Professor: Dr Mary Bennett
Answers with Demonstration for Practice Quiz 1 Just Give Me the Answers Note, two methods of obtaining the answer are demonstrated. I recommend the Dimensional Analysis method, because you can use the same "formula" to solve all the problems on your N205 math test. However, pick whichever one makes you happy. If you don't understand the Dimensional Analysis Method and want to learn how to do it, go to the math tutorial page for an explanation of how to do it before you look at the demo problems here.
1. 1/4 ounce = _________ cc.
Dimensional Analysis Method
Answer Units = cc
Conversion Factor = 30cc/oz
1/4oz30 cc
_____ X _______ = 7.5 cc
1ozOld Fashion Method There are 30 cc in one ounce.
Multiply the number of oz x 30 cc to obtain the correct answer.1/4oz x 30 cc = 7 . 5 cc
2. How many cc in 3.75 TBLS
Dimensional Analysis Method
Answer Units = cc
Conversion Factor = 15 cc/1 TBLS
3.75TBLS.15 cc
_______ X ______ = 56 cc
1TBLS.Old Fashion Method
There are 15 cc in one tablespoon.3 . 75 times 15 = 56 cc.
3. Ordered tylenol 600 mg. Have tylenol 250 mg in 1/2 tsp. How many cc will you give?
Dimensional Analysis Method
Answer Units = cc
Conversion Factors = 250 mg/ 1/2 tsp AND 5 cc/1 tsp600
mg1/2tsp5 cc
______ X _______ X ______ = 6 cc
250mg1tspOld Fashion Method
First convert the half teaspoon to cc
Then use the standard formula
(dose ordered/dose available x the number of cc).There are 5 cc in one teaspoon
5cc x 1/2 tsp = 2 . 5 cc.Now use the standard formula:
600 mg/250 mg x 2 . 5 cc = 6 cc.
4. Ordered ceclor 550 mg. Have ceclor 400mg in 5mL. How many ml will you give?
Dimensional Analysis Method
Answer Units = mL
Conversion Factor = 400 mg/ 5mL
550mg5 mL
______ X ________ = 6.875 mL (See Rounding below)
400mgOld Fashion Method
Just use the standard ordered/available x ml formula550/400 x 5 ml = 6 . 875 ml.
(See Rounding below)How do you give 6.875 cc? Mathematically, this number rounds to 6.9 ml. However, in the clinical setting, you would need to give this in a 10 ml syringe which has marks every 0.2 ml. You would therefore have to draw up either 6 . 8 ml or 7 ml. I would give 6 . 8 ml, rather than "round" 6.87 ml clear up to 7 ml, to avoid any possible overdose. If you have questions about this type of rounding, see the rounding page on this web site. - NOTE: I don't have any rounding of this sort on the quiz (just in clinical when you give meds).
5. Ordered tylenol 15 grains. Have tylenol 160 mg in 1.6 mL. How many ml of tylenol will you give?
Dimensional Analysis Method
Answer Units = mL
Conversion Factors = 160 mg/ 1.6 mL tsp AND
60 mg/1 gr
15gr60mg1.6 mL
_____X _____ X _______ = 9 mL
1gr160mgOld Fashion Method
First convert the 15 grains into mg. There are 60 mg in one grain, so 15 x 60 = 900 mg.Now use the standard formula. 900mg/160 mg x 1.6 mL = 9 mL.
6. Ordered 750 cc D5W with .45%N/S in 6 hours. How many cc/hr?
Dimensional Analysis Method
Answer Units = cc/hr
Conversion Factors = None
(you want to keep all the factors in this problem)
750cc
_____ = 125 cc/hr
6 hoursOld Fashion Method ( in this case, the two methods are the same)
750 cc / 6 hr = 125 cc/hr7. Ordered 1000 cc D5W with .45%NS in 12 hours. How fast should you run the IV in gtts/minute if you are using 15 gtt/ml tubing?
Dimensional Analysis Method
Answer Units = gtt/min
Conversion Factors = 60 minutes/hr AND 15 gtts/cc1000
cc1hour15 gtts
_____ X _____ X _____ = 20.8 or 21 gtts/min
12hours60 min 1cc
Old Fashion Method 1000cc/12 hours = 83.33 cc/hr .
To convert cc/hr into drops/minute; use the IV formula.
83.33cc/60min x 15gtt/mL = 20.8 or 21 gtt/min.
8. Ordered Demerol 80 mg and Vistaril 50 mg IM. You have Demerol in 1 ml ampules with 100 mg/mL. Vistaril is in a 10 mL multidose vial labeled 50 mg/mL. What is the total volume to be given?
