium sulfate IV.
Bolus with 2 g/30 min, then maintain a continuous infusion at 2 g/h.
• What Is the IV Rate (mL/hr) for the Bolus Order?
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝑔
×
2𝑔
30𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
120000𝑚𝑙
300ℎ𝑟
• = Τ
400𝑚𝑙 ℎ𝑟
• What Is the IV Drip Rate (drop/min) for the Bolus Order?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
1000𝑚𝑙
10𝑔
×
2𝑔
30𝑚𝑖𝑛
• What Is the IV Rate (mL/hr) for the Continuous Infusion?
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝑔
×
2𝑔
ℎ𝑟
• =
2000𝑚𝑙
10ℎ𝑟
• = Τ
200𝑚𝑙 ℎ𝑟
• What Is the IV Drip Rate (drop/min) for the Continuous Infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑛𝑠
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
1000𝑚𝑙
10𝑔
×
2𝑔
ℎ𝑟
×
1ℎ𝑟
60𝑚𝑖𝑛
DR MUSA 71
72. IV ADMINISTRATION OF MEDICATIONS BY
MILLILITRES/ MINUTE OR MILLILITER/HOUR
• EXAMPLE 1: The physician has ordered 1000 mL lactated Ringer’s with 20 g magnesium sulfate IV.
Bolus with 400ml/hr, then maintain a continuous infusion at 200ml/hr.
• What Is the dosage (g/hr) for the Bolus Order?
•
𝑔
ℎ𝑟
=
20𝑔
1000𝑚𝑙
×
400𝑚𝑙
ℎ𝑟
• =
8000𝑔
1000ℎ𝑟
• = Τ
8𝑔 ℎ𝑟
• What Is the IV drip Rate (drops/min) for the Bolus Order?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
400𝑚𝑙
ℎ𝑟
×
1ℎ𝑟
60𝑚𝑖𝑛
• What Is the dosage (g/hr) for the Continuous Infusion?
•
𝑔
ℎ𝑟
=
20𝑔
1000𝑚𝑙
×
200𝑚𝑙
ℎ𝑟
• =
4000𝑔
1000ℎ𝑟
• = Τ
4𝑔 ℎ𝑟
• What Is the IV Drip Rate (drops/min) for the Continuous Infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
200𝑚𝑙
ℎ𝑟
×
1ℎ𝑟
60𝑚𝑖𝑛
DR MUSA 72
73. IV ADMINISTRATION OF MEDICATIONS BY DROPS/ MINUTE
• EXAMPLE 3: The physician has ordered 1000 mL D5W with 20 units IV oxytocin. Begin at 5 drops/min and then increase by 5
drops/min every 30 minutes until regular contractions occur. Maximum dose is 60 drops/min.
• What Is the IV Rate (ml/hr) for the Beginning Infusion?
•
𝑚𝑙
ℎ𝑟
=
𝑚𝑙
20𝑑𝑟𝑜𝑝𝑠
×
5𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
1ℎ𝑟
• =
300𝑚𝑙
20ℎ𝑟
• = Τ
15𝑚𝑙 ℎ𝑟
• What Is the dosage (mIU/min) for the Beginning Infusion?
•
𝑚𝐼𝑈
𝑚𝑖𝑛
=
1000𝑚𝐼𝑈
1𝐼𝑈
×
20𝐼𝑈
1000𝑚𝑙
×
1𝑚𝑙
20𝑑𝑟𝑜𝑝𝑠
×
5𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
• What Is the Maximum IV Rate(mL/hr) the Oxytocin Infusion May Be Set for?
•
𝑚𝑙
ℎ𝑟
=
𝑚𝑙
20𝑑𝑟𝑜𝑝𝑠
×
60𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
1ℎ𝑟
• =
3600𝑚𝑙
20ℎ𝑟
• = Τ
180𝑚𝑙 ℎ𝑟
• What Is the dosage (mIU/min) for the maximum Infusion set?
