Obgyn med maths problems and solutions using dimensional analysis (2)

DIMENSIONAL ANALYSIS
OBGYN
Dr MUSA MARENA
OBGYN Med Maths problems and solutions using dimensional analysis
1. The order is infuse Dopamine 400mg in 250ml of D5W at 30microdrops/min . Calculate the
mg/min and mg/hr that the patient will receive.
• Measure is mg/min
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 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
2. A doctor orders pitocin drip at 45microdrips per minute. The solution contains 20U of Pitocin
in 1000ml of D5W. Calculate the units per minute and the unit per hour the patient is
receiving.
Unit of measure is unit per minute ie U/min
Note microdrips means the set calibration is 60drops/ml
U/hr = 20U/1000ml × ml/60drops × 45drops/min
= 900U/60000min
= 0.015U/min
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
3. The physician has ordered 500ml D5W with 10units IV oxytocin. Begin at 2mU/min and then
increase by 1mU/min every 30min until regular contractions begin. Maximum dose is
30mU/min.
a. What is the IV flow rate for the beginning infusion?
b. What is the IV flow rate for the maximum infusion?
• Measure is flow rate

OBGYN
Dr MUSA MARENA
Unit of measure ml/hr
ml/hr = 500ml/10U × 1U/1000mU × 2mU/min × 60min/hr
= 600000ml/10000hr
= 6ml/hr
= 180000ml/10000hr
= 18ml/hr
4. There is an outbreak of scarcoptic mange at your rabbit farm and your veterinarian
prescribed subcutaneously 400mcg/kg Ivermectin once every fortnight for three
consecutive doses. Ivermectin dosage is 200-400mcg/kg
You have 50 units of rabbits on your farm and average weight of each rabbit is 3kg.
The Ivermectin comes in 1% w/v in 50ml bottle. Each bottle cost €27.84?
How many bottles per dose do you need?
How many bottles of 50ml Ivermectin will be needed to completely treat your
rabbits?
What is the total cost of the treatment?
How many milliliters per unit per dose do you need? how many milliliters of
Ivermectin will you need to treat you whole farm?
How many milligrams per dose do you need on your farm? How many milligrams of
the drug is required to treat the whole farm?
How much money will be spent on the cost of treatment of each dose? How much will
it cost to treat a unit of rabbit?
• Measure is quantity
Unit of measure bottle/dose
Unit of rabbit consist of 10 rabbits
1% w/v Ivermectin means 1g of Ivermectine in b 100ml of solution
bottle/dose = 1bottle/50ml × 100ml/1g × 1g/1000mg × 1mg/1000mcg
× 400mcg/kg × 3kg/1rabbit × 10rabbit/unit × 50unit/dose
= 600000000bottle/50000000dose
= 1.2bottle/dose
You cannot buy 1.2bottle hence
= 2bottle/dose
• Measure is amount
Unit of measure bottles
Bottles = bottle/50ml × 100ml/1g × 1g/1000mg × 1mg/1000mcg ×
400mcg/kg × 3kg/1rabbit × 10rabbit/1unit × 50units/dose ×
1dose/week × 3weeks/1

OBGYN
Dr MUSA MARENA
= 1800000000bottles/50000000
= 3.6bottles
You cannot buy 3.6bottles hence
= 4bottles
Unit of measure euro
€ = €27.84/bottle × 1bottle/50ml × 100ml/1g × 1g/1000mg ×
1mg/1000mcg × 400mcg/1kg × 3kg/rabbit × 10rabbit/1unit ×
50units/dose × 1dose/1week × 3weeks/1
= €5011200000/50000000
= €100.22
• In reality € = €27.84/bottle × 4bottle/1
= €111.36
• Measure is volume
Unit of measure milliliters/unit/dose
ml/unit/dose = 100ml/1g × 1g/1000mg × 1mg/1000mcg × 400mcg/kg
× 3kg/rabbit × 10rabbit/unit/dose
= 1200000ml/1000000unit/dose
= 1.2ml/unit/dose
Unit of measure milliliters
ml = 100ml/1g × 1g/1000mg × 1mg/1000mcg × 400mcg/1kg ×
3kg/1rabbit × 10rabbit/1unit × 50units/dose × 1dose/week × 3weeks/1
= 1800000000ml/100000000
= 180ml
• Measure is amount/dose
Unit of measure mg/dose
mg/dose = 1mg/1000mcg × 400mcg /kg × 3kg/rabbit × 10rabbit/unit ×
50units/dose
= 600000mg/ 1000dose
= 600mg/dose
Unit of measure milligram
mg = 1mg/1000mcg × 400mcg/1kg × 3kg/1rabbit × 10rabbit/1unit ×
50units/dose × 1dose/1week × 3weeks/1
= 1800000mg/1000
= 1800mg
Unit of measure euro/dose
€/dose = €27.84/bottle × 1bottle /50ml × 100ml/1g × 1g/1000mg ×
1mg/1000mcg × 400mcg/kg × 3kg/1rabbit × 10rabbit/unit ×
50units/dose
= €1870400000/50000000dose

OBGYN
Dr MUSA MARENA
= €33.41
• In reality € = €27.84/1bottle × 2bottle/1
= €55.68
Unit of measure euro/unit
€/unit = €27.84/1bottle × 1bottle/50ml × 100ml/1g × 1g/1000mg ×
1mg/1000mcg × 400mcg/kg × 3kg/rabbit × 10rabbits/unit
= 33408000/50000000dose
= €0.67
5. Your kitten is very sick and your vet prescribed medicine. You need to give your kitten
550mg of medicine every 8 hours for the next 3 weeks. The medicine is only sold in 225mg
tablets. A bottle of 18tablets cost $10.95 (including tax). How many bottles of medicine
should you buy to save your kitten from the grip of death and how much will it cost you?
• Measures is amount
Unit of measure bottle
bottle = 1bottle/18tablet × 1tablet/225mg × 550mg/8hrs × 24hrs/day ×
7day/week × 3week/1
= 277200bottle/32400
= 8.6bottles
You cannot buy 8.6bottles hence
= 9 bottles
• Measure is dollars
Unit of measure is $
$ = $10.95/1bottle × 1bottle/18tablet × 1tablet/225mg × 550mg/8hrs ×
24hrs/day × 7day/week × 3week/1
= $3035340/32400
= $93.68
In reality $ = $10.95/1bottle × 9bottle
= $98.55/1
= $98.55
6. The obstetrician has ordered Pitocin infusion for Augmentation of Labour in 20YO
primigravida. Begin at 15drops/min and increase by 5mU/min every 30mins until regular
contractions begin. Maximum dose is 60drops/min. Pitocin- 1ml vials with 10unit/vial. The
L&D protocol is mix 1 vial per 500ml NS
a. What is the dose in mU/min for the beginning infusion?
b. What is the drip rate of the regular increase using microdrip set?
c. What is the dose in mU/min for the maximum infusion?
Unit of measure mU/min
mU/min = 1000mU/1U × 5U/500ml × 1ml/60drops × 15drops/min

OBGYN
Dr MUSA MARENA
= 75000mU/30000min
= 2.5mU/min
• Measure is drip rate
Unit of measure drops/min
drops/min = 60drops/ml × 500ml/5U × 1U/1000mU × 5mU/min
= 150000drops/5000min
= 30drops/min
• Measure is dose
Microdrip gives 60drops for every 1ml
= 300000mU/30000min
= 10mU/min
7. A 28YO female (50kg) is admitted with post maturity in hospital. It is decided to induce
Labour. All the contraindications are ruled out. Set an IV infusion drip rate of oxytocin for her
using microdrip set. (Rate of infusion- 4milli unit/min). L&D pre-mixed bag contains 5unit of
Pitocin in 500ml NS
Microdrip gives 60drops for every 1ml
= 120000drops/5000min
= 24drops/min
8. Tridil is infusing at 15 mL/hr on an infusion pump. The drug is mixed 50 mg in 500 mL D5W.
How many mcg/minute is the patient receiving?

OBGYN
Dr MUSA MARENA
Unit of measure mcg/min
mcg/min = 1000mcg/1mg × 50mg/500ml × 15ml/hr × 1hr/60min
= 750000mcg/30000min
= 25mcg/min
9. The patient's heparin is infusing at 28 mL/hr on an infusion pump. The bag of fluid is mixed
20,000 units of heparin in 500 mL D5W. What hourly dose of heparin is the patient
receiving?
Unit of measure unit/hr
unit/hr = 20000unit/500ml × 28ml/hr
= 560000unit/500hr
= 1120unit/hr
10. Ordered - 2mU/min
Pitocin - 1ml vials with 10unit/ml
Protocol on L&D - mix 2 vials per 1000ml NS
What does the IV pump need to be set at?
ml/hr = 1000ml/2vials × 1vial/10unit × 1unit/1000mU × 2mU/min ×
60min/hr
= 120000ml/20000hr
= 6ml/hr
11. One liter NS to infuse over 24 hours using a microdrip (gravity flow). Calculate the flow rate.
Microdrip gives 60drops sb for every 1ml
drops/min = 60drops/ml × 1000ml/1L × 1L/24hrs × 1hr/60min
= 60000drops/1440min
= 41.67drops/min
= 42drops/min