•
𝑚𝐼𝑈
𝑚𝑖𝑛
=
1000𝑚𝐼𝑈
1𝐼𝑈
×
20𝐼𝑈
1000𝑚𝑙
×
𝑚𝑙
20𝑑𝑟𝑜𝑝𝑠
×
60𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
• If the drip rate is 40drops/min what is the dosage (mIU/min) of oxytocin?
•
𝑚𝐼𝑈
𝑚𝑖𝑛
=
1000𝑚𝐼𝑈
1𝐼𝑈
×
20𝐼𝑈
1000𝑚𝑙
×
1𝑚𝑙
20𝑑𝑟𝑜𝑝𝑠
×
40𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
• =
800000𝑚𝐼𝑈
20000𝑚𝑖𝑛
• = Τ
40𝑚𝐼𝑈 𝑚𝑖𝑛
• If the drip rate is 40drops/min what is the IV Rate (mL/hr) the Oxytocin set for?
•
𝑚𝑙
ℎ𝑟
=
𝑚𝑙
20𝑑𝑟𝑜𝑝𝑠
×
40𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
DR MUSA 73
74. INFERTILITY
• How many pregnancies can be achieve by one
normal ejaculate?
•
𝑝𝑟𝑒𝑔𝑛𝑎𝑛𝑐𝑖𝑒𝑠
𝑒𝑗𝑎𝑐𝑢𝑙𝑎𝑡𝑒
=
1𝑝𝑟𝑒𝑔𝑛𝑎𝑛𝑐𝑦
1𝑒𝑚𝑏𝑟𝑦𝑜
×
1𝑒𝑚𝑏𝑟𝑦𝑜
1𝑠𝑝𝑒𝑟𝑚
×
15000000𝑠𝑝𝑒𝑟𝑚𝑠
𝑒𝑗𝑎𝑐𝑢𝑙𝑎𝑡𝑒
•
𝑝𝑟𝑒𝑔𝑛𝑎𝑛𝑐𝑖𝑒𝑠
𝑒𝑗𝑎𝑐𝑢𝑙𝑎𝑡𝑒
=
15000000𝑝𝑟𝑒𝑔𝑛𝑎𝑛𝑐𝑖𝑒𝑠
𝑒𝑗𝑎𝑐𝑢𝑙𝑎𝑡𝑒
DR MUSA 74
75. EXERCISE 1
The physician has ordered 500mL D5W with 5units oxytocin intravenously.
Begin at 5mIU/min and then increase by 5mIU every 30minutes until active
labor is achieved. Maximum dose is 30mIU/min.
a. Calculate the IV rate (ml/hr) for the beginning infusion
b.
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
5𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
5𝑚𝐼𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
c. Calculate the IV drip rate (drops/min) for the beginning infusion.
d.
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
5𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
5𝑚𝐼𝑈
𝑚𝑖𝑛
e. What is the maximum IV rate (ml/hr) the Pitocin infusion may be set for?
f.
𝑚𝑙
ℎ𝑟
=
500𝑚𝑙
5𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
5𝑚𝐼𝑈
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
g. What is the maximum IV drip rate (drops/min) the Pitocin infusion may
be set for?
h.
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
5𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
DR MUSA 75
76. EXERCISE 2
The physician has ordered 500mL D5W with 10units oxytocin intravenously.
Begin at 5drops/min and then increase by 5drops every 30minutes until
active labor is achieved. Maximum dose is 40drops/min.
a. Calculate the IV rate (ml/hr) for the beginning infusion
b.
𝑚𝑙
ℎ𝑟
=
𝑚𝑙
20𝑑𝑟𝑜𝑝𝑠
×
5𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
c. Calculate the IV dosage (mIU/min) for the beginning infusion.
d.
𝑚𝐼𝑈
𝑚𝑖𝑛
=
1000𝑚𝐼𝑈
1𝐼𝑈
×
10𝐼𝑈
500𝑚𝑙
×
𝑚𝑙
20𝑑𝑟𝑜𝑝
×
5𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
e. What is the maximum IV rate (ml/hr) the Pitocin infusion may be set for?
f.