OBGYN
Dr MUSA MARENA
12. Order: Zofran 8 mg p.o.t.i.d.
Available: Zofran in a 100 mL bottle labeled 4 mg/tsp. How many mL will the nurse
administer for each dose?
Unit of measure ml/dose
1teaspoon full gives 5ml
ml/dose = 5ml/1tsp × 1tsp/4mg × 8mg/dose
= 160ml/dose
13. Give Ceclor 45 mg/kg/day p.o. in 3 divided doses for a patient who weighs 66 pounds. A 75
mL stock medication is labeled Ceclor 125 mg/mL. How many mL would the nurse
administer per dose?
ml/dose = ml/125mg × 45mg/kg/day × 1kg/2.2Ib × 66Ib/1 × 1day/3doses
= 2970ml/825doses
= 3.6ml/dose
14. Administer Heparin 1,000 units/hr from an l.V. bag mixed 40,000 units in 1 L D5W. How
many mL/hr will deliver the correct amount of heparin?
ml/hr = 1000ml/1L × 1L/40000unit × 1000unit/hr
= 1000000ml/40000hr
= 25ml/hr
15. Give Tridil 15 mcg/minute. Tridil is mixed 50 mg in 500 mL D5W. What rate on the infusion
pump will deliver the correct dose?
ml/hr = 500ml/50mg × 1mg/100mcg × 15mcg/min × 60min/1hr

OBGYN
Dr MUSA MARENA
= 450000ml/50000hr
= 9ml/hr
16. A lidocaine drip is infusing at 30 mL/hr on an infusion device. The drug is mixed 2 g in 500 mL
D5W. How many mg/min is the patient receiving?
• Measure is dosages
mg/min = 1000mg/1g × 2g/500ml × 30ml/hr × 1hr/60min
= 60000mg/30000min
= 2mg/min
17. Give propofol 10 mcg/kg/minute. The infusion is mixed propofol 250 mg in 250 mL D5W. The
patient weighs 168 pounds. What rate on the infusion pump will deliver the correct dose?
ml/hr = 250ml/250mg × 1mg/1000mcg × 10mcg/kg/min × 1kg/2.2Ib × 168Ib
× 60min/hr
= 25200000ml/550000hr
= 45.8ml/hr
18. Give regular insulin by continuous I.V. Infusion at 20unit/hr. The solution is 250ml in NS with
100units of Regular insulin. What rate on the infusion pump will deliver the correct dose?
ml/hr = 250ml/100unit × 20unit/hr
= 5000ml/100hr
= 50ml/hr
19. At the change of shift, you notice that 200ml left to count in I.V. bag. The I.V. Is infusing at
80mL/hr. How much longer will the I.V. run? (Express your answer in hours and minutes.)
• Measure is time
Unit of measure hours and minutes
hr = 1hr/80ml × 200ml/1

OBGYN
Dr MUSA MARENA
= 200hr/80
= 2.5hr
Unit of measure minutes
min = 60min/1hr × 0.5hr/1
= 30mins/1
= 30mins
• Duration of time of infusion will be 2hrs 30mins
20. Give Biaxin for a child whose BSA is 0.55 m2
. The usual adult dose is 500 mg. Biaxin is
available in an oral suspension. The 100 Ml bottle is labeled 50 mg/mL. How many mL would
the nurse give per dose?
Unit of measure ml
Adult body surface area 1.73m2
ml = ml/50mg × 500mg/1.73m2
× 0.55m2
/1
= 275ml/86.5
= 3.18ml
= 3.2ml
21. Give Phenergan for a child whose BSA is 1.2 m2
. The usual adult dose is 25 mg. How many
milligrams would the nurse administer for the dose?
Unit of measure is mg/dose
The average body surface area of an adult is 1.73meters square
mg/dose = 25mg/1.73m2
/dose × 1.2m2
/1
= 30mg/1.73dose
= 17.3mg/dose
22. Keflin 2g in 100ml D5W IVPB over 20minutes. The I.V tubing is 15gtt/ml. Calculate the flow
rate in drops/min?

OBGYN
Dr MUSA MARENA
drops/min = 15drops/ml × 100ml/20min
= 1500drops/20min
= 75drops/min
23. The patient's heparin drip is infusing at 11 mL/hr on an infusion pump. The bag of fluid is
mixed 25,000 units of heparin in 250 mL D5W. What hourly dose of heparin is the patient
receiving?
Unit of measure unit/hr
unit/hr = 25000unit/250ml × 11ml/hr
= 275000unit/250hr
= 1100unit/hr
24. Administer a Theophylline drip at 40 mg/hr 1.V. The solution is 250 mL D5W + Theophylline
500 mg. What rate on the infusion pump will deliver the correct dose?
ml/hr = 250ml/500mg × 40mg/hr
= 10000ml/500hr
= 20ml/hr
25. Aminophylline is infusing at 30 mL/hr. The drug is mixed 250 mg in 500 mL D5W. How many
mg/hr is the patient receiving?
mg/hr = 250mg/500ml × 30ml/hr
= 7500mg/500hr
= 15mg/hr
26. Give Nitroprusside 5 mcg/kg/minute via continuous infusion for a patient weighing 205 lbs.
Nitroprusside is available in a solution of 200 mg in 250 mL D5W. What rate on the infusion
pump will deliver the correct dose?

OBGYN
Dr MUSA MARENA
• Measures is flow rate
Unit of measure
ml/hr = 250ml/200mg × 1mg/1000mcg × 5mcg/kg/min × 1kg/2.2Ib × 205Ib ×
60min/hr
= 15375000ml/440000hr
= 34.9ml/hr
27. A physician ordered 800mg/kg of medication to be taken in equally divided doses four times
per day for a pediatric patient who weighs 67.5Ib. The medication is available in 3g per
capsule. How many capsules should the patient take per dose? Round to the nearest whole.
• Measure is amount per dose
Unit of measure capsule/dose
capsule/dose = capsule/3g × 1g/1000mg × 800mg/kg/day × 1kg/2.2Ib ×
67.5Ib 1day/4doses
= 54000capsule/26400doses
= 2capsule/dose
28. The provider prescribes amoxicillin (Amoxil) 20mg/kg/day PO to be given in 2 divided doses.
The client weighs 44 lb. The amount available is amoxicillin 250mg/5mL. How many mL
should the nurse administer per dose?
ml/dose = 5ml/250mg × 20mg/kg/day × 1kg/2.2Ib × 44Ib/1 × 1day/2doses
= 4400ml/1100dose
= 4ml/dose
29. The provider prescribes cefixime (Suprax) 8 mg/kg/day PO to be given in 2 divided doses.
The client weighs 22 lb. The amount available is 100 mg/5 mL suspension. How many mL
should the nurse administer per dose?
• Measure is amount per dose
ml/dose = 5ml/100mg × 8mg/kg/day × 1kg/2.2Ib × 22Ib/1 × 1day/2doses
= 880ml/44dose
= 2ml/dose

OBGYN
Dr MUSA MARENA
30. The prescriber writes an order for 1,000mL of 5% D/W with 10units of a drug. Your patient
must receive 30mU of this drug per minute. Calculate the drip rate in drops per minute using
microdrip set
Microdrop means 60drops gives 1ml
= 1800000drops/10000min
= 180drops/min
31. The medication order reads: 1,000mL 5% D/W with 1,000mg of a drug at 1mg/min Calculate
the drip rate in drops per minute if the drop factor is 15drops/milliliter
drops/min = 15drops/ml × 1000ml/1000mg × 1mg/min
= 15drops/min
32. The patient is to receive 20 mEq of KCl (potassium chloride) in 100 mL of IV fluid at the rate
of 10mEq/h. What is the flow rate in microdrips per minute?
Microdrip means infusion set gives 60drops for every ml
drops/min = 60drops/ml × 100ml/20mEq × 10mEq/hr × 1hr/60min
= 50drops/min
33. A patient is receiving heparin 1,200units/hour. The directions for the infusion are, add
“25,000 units of heparin in 250 mL of solution.” Determine the flow rate in mL/h.
ml/hr = 250ml/25000U × 1200U/hr

OBGYN
Dr MUSA MARENA
= 300000ml/25000hr
= 12ml/hr
34. Doctor orders that a patient in labour with inadequate contractions should be augmented
with Pitocin 5miu/min and increasing the dose by 5miu every 30mins until contractions are
3-5 in 10mins lasting 40-60 seconds and maintain the dose attain to achieve 3-5contractions
in 10mins upto maximum dose of 30mU/min. What will be the flow rate? What will be the
drips rate and the increase drip rate at each 30mins? The L&D protocol is 5unit of Pitocin in
500ml of NS and giving set gives 1ml for every 15drops
• Measures is Flow rate
= 150000ml/5000hr
= 30ml/hr
= 7.5drops/min
= 8drops/min
• Measure is increase drip rate
Unit of measure drop/min
drops/min = 15drops/ml × 500ml/5U × 1U/1000mU × 5mU/30min
= 37500drops/150000min
= 0.25drops/min
35. Order: Tagamet (cimetidine) 300mg IVPB q6h in 50mL NS infuse over 30min. The drop factor
is 20gtt/ml. Find the flow rate in gtt/min.
Unit of measure gtt/min ie drops/min
gtts/min = 20gtt/ml × 50ml/30min
= 1000gtt/30min
= 33.3gtt/min

OBGYN
Dr MUSA MARENA
= 33gtt/min
36. The order is for a continuous infusion of theophylline at a rate of 25mg/h. It is diluted in 5%
dextrose to produce a concentration of 500mg per 500mL. Determine the rate of the
infusion in mL/h.
= 12500ml/500hr
= 25ml/hr
37. A 500mL D5W solution with 2g of Pronestyl (procainamide HCl) is infusing at 15mL/h via a
volumetric pump. How many mg/h is the patient receiving?
mg/hr = 1000mg/1g × 2g/500ml × 15ml/hr
= 30000mg/500hr
= 60mg/hr
38. The physician has ordered 500mL D5W with 5units oxytocin intravenously. Begin at
5mU/min and then increase by 5mU/min every 30minutes until active labor is achieved.
Maximum dose is 30mU/min. drop factor 60drops = 1min
• Calculate the IV rate (ml/hr) for the beginning infusion
• Calculate the IV drip rate (drops/min) for the beginning infusion.
• What is the maximum IV flow rate the Pitocin infusion may be set for?
• What is the maximum IV drip rate (drops/min) the Pitocin infusion may be set for?
= 150000ml/5000hr
= 30ml/hr

OBGYN
Dr MUSA MARENA
= 150000drops/5000min
= 30drops/min
= 900000ml/5000hr
= 1800ml/hr
= 900000drops/5000min
= 180drops/min
39. The physician has ordered 500mL D5W with 2.5units oxytocin intravenously. Begin at
2mU/min and then increase by 2mU/min every 30 minutes until regular contractions occur.
The maximum dose is 20mU/min. The giving sets is 1ml gives 20drops
a. Calculate the IV rate (mL/hr.) for the beginning infusion.
b. Calculate the IV drip rate (drops/min) for the beginning infusion.
c. Calculate the maximum IV flow rate the Pitocin infusion may be set for.
d. Calculate the maximum IV drip rate (drop/min) the Pitocin infusion may be set for.
ml/hr = 500ml/2.5U × 1U/1000mU × 2mU/min × 60min/hr
= 60000ml/2500hr
= 24ml/hr
Unit of measure is drops/min

OBGYN
Dr MUSA MARENA
drops/min = 20drops/ml × 500ml/2.5U × 1U/1000mU × 2mU/min
= 8drops/min
ml/hr = 500ml/2.5U × 1U/1000mU × 20mU/min × 60min/hr
= 600000ml/2500hr
= 240ml/hr
drops/min = 20drops/ml × 500ml/2.5U × 1U/1000mU × 20mU/min
= 200000drops/2500min
= 80drops/min
40. Order: Intropin (dopamine) 2mcg/kg/min IVPB, titrate to maintain SBP above 90, increase by
5mcg/kg/min q 10–30minutes. Maximum dose 20mcg/kg/min. Monitor BP and HR q 2–
5minutes during titration. The label on the 500mL medication bag states 800mcg/ml, and
the patient Weighs 175pounds.
a. How many mcg/min of Intropin should the patient receive initially?
b. Calculate the initial pump setting in mL/h.
mcg/min = 2mcg/kg/min × 1kg/2.2Ib × 175lb
= 350mcg/2.2min
= 159.1mcg/min
Unit of measure is ml/hr
ml/hr = 1ml/800mcg × 2mcg/kg/min × 1kg/2.2lb × 175lb × 60min/1hr
= 21000ml/1760hr
= 11.93ml/hr

OBGYN
Dr MUSA MARENA
41. The doctor orders the post-operative patient should receive 150g of glucose as 30% sorbitol
in 24hrs as the daily energy requirement. The drip rate 30drops/min what is the volume of
sorbitol given to the patient? What is the drop factor of the IV set? What is the dose of
sorbitol given to the patient?
Unit of measure ml
Sorbitol is higher concentration of glucose; 30% of sorbitol means 30g of
glucose in 100ml of sorbitol solution
ml = 100ml/30g × 150g
= 15000ml/30
= 500ml
• Measure is drop factor
Unit of measure drops/ml
drops/ml = 30drops/min × 60min/1hr × 24hrs/150g × 30g/100ml
= 1296000drops/15000ml
= 86.4drops/ml
= 86drops/ml
mg/min = 1000mg/1g × 150g/24hrs × 1hr/60min
= 150000mg/1440min
= 104.17mg/min
= 104mg/min
42. Gynaecologist performing hysteroscopic metroplasty uses iso osmolar distending medium
containing mannitol 5% and glycine 2.2%. If the flow rate is 90ml/min, what is the dose of
mannitol? How many grams of glycine had been infused after 1hr of the operation?
a. If the doctor increases the dose of mannitol to 8g/min. What is the flow rate of
mannitol? What is the dose of glycine infusing?
b. If the flow rate was adjusted such that the drip rate is 800drops/min, what will be the
flow rate if the drop factor of the IV set is 15drops/ml. what will be the dose of
mannitol? How many grams of glycine had been infused after 2hrs?
c. If the given set was change and drip rate was adjusted to 600drops/min and the dose of
glycine is 11g/min. what is the drop factor of the of the new IV set? What is the flow rate
of glycine? How long will it take to infuse 40g of glycine? How much volume of the fluid
will be infused in order to give 80g of mannitol? How many grams of mannitol are there

OBGYN
Dr MUSA MARENA
be in 800ml of the iso osmolar solution? How many grams of glycine are there in 300ml
of the solution?
5% of mannitol solution means there are 5g of mannitol for every 100ml of
mannitol solution
mg/min = 1000mg/1g × 5g/100ml × 90ml/min
= 450000mg/100min
= 4500mg/min
• Measure is weight
Unit of measure grams
2.2% of glycine solution means 2.2g of glycine for every 100ml of glycine
solution
g = 2.2g/100ml × 90ml/min × 60min/1hr × 1hr/1
= 11880g/100
= 118.8g
ml/hr = 100ml/5g × 8g/min × 60min/hr
= 6000ml/5hr
= 1200ml/hr
Unit of measure g/min
g/min = 2.2g/100ml × 1200ml/hr × 1hr/60min
= 2640g/6000min
= 0.44g/min
ml/hr = ml/15drops × 800drops/min × 60min/1hr
= 48000ml/15hr
= 3200ml/hr

OBGYN
Dr MUSA MARENA
mg/min = 1000mg/1g × 5g/100ml × 1ml/15drops × 800drops/min
= 4000000mg/1500min
= 2666.67mg/min
= 2666.7mg/min
g = 2.2g/100ml × 1ml/15drops × 800drops/min × 60min/1hr × 2hr/1
= 211200g/1500
= 140.8g
drops/ml = 600drops/min × min/11g × 2.2g/100ml
= 1320drops/1100ml
= 1.2drops/ml
= 1drop/ml
ml/hr = 100ml/2.2g × 11g/min × 60min/hr
= 66000ml/2.2hr
= 30000ml/hr
• Measure is time
hr = 1hr/60min × min/11g × 40g
= 40hr/660
= 0.06hr
Unit of measure ml
ml = 100ml/5g × 80g
= 8000ml/5
= 1600ml

OBGYN
Dr MUSA MARENA
g = 5g/100ml × 800ml
= 4000g/100
= 40g
g = 2.2g/100ml × 300ml
= 660g/100
= 6.6ggrams of glycine are there in 300ml of the solution?
43. Gynaecologist performing hysteroscopy uses 1.5% Glycine as distending medium. If the flow
rate is 80ml/min, how many grams of glycine will the infusion into the uterus if the
operation lasted for 3hrs? If the flow rate is change to 100ml/min what is the dose in
mg/min of glycine infusion? If the drop factor of the IV set is 10drops/ml what is the new
drip rate? The assistant changes the giving set to give 10drops/sec in order to be able to give
150mg/min. what is the new flow rate in ml/min. what is the drop factor of the new IV set?
1.5% glycine solution means 1.5g of glycine in 100ml of solution.
g = 1.5g/100ml × 80ml/min × 60min/hr × 3hr/1
= 21600g/100
= 216g
mg/min = 1000mg/1g × 1.5g/100ml × 100ml/min
= 150000mg/100min
= 1500mg/min
drops/min = 10drop/ml × 100ml/min
= 1000drops/min

OBGYN
Dr MUSA MARENA
ml/hr = 100ml/1.5g × 1g/1000mg × 150mg/min × 60min/hr
= 900000ml/1500hr
= 600ml/hr
Unit of measure drop/ml
drops/ml = 10drops/sec × 60sec/min × min/150mg × 1000mg/1g ×
1.5g/100ml
= 900000drops/15000ml
= 60drops/ml
44. The nurse notes the patient’s IV pump is set at 10ml/hr. The IV bag holds 30 units of Pitocin
mixed in 500ml of Lactated Ringers. How many mu/min is the client receiving? What is the
drip rate using the standard mircodrip? How long will it to transfuse the whole Pitocin bag?
• Measure is dose
mU/min = 1000mU/1U × 30U/500ml × 10ml/hr × 1hr/60mins
= 300000mU/30000min
= 10mU/min
Microdrip is 1ml = 60drops
drops/min = 60drops/ml × 10ml/hr × 1hr/60min
= 600drops/60min
= 10drops/min
• Measure is time
Unit of measure hours/bag
hr/bag = 1hr/10ml × 500ml/1bag
= 500hr/10bag
= 50hr/bag

OBGYN
Dr MUSA MARENA
45. Begin a Pitocin infusion at 5 mu/min via IV pump for labor induction. On hand is Pitocin
40units in 1000ml Lactated Ringers. How many ml/hr will the IV run? How long does it take
to infuse the whole Pitocin? What will be the drip rate if the giving set use have a drop factor
of 60drops=1ml
= 300000ml/40000hr
= 7.5ml/hr
• Measure is time
Unit of measure is hours
hr = 1hr/60min × min/5mU × 1000mU/1U × 40U
= 40000hr/300
= 133.33hr
• Measure is time
min = 60min/hr × 0.33hr
= 19.8min
• Measure is time
Unit of measure second
sec = 60sec/min × 0.9min
= 54sec
• Total duration of bag is 133hr 19min 54sec
= 300000drops/40000min
= 7.5drops/min in
= 8drops/min
46. Magnesium sulfate 30 grams is mixed in 500 ml Lactated Ringers. Order: infuse a
maintenance dose of magnesium sulfate @ 4 grams/hour. How many ml/hr will the IV run?