𝑚𝑙
ℎ𝑟
=
𝑚𝑙
20𝑑𝑟𝑜𝑝𝑠
×
40𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
g. What is the maximum dosage (mIU/min) of the Pitocin infusion may be
set for?
h.
𝑚𝐼𝑈
𝑚𝑖𝑛
=
1000𝑚𝐼𝑈
1𝐼𝑈
×
10𝐼𝑈
500𝑚𝑙
×
𝑚𝑙
20𝑑𝑟𝑜𝑝𝑠
×
40𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
DR MUSA 76
77. EXERCISE 3
The physician has ordered 500mL D5W with 10units oxytocin intravenously.
Begin at 0.5ml/min and then increase by 0.5ml every 30minutes until active
labor is achieved. Maximum dose rate is 3ml/min.
a. Calculate the IV dose (mIU/min) for the beginning infusion
b.
𝑚𝐼𝑈
𝑚𝑖𝑛
=
1000𝑚𝐼𝑈
1𝐼𝑈
×
10𝐼𝑈
500𝑚𝑙
×
0.5𝑚𝑙
𝑚𝑖𝑛
c. Calculate the IV drip rate (drops/min) for the beginning infusion.
d.
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
0.5𝑚𝑙
𝑚𝑖𝑛
e. What is the maximum IV dosage (mIU/min) of the Pitocin infusion may
be set for?
f.
𝑚𝐼𝑈
𝑚𝑖𝑛
=
1000𝑚𝐼𝑈
1𝐼𝑈
×
10𝐼𝑈
500𝑚𝑙
×
3𝑚𝑙
𝑚𝑖𝑛
g. What is the maximum IV drip rate (drops/min) the Pitocin infusion may
be set for?
h.
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
3𝑚𝑙
𝑚𝑖𝑛
DR MUSA 77
78. EXERCISE 4
• EXAMPLE 1: The physician has ordered 1000 mL lactated Ringer’s with 20 g magnesium sulfate IV.
Bolus with 4 g/30 min, then maintain a continuous infusion at 2 g/h. The magnesium is available as
50% solution.
• How much of concentrated magnesium solution added to the lactated ringers (ml)?
•
𝑚𝑙
=
100𝑚𝑙
50𝑔
×
20𝑔
• How many ml of the concentrated magnesium solution was given as bolus?
•
𝑚𝑙
=
100𝑚𝑙
50𝑔
×
4𝑔
• What Is the IV Rate (mL/h) for the Bolus Order?
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
20𝑔
×
4𝑔
30𝑚𝑖𝑛
×
60𝑚𝑖𝑛
ℎ𝑟
• =
240000𝑚𝑙
600ℎ𝑟
• = Τ
400𝑚𝑙 ℎ𝑟
• How much of concentrated magnesium solution in ml/hr is given as continuous infusion?
•
𝑚𝑙
ℎ𝑟
=
100𝑚𝑙
50𝑔
×
2𝑔
ℎ𝑟
• What Is the IV Rate (mL/h) for the Continuous Infusion?
•
𝑚𝑙
ℎ𝑟
=
1000𝑚𝑙
10𝑔
×
2𝑔
ℎ𝑟
• =
2000𝑚𝑙
10ℎ𝑟
• = Τ
200𝑚𝑙 ℎ𝑟
DR MUSA 78
79. EXERCISE
• A HIV + patient is admitted to the hospital for C-section delivery. The orders from the physician include:
➢ Admit to OB in private room
➢ NPO
➢ Up ad lib
➢ CBC and electrolytes
➢ Type and cross-match for 2 units of blood
➢ Admission weight 164 lb
➢ Lactated Ringers IV at 100 mL/hr
➢ Zidovudine 2 mg/kg IV over 1 hour on admission to labor and delivery then zidovudine 1mg/kg/hr continuous IV infusion
beginning 3 hours prior to C-section
➢ Cefazolin 1 g IVPB × 1 dose 1 hour prior to C-section
➢ Metoclopramide (Reglan) 10 mg IV push every 6 hours prn for nausea and vomiting
➢ Hydrocodone 5 mg and acetaminophen 325 mg PO two tablets every 4 hours prn for moderate to severe pain
➢ Docusate sodium 100 mg PO two capsules bid
• Identify the orders that require calculations.