OBGYN
Dr MUSA MARENA
How long will it take to infuse the whole bag? If the standard given set is used what will be
the drip rate in drops/min?
ml/hr = 500ml/30g × 4g/hr
= 2000ml/30hr
= 66.67ml/hr
• Measure is time
Unit of measure hours/bag
hr/bag = hr/4g × 30g/bag
= 30hr/4bag
= 6.5hr/bag
• Measure is time
min = 60min/hr × 0.5hr
= 60min/0.5
= 30min
• Total time/bag is 6hrs 30min
Standard giving set is 1ml = 20drops
drops/min = 20drops/ml × 500ml/50g × 4g/hr × 1hr/60mins
= 13.3drops/min
47. Your client is ordered 1 mg/hr morphine through the volumetric pump. You have made up
an intravenous bag containing 50 mg morphine in 500 mL normal saline. How many mL/hr
will you dial up on the volumetric pump?
= 500ml/50hr

OBGYN
Dr MUSA MARENA
= 10ml/hr
48. You are required to give 6 mg morphine. In your stock ampoule there is 15 mg per 1mL. How
much of the ampoule in ml will you need?
Unit of measure ml
ml = 1ml/15mg × 6mg
= 6ml/15
= 0.4ml
49. When you look at your infusions at the commencement of the shift you have 50 mg glyceryl
trinitrate (GTN) diluted in 100 mL 5% dextrose solution running at 4 mL/hr via a volumetric
pump. Calculate the dose in µg/min.
• Measure is dose
Unit of measure is mcg/ml
mcg/min = 1000mcg/1mg × 50mg/100ml × 4ml/hr × 1hr/60min
= 200000mcg/6000min
= 33.3mcg/min
50. A 1 litre infusion of NaCl 0.9% is being given over 16 hours using a standard giving set. If the
rate at which the infusion is run is 21 drops per minute, over what time will the infusion
actually run? (assume 20 drops per ml)
• Measure is time
Unit of measure hours
hr = 1hr/60min × min/20drops × 20drops/ml × 1000ml/1L × 1L/1
= 20000hr/1200
= 16.67hr
Measure is time
Unit of measure is minutes
min = 60min/1hr × 0.67hr/1
= 40.2min
Measure is time
Unit of measure second

OBGYN
Dr MUSA MARENA
sec = 60sec/min × 0.2min/1
= 12sec
• Total duration is 16hrs 40mins 12sec
51. Obstetrician order 500mg methldopa every 6hour for patent with high blood in pregnancy.
The drug is available as 250mg/tablet. How many doses per day did the patient received?
How many mg/day will the patient take? How many tablets per dose will the patient take?
How many tablets/day will the patient take?
• Measure is number
Unit of measure dose/day
dose/day =1dose/6hrs × 24hrs/day
= 24dose/6days
= 4doses/day
Unit of measure is mg/day
mg/day = 500mg/6hrs × 24hrs/day
= 12000mg/6days
= 2000mg/day
• Measure is number
Unit of measure tablet/dose
tablet/dose = tablet/250mg × 500mg/dose
= 500tablets/250dose
= 2tablets/dose
• measure is number
Unit of measure tablets/day
tablets/day = tablet/250mg × 500mg/6hrs × 24hrs/day
= 12000tablets/1500day
= 8tablets/day
52. A child weighs 22kg and is ordered 25mg/kg/day every 8 hours, stocked as 0.05g/10ml. Find
the mg/kg/per dose, the equivalent ml and the total dose over 24hrs to be given.
• Measure is dose

OBGYN
Dr MUSA MARENA
Unit of measure mg/kg/dose
mg/kg/dose = 25mg/kg/day × 1day/24hrs × 8hr/dose
= 200mg/kg/24doses
= 6.3mg/kg/dose
• Measure is dose
Unit of measure ml/kg/dose
ml/kg/dose = 10ml/0.05g × 1g/1000mg × 25mg/kg/day × 1day/24hrs ×
8hr/dose
= 2000ml/kg/1200dose
= 1.67ml/kg/dose
• Measure is dose
Unit of measure mg/24hrs
mg/24hrs = 25mg/kg/day × 22kg/1 × 1day/24hrs
= 550mg/24hrs
53. A 70kg patient requires Dobutamine at a dose of 10mcg/kg/min and Dopamine
2.5mcg/kg/min.
a. Calculate the dose of each drug in (i) mg/min (ii) mg/hr
b. Calculate the dose in mls per hour if the infusions are prepared as below:
Dobutamine 250mg in 50mls dextrose 5%
Dopamine 200mg in 50mls dextrose 5%
The patient's urine output improves and his dose of Dobutamine is reduced to 8mcg/kg/min.
c. Calculate his new dose in mls/hr.
Dobutamine
mg/min = 1mg/1000mcg × 10mcg/kg/min × 70kg
= 700mcg/1000min
= 0.7mg/min
mg/hr = 1mg/1000mcg × 10mcg/kg/min × 70kg × 60min/hr
= 42000mg/1000hr

OBGYN
Dr MUSA MARENA
= 42mg/hr
• Dopamine
Unit of measure is mg/min
mg/min = 1mg/1000mcg × 2.5mcg/kg/min × 70kg
= 175mg/1000min
= 0.175mg/min
mg/hr = 1mg/1000mcg × 2.5mcg/kg/min × 70kg × 60min/hr
= 10500mg/1000hr
= 10.5mg/hr
• Dobutamine
ml/hr = 50ml/250mg × 1mg/1000mcg × 10mcg/kg/min 70kg × 60min/hr
= 2100000ml/250000hr
= 8.4ml/hr
= 8ml/hr
• Dopamine
ml/hr = 50ml/200mg × 1mg/1000mcg × 2.5mcg/kg/min × 70kg × 60min/1hr
= 525000ml/200000hr
= 2.625ml/hr
= 3ml/hr
• Dopamine
ml/hr = 50ml/250mg × 1mg/1000mcg × 8mcg/kg/min × 70kg × 60min/hr
= 1.680000ml/250000hr

OBGYN
Dr MUSA MARENA
= 6.72ml/hr
= 7ml/hr
54. A patient is being given Chloramphenicol eye drops 0.5% for an eye infection.
a. How much drug is contained in 5ml?
b. How much drug is contained in 1 drop if each 1ml = 20 drops
Unit of measure mg
0.5% chloramphenicol means 0.5g in 100ml
mg = 1000mg/1g × 0.5g/100ml × 5ml
= 2500mg/100
= 25mg
Unit of measure mg/drop
0.5% chloramphenicol means 0.5g in 100ml
mg/drop = 1000mg/1g × 0.5g/100ml × 1ml/20drop
= 500mg/2000drops
= 0.25mg/drop
55. What quantity of Adrenaline in mg is there in a 20ml vial of 1in 200,000 Adrenaline
Unit of measure is mg/vial
1 in 200000 adrenaline means 1g in 200000ml
mg/vial = 1000mg/1g × 1g/200000ml × 20ml/vial
= 20000mg/200000vial
= 0.1mg/vial
56. Drug J is available as 125mg and 50mg capsules. Mr N weighs 82kg and has been prescribed
12mg per kg daily in 2-3 divided doses. How would you label the bottles of capsules
• Measure is dose
mg/dose = 12mg/kg/day × 82kg/1 × 1day/3doses

OBGYN
Dr MUSA MARENA
= 984mg/3dose
= 328mg/dose
• Two tablets of 125mg (250mg) and one and half tablet of 50mg (75mg)
altogether 328mg dose
• measure is dose
mg/dose = 12mg/kg/day × 82kg × 1day/2doses
= 984mg/2dose
= 492mg/dose
• Three tablets of 125mg (375mg) and two and half tablet of 50mg (125mg)
57. The reading on a syringe driver administering drug C is 3.5mls/hr. The additive label says
'250mg in 50ml' and the patient's weight is 70kg. What dose of drug C is the patient
receiving in mcg/kg/min?
• Measure is dose
Unit of measure mcg/kg/min
mcg/kg/min = 1000mcg/1mg × 250mg/50ml × 3.5ml/hr × 1hr/60min ×
1/70kg
= 875000mcg/210000kg/min
= 4.17mcg/kg/min
58. A client is ordered 600 mg of Carbamazepine in two separate doses. Available tablets are of
150mg. How many tablets will you give per dose?
• Measure is dose
Unit of measure tablet/dose
tablet/dose = tablet/150mg × 600mg/2doses
= 600tablet/300doses
= 2tablets/dose
59. The dose to be given is 72.5 mg/day in three separate doses in a day. The stock solution
contains 50mg in 10ml. How many ml would you administer per dose and in total in a day?
• Measure is dose
Unit of measure ml/dose/day

OBGYN
Dr MUSA MARENA
ml/dose = 10ml/50mg × 72.5mg/3doses/day
= 725ml/150dose/day
= 4.83ml/dose/day
= 4.8ml/dose/day
60. Doctor order Cefazolin 350 mg IV every 4 hours. The child weighs 31 lbs. The safe dosage
range for this medication is 25-75 mg/kg/day. Is this a safe dose for this patient?
• Measure is dose
Unit of measure is mg/day
mg/day = 350mg/4hrs × 24hrs/days
= 8400mg/4days
= 2100mg/day
Minimum dose
mg/day = 25mg/kg/day × 1kg/2.2Ib × 31Ib
= 775mg/2.2day
= 352.3mg/day
Maximum dose
= 2325mg/2.2Ib
= 1056.8.7mg/day
• Dose 2100mg/day is more than maximum dose 1056.8mg/day hence the
dose is not safe
61. Doctor orders an IV drip of Dopamine for a child that weighs 78 lbs. The safe dosage range
for this medication is 5-20 mcg/kg/min. What is the safe dosage range for this child?*
• Measure is safe dose
Minimum dose
mcg/min = 5mcg/kg/min × 1kg/2.2Ib × 78Ib
= 390mcg/2.2min
= 177.3mcg/min
maximum dose

OBGYN
Dr MUSA MARENA
mcg/kg/min = 20mcg/kg/min × 1kg/2.2Ib × 78Ib
= 1560mcg/2.2min
= 709.1mcg/min
• Therefore Safe dose is 177.3 -709.1mcg/min
62. During cesarean section the Anesthetist administered 0.25mg of fentanyl as part of spinal
anesthesia. A vial of fentanyl contained 1mg/ml. how much volume in ml of fentanyl was
administered by the Anesthetist?
Unit of measure is ml
ml = ml/1mg x 0.25mg
= 0.25ml/1
= 0.25ml
63. Anesthesiologist gave 2.5ml of bivupacaine as spinal anesthesia to a women undergoing
caesarean section. The bivupacaine is available as 0.5% of bivupacaine vial. How many
milligrams did the pregnant women received?
Unit of measure is mg
Percentage means grams in 100ml of solution
0.5% of bivupacaine means 0.5g buvipacaine per 100ml of solution
mg = 1000mg/1g × 0.5g/100ml × 2.5ml/1
= 1250mg/100
= 12.5mg
64. Obstetrician ordered 4g of MgSO4 in 200ml NS to be given over 30min. The MgSO4 is
available in 50% in 50ml of MgSO4. How much should the midwife regulate infusion pump in
ml/hr? What is the drip rate in drops/min if the drop factor is 20drops/ml? What is the
dosage of MgSO4 in mg/min? What is the concentration of MgSO4 in mg/ml?
ml/hr = 200ml/30min × 60min/hr
= 12000ml/30hr

OBGYN
Dr MUSA MARENA
= 4000ml/hr
drops/min = 20drops/ml × 200ml/30min
= 4000drops/30min
= 133.33drops/min
= 133drops/min
• Measure is dose
mg/min = 1000mg/1g × 4g/30min
= 4000mg/30min
= 133.33mg/min
= 133.3mg/min
• Measure is concentration
Unit of measure mg/ml
mg/ml = 1000mg/1g × 4g/200ml
= 4000mg/200ml
= 20mg/ml
65. The Obstetrician ordered 20ml of 20% MgSO4. The MgSO4 available in 50ml of 50%. How
much volume in ml should the midwife add to NS to prepare the solution?
• Percentage means amount in grams per 100ml of solution
• 20% MgSO4 means 20grams MgSO4 in 100ml of solution
• 50% means 50grams MgSO4 in 100ml of solution
• Amount of MgSO4 used
Unit of measure mg
g =20g/100ml × 20ml/1
= 400mg/100
= 4g
• The volume MgSO4 containing 4g

OBGYN
Dr MUSA MARENA
Unit of measure ml
ml = 100ml/50g × 4g/1
= 400ml/50
= 8ml
66. Doctor orders 300 mg of Zmax once a day for a child that weighs 72 lbs. The safe dose range
for this medication is 10-12 mg/kg/day. Is this a safe dose for this patient?
• Min dose
• Measure is dose
Unit of measure mg/day
= 720mg/2.2day
= 327.3mg/day
• Max dose
• Measure is dose
= 864mg/2.2Ib
= 392.7mg/day
• Dosage range is 327.3 - 392.7mg/day which is less than 30mg
• The dose of 300mg is not safe
67. Doctor orders Zithromax for a child that weighs 82 lbs. The safe dose range for this
medication is 10-12 mg/kg/day. What is the maximum safe daily dose for this child?
mg/day = 12mg/kg/days × 1kg/2.2Ib × 82Ib
= 984mg/2.2day
= 447.3mg/day

OBGYN
Dr MUSA MARENA
68. Obstetrician order Pitocin 5mU/min. The L & D protocol is 5unit of Pitocin in 500ml NS. At
what rate should regulate the infusion pump in ml/hr to give 15drops/min of Pitocin solution
to the patient? What is the drop factor of the giving set in drops/ml?
ml/hr = 500ml/5U × 1U/1000mU × 5mU/min × 60min/1hr
= 150000ml/5000hr
= 30ml/hr
Unit of measure is drops/ml
drops/ml = 15drops/min × min/5mU × 1000mU/1U × 5U /500ml
= 75000drops/2500ml
= 30drops/ml
69. Midwife administer Pitocin solution with infusion pump at 30ml/hr. The L & D protocol is
10unit in 500ml of D5W. The drip rate is 10drop/min. How much Pitocin was the patient
receiving in mU/min? What is the drop factor in drops/ml?
• Measure is dose
mU/min = 1000mU/1U × 10U/500ml × 30ml/hr × 1hr/60mins
= 300000mU/30000min
= 10mU/min
drops/ml = 10drops/min × 60min/hr × 1hr/30ml
= 600drops/30ml
= 20drops/ml
70. The midwife regulates infusion pump at 30ml/hr. The drip rate is 10drops/min if the patient
is receiving 15mu/min of Pitocin. What is the concentration of the Pitocin solution in
mU/ml? What is the drop factor of the given set in drops/ml?
Unit of measure is mU/ml

OBGYN
Dr MUSA MARENA
mU/ml = 15mU/min × 60min/1hr × 1hr/30ml
= 900mU/30ml
= 30mU/ml
• Measure is drop Factor
Unit of measure is drops/ml
drops/ml = 10drops/min × 60min/1hr × 1hr/30ml
= 600drops/30ml
= 20drops/m
71. The Midwife regulates the Pitocin infusion at 100ml/hr. The drop factor is 10drops/ml. The
patient is receiving 10mu/min of Pitocin. What is the drip rate in drops/min? What is the
concentration of the Pitocin solution in mU/ml
• Measure is dose
= 1000drops/60min
= 16.7drops/min
= 17drops/min
Unit of measure mU/ml
mU/ml = 10mU/min × 60min/hr × 1hr/100ml
= 600mU
= 6mU/ml
72. The midwife regulates the drip at 25drops/min so as to be administer 12.5mU/min if the
drip factor is 20drops/ml what is the concentration of the Pitocin solution in mU/ml? What is
the flow rate in ml/hr?
Unit of measure is mU/ml
mU/ml = 12.5mU/min × 1min/25drops × 20drops/ml
= 250mU/25ml
= 10mU/ml

OBGYN
Dr MUSA MARENA
• Measure is the flow rate
ml/hr = 1ml/20drops × 25drops/min × 60min/hr
= 1500ml/20hr
= 75ml/hr
73. A midwife regulated an infusion pump at 30ml/hr. The labour ward protocol 10unit of
Pitocin in 500ml of D5W and drop factor is 15drops/ml. How much Pitocin is the patient
receiving in mU/min? What is the drip rate in drops/min?
• Measure is dose
mU/min = 1000mU/1U × 10U/500ml × 30ml/hr × 1hr/60min
= 300000mU/30000ml
= 10mU/min
= 450drops/60min
= 7.5drops/min
= 8drops/min
74. In active management of labour the obstetrician ordered Pitocin starting at 5mU/min. L & D
protocol 10unit of Pitocin in 500ml NS and drop factor 20drops/ml. At what rate in
drops/min should the nurse regulate the drip? What will be the flow rate in ml/hr?
= 50000drops/10000min
= 5drops/min
• Measure is the flow rate

OBGYN
Dr MUSA MARENA
= 150000ml/10000hr
= 15ml/hr
75. Upon taking over of her shift duty the nurse discover Pitocin drip is regulated at
40drops/min. The drop factor is 15drops/min and L & D protocol is 20units Pitocin in 1000ml
of D5W. How much Pitocin was the patient receiving in mU/min? What is the flow rate in
ml/hr?
• measure is dose
Unit of measure is mU/min
= 800000mU/15000min
= 50mU/min
= 2400ml/15hr
= 160ml/hr
76. Physician ordered for post cesarean section patient was 40unit of Pitocin in 1000ml of NS to
administer 30mU/min. how many drops should the nurse regulate the drip using the
microdrip set?
=1800000drops/40000min
= 180drops/min
77. 40 units oxytocin in 1000ml lactated Ringers is infusing at 80mU/min. How many ml/hr is the
patient receiving?
• The measure is Flow rate
ml/hr = 1000ml/40U × 1U/1000mu × 80mU/min × 60min/1hr
= 4800000ml/40000min