• Set up and solve each problem using dimensional analysis.
1. Calculate the weight of the patient in kilograms.
2. Calculate how many mL/hr to set the IV pump to infuse zidovudine 2 mg/kg over 1 hour. Supply: Zidovudine
200 mg/50 mL D5W.
3. Calculate mL/hr to set the IV pump to infuse zidovudine 1 mg/kg/hr. Supply: Zidovudine 400 mg/100 mL
D5W.
4. Calculate mL/hr to set the IV pump to infuse cefazolin 1 g IV. Supply: Cefazolin (Ancef) 1000 mg/100 mL D5W
to be administered over 30 minutes.
5. Calculate how many mL of metoclopramide 10 mg will be given IV push over 2 minutes. Supply: Reglan 5
mg/mL
DR MUSA 79
80. • EXAMPLE 3: The physician has ordered 500 mL NS with 20 units IV oxytocin at 30mIU/min to
prevent postpartum haemorrhage.
• What Is the IV Drip Rate (drops/min) for the Infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
20𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
30𝑚𝐼𝑈
𝑚𝑖𝑛
• =
300000𝑑𝑟𝑜𝑝𝑠
20000𝑚𝑖𝑛
• = Τ
15𝑑𝑟𝑜𝑝𝑠 𝑚𝑖𝑛
• If 10IU was added to 500ml at 40mIU/min. what is the IV drip rate (drops/min) for the infusion?
•
𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
=
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑙
×
500𝑚𝑙
20𝐼𝑈
×
1𝐼𝑈
1000𝑚𝐼𝑈
×
40𝑚𝐼𝑈
𝑚𝑖𝑛
• =
400000𝑑𝑟𝑜𝑝𝑠
20000𝑚𝑖𝑛
• =
20𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
• If the drip rate is 40drops/min what is the dosage (mIU/min) of oxytocin?
•
𝑚𝐼𝑈
𝑚𝑖𝑛
=
1000𝑚𝐼𝑈
1𝐼𝑈
×
20𝐼𝑈
500𝑚𝑙
×
𝑚𝑙
20𝑑𝑟𝑜𝑝𝑠
×
40𝑑𝑟𝑜𝑝𝑠
𝑚𝑖𝑛
• =
800000𝑚𝐼𝑈
10000𝑚𝑖𝑛
• = Τ
80𝑚𝐼𝑈 𝑚𝑖𝑛
DR MUSA 80
81. CALCULATION CHOICE
• The CASE approach should be implemented to prevent calculation
errors. Any of the three methods (ratio-proportion, formula, or
dimensional analysis) may be used to solve basic calculations.
However, when multiple conversions are necessary, as in complex
IV rate calculations, ratio-proportion is generally not use. Several
different formulas are needed to perform all types of dosage
calculation by formula method. Many find it difficult to memorize
and recall the various formula which may result in dosage
calculation errors.
• Dimensional analysis can be used when no conversion is needed
but it is particularly useful when multiple conversions are needed to
calculate the dose. All dosage calculations can be performed using
dimensional analysis. Because dimensional analysis is less-prone, it
is the preferred calculation method of many institutions.
DR MUSA 81
82. CASE
• C: covert- convert to like units of measurement. Example
order dose may be gram g while the supply is in milligrams
(mg). Requires comparing the supply to the ordered dose and
converting to the same unit of measurement, if they are
different
• A: approximate: requires approximating how much of the
supplied medication to administer. Requires the comparism of
the dosage strength (referred to as ‘supply’) to the ordered
dose. For example ordered dose may be in grams (g), while
the supply is in milligrams (mg)
• S: solve-perform dosage calculation
• E: Evaluate- check the dosage calculation and compare to
approximate amount
The word CASE also reminds the nurse to consider the
appropriateness of the medication and dose ordered in each
individual case DR MUSA 82