OBGYN
Dr MUSA MARENA
= 120ml/hr
78. The physician has ordered 500ml D5W with 10units IV oxytocin. Begin at 2mU/min and then
increase by 1mU/min every 30minutes until regular uterine contractions begin. Maximum
dose 30mU/min
a. What is the IV flow rate for the beginning infusion?
b. What is the IV drip rate for the maximum infusion using 20drop/ml giving set?
= 30000ml/10000hr
= 3ml/hr
Unit of measure is drops/mins
= 300000ml/10000min
= 30ml/min
79. Physician Ordered 2mU/min. Pitocin available with 10units/ml. Protocol on L & D unit mix 2
vials per 1000ml NS. What should the nurse set the IV pump at?
• 1 vial contains 10unit of oxytocin
• Hence 2 vials will contain 20units
• The measure is flow rate
= 120000ml/20000hr
= 6ml/hr
80. Magnesium Sulphate 40grams in 1000ml lactated Ringers at a rate of 2g/hr. What is the
pump rate?
• The measure is flow rate
ml/hr = 1000ml/40g × 2g/hr

OBGYN
Dr MUSA MARENA
= 2000ml/40hr
= 50ml/hr
81. Patient received 2ml of Buvipacaine as spinal anesthesia. The vial is 10mls of 0.5%
buvipacaine. How many mg of buvipacaine was administered to the patient?
Unit of measure is mg
mg = 1000mg/1g × 0.5g/100ml × 2ml
= 1000mg/100
= 10mg
• Note: % means grams per 100ml
• Therefore 0.5% buvipacaine means 0.5g buvipacaine in 100ml of solution
82. 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 drops per min should the drip set using the
microdrip?
drops/min = 60drops/ml × 100ml/100unit × 5unit/hr × 1hr/60min
= 30000drops/6000mins
= 5drops/min
83. 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.
Unit of measure is mg/dose
mg/dose = 200mg/kg/day ×1kg/2.2Ib × 22Ib × 1day/24hrs × 6hrs/dose
= 26400mg/52.8doses
= 500mg/dose
84. The obstetrician ordered to infuse Syntocinon at a rate of 30drops/min using a standard
given set. The Syntocinon is available as 20units in 500ml of NS. How much Syntocinon is
infuse into the patient in milliunit/min? How much is the rate of flow of solution into the

OBGYN
Dr MUSA MARENA
patient in ml/hr? How long will it take for infusion to complete in hours? show the work to
your answer
• Measure is dose
Unit of measure is milliunit/min
milliunit/min = 1000milliunit/1unit × 20unit/500ml × 1ml/20drops ×
30drops/min
= 600000milliunit/10000min
= 60milliunit/min
= 1800ml/20hr
= 90ml/hr
• Measure is time
Unit of measure is hours
hr = 1hr/60min × min/30drops × 20drops/ml × 500ml
= 10000hr/1800
= 5.6hrs
85. Calculate the number of ova that can be fertilize by a single ejaculate.
Unit of measure zygote/ejaculate
Zygote/ejaculate = zygote/1ovum × 1ovum/1sperm × 20000000sperm/1ml ×
1.5ml/ejaculate
= 35000000zygote/ejaculate
= 35millionzygote/ejaculate
86. 20units oxytocin in 500ml Lactated Ringers is infusing at 45ml/hr. How many mU/min is the
patient receiving? What would be the drip rate using microdrip?

OBGYN
Dr MUSA MARENA
mU/min = 1000mU/1U × 20U/500ml × 45ml/hr × 1hr/60min
= 900000mU/30000min
= 30mU/min
drops/min = 60drops/1ml × 45ml/1hr × 1hr/60min
= 2700drops/60min
= 45drops/min
87. It is time to increase the oxytocin infusion to 5mU/min. If the infusion has 30 units oxytocin
in 500ml Lactated Ringers, what will the pump rate be?
= 150000ml/30000hr
= 5ml/hr
88. Immediately after delivery, the provider ordered the nurse to bolus a patient with 10 units
of Pitocin over 30 minutes. The pre-mixed infusion is 30 units of oxytocin in 500ml 0.9% NSS.
What is the volume to be infused?
Unit of measure ml
ml = 500ml/30U × 10U/1
= 5000ml/30
= 166.67ml
89. You are ordered to give misoprostol 25mcg for cervical ripening. The dosage strength in the
tablet is 100mcg. Calculate the correct dosage for this med.

OBGYN
Dr MUSA MARENA
Unit of measure tablets
tablet = 1tablet/100mcg × 25mcg/1
= 25tablet/100
= 1tablet/4
90. The nurse is initiating an oxytocin induction as ordered by the provider. The protocol at her
hospital is to start the infusion at 1mU/min, and increase by 2mU/min every 60minutes until
adequate labour is achieved. At what rate (ml/hr) will the nurse set the pump if the pre-
mixed bag has 30 units of oxytocin in 500ml of LR?
= 30000ml/30000hr
= 1ml/hr
91. The gynaecologist ordered methotrexate 50mg/m2
for medical treatment of unruptured
ectopic pregnancy if the patient weighs 140Iband her height 5ft 8in. how much volume in ml
of methotrexate will be administered. Methotrexate is available as 250mg in 20mls.
Unit of measure ml
• 𝐵𝑆𝐴 = √
ℎ𝑡(𝑐𝑚)×𝑤𝑡 (𝑘𝑔)
3600
• Patient's height = 5ft 6in
in = 12in/1ft × 5ft + 8in
= 68in
Patient's ht (cm) = 2.5cm/1in × 68in
= 170cm
Patient wt (kg) = 1kg/2.2lb × 140lb
= 140kg/2.2
= 63.64kg
• 𝐵𝑆𝐴 = √
170𝑐𝑚 ×63.64𝑘𝑔
3600
= √
10818.8
3600
= √3
= 1.73m2
ml = 20ml/250mg × 50mg/m2
× 1.73m2
/1
= 1730ml/250
= 6.92ml
92. Fertility specialist performs IUI for a couple with unexplained infertility using 1.2ml of wash
semen. If the concentration is 60million sperm per ml. how many spermatozoa where infuse
into the uterus.

OBGYN
Dr MUSA MARENA
Unit of measure spermatozoa
Sperm = 80×106sperm/ml × 1.2ml/1
= 96×106sperm
93. 30YO lady undergoing ovarian stimulation is to receive follistim 150U/dose/day. How many
units of follistim will the patient received if the cycle is last 13days. Each cartridge contains
300U and cost $350. How many cartridges will the patient use? How much money will the
couple spend?
Unit of measure units
U = 150U/dose/day × 1dose/1 × 13days/1
= 1950U/1
= 1950U
Unit of measure cartridge
Cartridge = 1 cartridge/300U × 150U/dose/day × dose/1 × 13days/1
= 1950cartridge/300
= 6.5cartridges
= 7 cartridge
Number of cartridges will be 7 because one cannot buy half cartridge
Unit of measure dollar
$ = $350/300U × 150U/dose/day × dose/1 × 13days
=$682500/300
= $2275
In reality the cost will be
Unit of measure is dollar
$ = $350/1cartridge × 7cartridge/1
= $2450
94. Cisplatin is given as adjuvant for treatment of ovarian cancer. Gynaeocologist ordered
80mg/m2
/day. Patient weighs 95Ib and height 6ft 2in. Cisplatin is available as 100mg in
100ml. how many ml will the nurse withdrawn from the vial? How many mg should the
patient be given?
• 𝐵𝑆𝐴 = √
ℎ𝑡(𝑐𝑚)×𝑤𝑡 (𝑘𝑔)
3600
• Patient's height = 6ft 2in
in = 12in/1ft × 6ft + 2in
= 74in
Patient's ht (cm) = 2.5cm/1in × 74in
= 185cm
Patient wt (kg) = 1kg/2.2lb × 95lb
= 95kg/2.2

OBGYN
Dr MUSA MARENA
= 43.18kg
• 𝐵𝑆𝐴 = √
185𝑐𝑚 ×43.18𝑘𝑔
3600
= √
7988.3
3600
= √2.21
= 1.47m2
ml = 100ml/100mg × 80mg/m2
× 1.47m2
= 11760ml/100
= 117.6ml
95. Patient presented with diagnosis of persistent mole after evacuation of complete molar
pregnancy 3moths ago. The doctor ordered cyclophosphamide 20mg to given over 6hrs.
how many mcg/min will the patient if premix contains 150mg in 100ml. how much fluid will
the patient receive? What would be the drip rate using microdip set to administer the
medication?
mcg/min = 1000mcg/1mg × 20mg/6hrs × 1hr/60min
= 20000mcg/360min
= 55.6mcg/min
Unit of measure ml
ml = 100ml/150mg × 20mg/1
= 2000ml/150
= 13.33ml
= 13.3ml
• measure is drip rate
unit of measure drops/min
microdrip set implies 60drops are delivered every milliliter given
drops/min = 60drops/ml × 100ml/150mg × 20mg/6hrs × 1hr/60mins
= 120000drops/54000min
= 2.2drops/min
= 2drops/min
96. You have ketamine 500mg in 5mL. You want to prepare a 10mL syringe with 10mg/mL.
Unit of measure mg
mg = 10mg/ml × 10ml
= 10mg/10
= 1ml
• You add 9ml of diluent by withdrawing 1ml of ketamine solution into
10ml syringe and withdraw diluent up to 10ml mark
97. Epidural syringe preparation. Available: bupivacaine 0.25% (2.5 mg/mL), fentanyl 50mcg/mL,
and sterile diluent. Desired: A 60mL syringe, containing 0.0625% (this is often called 1/16 %)
bupivacaine with fentanyl 5mcg/mL.

OBGYN
Dr MUSA MARENA
• Ketamine
• Measures is weight
Unit of measures mg
mg = 1000mg/1g × 0.0625g/100ml × 60ml/1
= 3750mg/100
= 37.5mg
• Measures is volume
Unit of measures ml
ml = ml/2.5mg × 37.5mg/1
= 37.5ml/2.5
= 15ml
• Fentanyl
Measures is weight
Unit of measures mg
mg = 1mg/1000mcg × 5mcg/ml × 60ml/1
= 300mg/1000
= 0.3mg
• Measures is volume
Unit of measure ml
ml = ml/50mcg × 1000mcg/1mg × 0.3mg/1
= 300ml/50
= 6ml
• 15ml of ketamine is withdrawn into 60ml syringe then 6ml of fentanyl
and finally the diluent upto 60ml mark
98. What is the dose mg/min of lidocaine (1 gm in 250 mL) running at 15 mL/hr?
• Measures is dosage
mg/min = 1000mg/1g × 1g/250ml × 15ml/1hr × 1hr/60min
= 15000mg/15000min
= 1mg/min
99. What rate should you set to deliver dopamine 3 mcg/kg/min for a patient who weighs 70kg?
The dopamine concentration is 400mg/250mL.
• Measures is flow rate
Unit of measures ml/hr
ml/hr = 250ml/400mg × 1mg/1000mcg × 3mcg/kg/min × 70kg/1 ×
60min/hr
= 3150000ml/400000hr
= 7.875ml/hr
= 7.9ml/hr

OBGYN
Dr MUSA MARENA
100. If you want to create a remifentanil infusion at the recommended adult dilution of
50 mcg/mL, and it is supplied as a vial containing 1 mg powder, how many mL of diluent
should you add to the vial?
• Measure is amounts
Unit of measures ml
ml = ml/50mcg × 1000mcg/1mg × 1mg/1
= 1000ml/50
= 20ml
Diluent to be added is 20ml
101. Order: Morphine gr 1/10 Available: Morphine 10mg/mL How many mL will the nurse
give?
Unit of measure ml
One grain (gr) equals 60mg (64.79891mg)
ml = ml/mg × 60mg/1gr × 1gr/10
= 60ml/100
= 6ml
102. You have ephedrine 50mg in 1mL. You want to prepare a syringe with 10mg/mL.
What size syringe should you use?
Unit of measures ml
ml = ml/10mg × 50mg/1
= 50ml/10
= 5ml
Size of syringe is 5ml
103. 32YO been investigated for tubal infertility via laparoscopy. The rate of CO2
insufflation was 1000ml/min. the surgery lasted for 3hrs. how much CO2 was insufflated into
the patient's peritoneal cavity?
ml = 1000ml/min × 60min/1hr × 3hr/1
= 180000ml/1
= 180000ml
104. A woman is admitted to the labor room with a diagnosis of preterm labor. She states
that she has not seen a physician because this is her third baby and she “knows what to do
while she is pregnant.” Her initial workup indicates a gestational age of 32 weeks, and she
tests positive for Chlamydia and Strep-B. Her vital signs are: T 100° F; P 98; R 18; B/P
140/88mmHg; and the fetal heart rate is 140–150. The orders include the following:
▪ NPO

OBGYN
Dr MUSA MARENA
▪ IV fluids: D5/RL 1,000 mL q8h
▪ Electronic fetal monitoring
▪ Vital signs q4h
▪ Dexamethasone 6 mg IM q12h for 2 doses
▪ Brethine (terbutaline sulfate) 0.25 mg subcutaneous q30 minutes for 2h
▪ Rocephin (ceftriaxone sodium) 250 mg IM stat
▪ Penicillin G 5 million units IVPB stat; then 2.5 million units q4h
Zithromax (azithromycin) 500 mg IVPB stat and daily for 2 days
a. Calculate the rate of flow for the D5/RL in mL/h.
b. The label on the dexamethasone reads 8 mg/mL. How many milliliters will you
administer?
c. The label on the terbutaline reads 1 mg/ml. How many milliliters will you administer?
d. The label on the ceftriaxone states to reconstitute the 1 g vial with 2.1 mL of sterile
water for injection, which results in a strength of 350 mg/mL. How many milliliters will
you administer?
e. The instructions state to reconstitute the penicillin G (use the minimum amount of
diluent), add to 100 mL D5W, and infuse in one hour. The drop factor is 10drops/ml.
What is the rate of flow in gtts/min? The label on Penicillin G reads pfizerpen (penicillin
G Potassium) for injection 5million units. Additional information 18.2ml diluent added
gives 250 000units/ml, 8.2ml diluent added gives 500 000units/ml and 3.2ml diluent
added gives 1 000 000units/ml of solution.
f. The instructions for the azithromycin state to reconstitute the 500 mg vial with 4.8 mL
until dissolved, and add to 250 mL of D5W and administer over at least 60 minutes.
What rate will you set the infusion pump if you choose to administer the medication
over 90 minutes? If drop factor is 15drops/ml, what is the drip rate?
ml/hr = 1000ml/8hr
= 125ml/hr
Unit of measure milliliter
ml = 1ml/8mg × 6mg/1
= 0.75ml/1
= 0.75ml
ml = 1ml/1mg × 0.25mg/1
= 0.25ml/1
= 0.25ml
ml = 1ml/350mg × 250mg/1

OBGYN
Dr MUSA MARENA
= 250ml/350
= 0.714ml
= 0.7ml
drops/min = 10drops/ml × 100ml/1hr × 1hr/60min
= 1000drops/60min
= 16.67drops/min
=17drops/min
ml/hr = 250ml/90min × 60min/1hr
= 15000ml/90hr
=166.67ml/hr
ml/hr = 15drop/ml × 250ml/90min
= 3750drops/90min
= 41.67drops/min
= 42drops/min
105. The patient continues to have uterine contractions, and a new order has been
written:
Magnesium sulfate 4g IV bolus over 20minutes, then 1g/h.
The label on the vial of magnesium sulphate is 50% w/v and IV bag states magnesium sulfate 40g
in 1,000ml.
a. What is the rate of flow in mL/h for the bolus dose? If the drop factor is 20gtt/mL, determine
the drip rate?
b. What is the rate of flow in mL/h for the maintenance dose? If the drop factor is 60gtt/min,
determine the flow rate in gtt/min?
c. What volume of magnesium sulphate was infused as withdrawn for the bolus and how many
mililitres of magnesium sulphate was place in the IV bag?
ml/hr = 1000ml/40g × 4g/30min × 60min/1hr
= 240000ml/1200hr
= 200ml/hr
drops/min = 20drops/ml × 1000ml/40g × 4g/30min × 60min/1hr

OBGYN
Dr MUSA MARENA
= 4800000drops/1200min
= 4000drops/min
ml/hr = 1000ml/40g × 1g/hr
= 1000ml/40hr
= 25ml/hr
drops/min = 60drops/ml × 1000ml/40g × 1g/hr × 1hr/60min
= 25drops/min
• measure is volume
ml = 1000ml/40g × 4g/1
= 4000ml/40
= 100ml
• measure is volume
50% w/v means 50g of magnesium sulphate in 100ml of solution
ml = 100ml/50g × 4g/1
= 400ml/50
= 8ml
106. The patient continues to have contractions and her membranes rupture. The
following orders are written:
■ Discontinue the magnesium sulfate.
■ Pitocin (oxytocin) 10units/1,000ml RL, start at 0.5mIU/min increases by 1mU/min q20
minutes.
■ Stadol (butorphanol tartrate) 1mg IVP stat.
a. What is the rate of flow in mL/h for the initial dose of Pitocin? The drop factor is
60mcgtt/ml. Calculate the flow rate in gtt/min
b. The Pitocin is infusing at 9mL/h. How many mU/h is the patient receiving? Find the drip
rate if the drop factor is 10gtt/mL?
c. What would be the drip rate after 1hr of initiating Pitocin using drop factor of 15
d. The vial of butorphanol tartrate is labeled 2mg/ml. How many milliliters will you
administer?
ml/hr = 1000ml/10unit × 1unit/1000mIU × 0.5mIU/min × 60min/1hr

OBGYN
Dr MUSA MARENA
= 30000ml/10000hr
= 3ml/hr
drops/min = 60drops/ml × 1000ml/10unit × 1unit/1000mIU × 0.5mIU/1min
= 30000drops/10000min
= 3drops/min
Unit of measure mU/hr
mU/hr = 1000mU/1unit × 10unit/1000ml × 9ml/hr
= 90000mU/1000hr
= 90mU/hr
drops/min = 10drops/ml × 9ml/1hr × 1hr/60min
= 90drops/60min
= 1.5drops/min
= 2drops/min
Starting dose 0.5mU/min
Increment is 1mU every 20min
Hence by 1hr there will be 3 increment and dose will be 3.5mU/min
drops/min = 15drops/ml × 1000ml/10unit × 1unit/1000mU × 3.5mU/min
= 52500drops/10000min
= 5.25drops/min
= 5drops/min
ml = 1ml/2mg × 1mg/1
= 1ml/2
= 0.5ml
107. Postpartum the woman developed postpartum haemorrhage. The following orders
are written
■Massage uterus for contraction q15min, continuous monitoring vitals.
■Pitocin 20unit in 500ml NS, giving at 20miU/min
■Ergometrin 1mg IM stats
■Tablets Misoprostol 800mcg PR stats
■Transfuse 2units of whole blood over 6hours.

OBGYN
Dr MUSA MARENA
a. What is the flow rate of the Pitocin drip? Using IV set of 20drops/ml at what drip rate
would the nurse regular the drip?
b. Label on the Ergometrin ampoule 0.5mg/ml. how many millileters will the nurse
administer?
c. Misoprostol packet label 200mcg/tablets. How many tablets should be inserted PR?
d. A unit of blood has 400ml. if the blood giving set gives 15drops/ml what rate should the
flow rate hence calculate the drip rate be regulated
ml/hr = 500ml/20unit × 1unit/1000mIU × 20mIU/min × 60min/1hr
= 600000ml/20000hr
= 30ml/hr
drops/min = 20drops/ml × 500ml/20unit × 1unit/1000mIU × 20mIU/1min
= 200000drops/20000min
= 10drops/min
ml = 1ml/0.5mg × 1mg/1
= 1ml/0.5
= 2ml
tablets = 1tablet/200mcg × 800mcg/1
= 800tablet/200
= 4tablets
ml/hr = 400ml/1unit × 2unit/6hr
= 800ml/6hr
= 133.33ml/hr
= 133.3ml/hr
drops/min = 15drops/ml × 400ml/1unit × 2unit/6hr × 1hr/60min
= 12000drops/360min
= 33.33drops/min
= 33drops/min

OBGYN
Dr MUSA MARENA
108. 3 days later patient develop fever chill rigors foul smelly vaginal discharge and
uterine tenderness. Diagnosis of puerperal sepsis was made and the following order are
written
■Tablets paracetamol 1g every 6hours
■IV Clindamycin 900mg every 8hours
■IV Gentamycin 1.5mg/kg every 8hours
■IV 500mlof NS over 30minutes then maintenance of 3liters over the next 24hrs
a. Sachet of paracetamol has 250mg/tablet. How many tablets should the patient receive?
b. Label on the clindamycin vial is 150mg/ml. how many milliters should the patient receive
each dose?
c. Gentamycin vial label 20mg/ml. the patient weighs 65kg. How many milligrams is the
patient supposed to receive hence how many milliliter of gentamycin should be given to
the patient for each dose?
d. If the drop factor of the set is 15drops/ml. what is the flow rate for the maintenance.
What should be the drip rate? If the patient weighs 75kg what should be appropriate
maintenance fluid requirement?
tablets = 1tablet/250mg × 1000mg/1g × 1g/1
= 1000tablets/250
= 4tablets
Unit of measure milliliters/dose
Ml/dose = 1ml/150mg × 900mg/dose
= 900ml/150dose
= 6ml/dose
Unit of measure mg
mg = 1.5mg/1kg × 65kg/1
= 97.5mg
ml = 1ml/20mg × 1.5mg/1kg × 64kg/1
= 97.5ml/20
= 4.875ml
= 4.9ml
ml/hr = 1000ml/1L × 3L/24hrs
= 3000ml/24hr
= 125ml/hr

OBGYN
Dr MUSA MARENA
drops/min = 15drops/ml × 1000ml/1L × 3L/24hr × 1hr/60min
= 31.25drops/min
= 31drops/min
109. 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 2units of blood
▪ Admission weight 164lb
▪ Lactated Ringers IV at 100ml/hr
▪ Zidovudine 2mg/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 1g IVPB × 1 dose 1 hour prior to C-section
▪ Metoclopramide (Reglan) 10mg IV push every 6 hours prn for nausea and vomiting
▪ Hydrocodone 5mg and acetaminophen 325mg PO two tablets every 4 hours prn for
moderate to severe pain
▪ Docusate sodium 100mg PO two capsules bid
Identify the orders that require calculations.
Set up and solve each problem using dimensional analysis.
a. Calculate the weight of the patient in kilograms.
b. Calculate how many mL/hr to set the IV pump to infuse zidovudine 2mg/kg over 1 hour.
Supply: Zidovudine 200mg/50ml D5W.
c. Calculate mL/hr to set the IV pump to infuse zidovudine 1mg/kg/hr. Supply: Zidovudine
400mg/100ml D5W.
d. Calculate mL/hr to set the IV pump to infuse cefazolin 1g IV. Supply: Cefazolin (Ancef)
1000mg/100ml D5W to be administered over 30minutes.
e. Calculate how many mL of metoclopramide 10mg will be given IV push over 2 minutes.
Supply: Reglan 5mg/ml.
Unit of measure kilogram
kg = 1kg/2.2lb × 164mg/1
= 164kg/2.2
= 74.5kg
ml/hr = 50ml/200mg × 2mg/kg/1hr × 1kg/2.2lb × 164lb
= 16400ml/440hr

OBGYN
Dr MUSA MARENA
= 37.27ml/hr
= 37.3ml/hr
ml/hr = 100ml/400mg × 1mg/kg/1hr × 1kg/2.2lb × 164lb
= 16400ml/880hr
= 18.64ml/hr
= 18.6ml/hr
ml/hr = 100ml/1000mg/30min × 1000mg/1g × 1g/1 × 60min/1hr
= 6000000ml/30000hr
= 200ml/hr
ml = ml/5mg × 10mg
= 10ml/5
= 2ml
110. A 14-year-old patient is admitted to the hospital with weight loss and dehydration
secondary to hyperemesis gravidarum. The orders from the physician include:
▪ Bed rest with bathroom privileges
▪ Obtain weight daily
▪ Vital every 4h
▪ Test urine for ketones
▪ Urinalysis, complete blood count, electrolytes, liver enzymes, and bilirubin
▪ NPO for 48hr, then advance diet to clear liquid, full liquid, and as tolerated
▪ IV D5 1–2 NS at 150ml/hr for 8hr, then decrease to 100ml/hr
▪ Observe for signs of metabolic acidosis, jaundice, or hemorrhage
▪ Monitor intake and output
▪ Droperidol (Inapsine) 1mg IV every 4h prn for nausea
▪ Metoclopramide (Reglan) 20mg IV in 50l of D5W to infuse over 15min
▪ Diphenhydramine (Benadryl) 25mg IV every 3h prn for nausea
▪ Dexamethasone (Decadron) 4mg IV every 6h
a. Calculate gtt/min using macrotubing (20gtt/mL) to infuse 150ml/hr, then 100mL/hr.
b. Calculate how many mL of droperidol the patient will receive IV.Supply: 2.5mg/mL
c. Calculate mL/hr to set the IV pump to infuse metoclopramide (Reglan) 20mg in 50mL of
D5W to infuse over 15min.
d. Calculate how many mL of diphenhydramine (Benadryl) the patient will receive IV.
Supply: 1mg/mL.
e. Calculate how many mL of dexamethasone (Decadron) the patient will receive IV Supply:
4mg/mL

OBGYN
Dr MUSA MARENA
= 3000drops/60min
= 50drops/min
Drops/min = 20drops/ml × 100ml/hr × 1hr/60min
= 2000drops/60min
= 33.33drops/min
= 33drops/min
ml = ml/2.5mg × 1mg/1
= 1ml/2.5
= 0.4ml
= 3000ml/15hr
= 200ml/hr
ml = ml/1mg × 25mg
= 25ml
ml = ml/4mg × 4mg
= 4ml/4
= 1ml
111. A nulliparous female is admitted to the hospital with pregnancy-induced
hypertension. The orders from the physician include:
▪ Complete bed rest in left lateral position
▪ Insert Foley catheter and check hourly for protein and specific gravity
▪ Daily weight
▪ Methyldopa (Aldomet) 250 mg PO tid
▪ Hydralazine (Apresoline) 5 mg IV every 20 min for blood pressure over 160/100
▪ Complete blood count, liver enzymes, chemistry panel, clotting studies, type and
crossmatch, and urinalysis
▪ Magnesium sulfate 4 g in 250 mL D5LR loading dose to infuse over 30 min

OBGYN
Dr MUSA MARENA
▪ Magnesium sulfate 40 g in 1000 mL LR to infuse at 1 g/hr
▪ Keep calcium gluconate and intubation equipment at the bedside
▪ Nifedipine (Procardia) 10 mg sublingual for blood pressure over 160/100 and repeat in
15 min if needed.
▪ Keep lights dimmed and maintain a quiet environment
▪ Monitor blood pressure, pulse, and respiratory rate, fetal heart rate (FHR) contractions
every 15 to 30 min, and deep tendon reflexes (DTR) hourly
▪ Monitor intake and output, proteinuria, presence of headache, visual disturbances, and
epigastric pain hourly
▪ Restrict hourly fluid intake to 100 to 125mL/hr
a. Calculate how many tablets of methyldopa (Aldomet) will be given PO. Supply:
500mg/tablet.
b. Calculate how many mL of hydralazine (Apresoline) will be given IV. Supply: 20mg/mL
c. Calculate mL/hr to set the IV pump to infuse magnesium sulfate 4 g in 250mL D5W
loading dose to infuse over 30min.
d. Calculate mL/hr to set the IV pump to infuse magnesium sulfate 40g in 1000mL LR to
infuse at 1g/hr.
e. Calculate how many capsules of nifedipine (Procardia) will be needed to give the
sublingual dose. Supply: 10mg/capsule.
tablets = 1tablets/500mg × 250mg
= 250tablets/500
= 1/2tablets
ml = ml/20mg × 5mg/1
= 5ml/20
= 0.25ml
= 15000ml/30hr
= 500ml/hr
ml/hr = 1000ml/40g × 1g/hr
= 1000ml/40hr
= 25ml/hr

OBGYN
Dr MUSA MARENA
Unit of measure capsule
capsule = 1capsule/10mg × 10mg
= 10capsule/10
= 1capsule

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