First, why do I care about total volume?
These medications are ordered together to treat pain and nausea. They can be given mixed in the same syringe, to avoid giving the patient separate IM injections. In order to correctly draw up the two medications in one syringe, you need to know how many cc of each medication you will give, and the total volume you will end up with in the syringe.
Dimensional Analysis Method
Answer Units = mL
Conversion Factors = 100 mg/ 1 mL (Demerol) AND 50 mg/mL (Vistaril)
Demerol 80mg1 mL
_____________ X _____ = 0.8 mL
100mgVistaril 50
mg1 mL
___________ X _______ = 1 mL
50mg0.8 mL + 1 mL = 1.8 mL
Old Fashion Method (Ordered over Available) Demerol 80mg/100mg x 1mL = 0.8 mL
Vistaril 50 mg/50mg x 1 mL = 1mL
0.8mL + 1mL = 1.8 mL
9. If an IV is to run at 83 cc/hour, how many gtt/minute if you use 15gtt/ml tubing?
Dimensional Analysis Method
Answer Units = cc/hr
Conversion Factors = 15 gtt/mL and 60 minutes/hour
83cc1hour15 gtts
____ X _____ X _____ = 20.75 or 21 gtts/min
1hour60 min 1ccOld Fashion Method
This one uses the standard IV formulacc/minutes x gtt/ml = gtt/min.
So 83cc/60 minutes x 15 gtt/ml = 20.75 or 21 gtt/minute.10. At 1600 hours you started an IV with 500cc of D5W running at 40 gtt/min using microdrip (60 gtt/cc) tubing. You now receive an Abbott IV pump. How many cc/hr should you set the pump for to keep the IV going at the same rate?
Dimensional Analysis Method
Answer Units = cc/hr
Conversion Factor = 60 minutes/hour40
gtts60min1cc
______ X ________ X _______ = 40 cc/hour
1min1 hr 60gttsOld Fashion Method
This one is more complicated.
First step change gtt/min into cc/minute.
To do this, you need to know the gtt factor, which in this case is 60 gtt/cc. Then multiply cc/minute times 60 minutes to get cc/hr.40 gtt/minute
_________ = . 0.666 cc/minute
60 gtt/cc0.666 cc/min x 60 minutes in an hour = 40 cc/hr.
NOTE: For those of you who are observant, you might notice that the ultimate answer in cc/hr is the same as the original rate in gtt/minute (40 gtt/min ended up being 40 cc/hour). This will always be the case IF THE DROP FACTOR IS 60 GTT/MINUTE, because there are 60 minutes in an hour, so the two 60's cancel out. For example, if the IV is running at 30 gtt/minute and you are using 60 gtt/ml tubing, the IV rate in cc/hr is 30 cc/hr. This can save you time figuring out the answer, if you remember this trick. However, the trick does not work if the gtt factor is anything other than 60/minute, so you still have to be able to do this type of calculation.
11. What time will the infusion in question 10 be complete? ( You already have calculated that the IV is running at 75 cc/hour in the previous problem).
NOTE: 12.5 HOURS IS NOT 12 HOURS AND 50 MINUTES. Pay attention here. Students miss this type of question every year because they don't correctly convert parts of an hour into minutes. YOU HAVE TO MULTIPLY THE 0.5 PARTS OF AN HOUR X 60 MINUTES TO END UP WITH MINUTES.
Dimensional Analysis Method
Answer Units = time (hours and minutes)
Conversion Factors = 40 cc/hour (calculated in problem 10).500
cc1 hour
____ X ____ = 12.5 hour. (SEE NOTE BELOW)
40cc
Old Fashion Method
This problem requires you to use military time and some critical thinking skills. The IV is going at 40 cc/hr - we figured that out in question number 8. When you started the IV at 1600, you had 500 cc in the bag.
500cc/40 cc/hr = 12.5 hours. (SEE NOTE BELOW)
0 . 5 hours x 60 minutes in an hour = 30 minutes.So add 12 hours and 30 minutes to 1600 and you end up with 2830.
Now there are only 2400 hours in a day, so subtract 2400 from your 2830 and you end up with 0430. (Which is 4:30 am for those of you new to military time).
12. Ordered Penicillin 75,000 units. Have 10 ml vial labeled Penicillin 100,000 units/ 5 mL How many mL will you give?
NOTE: BE CAREFUL WITH MULTIDOSE VIALS. The label will state both how much is in the vial AND the dose concentration. YOU NEED TO KNOW THE DOSE CONCENTRATION. This problem states that the vial holds 10 ml of fluid, but the dose concentration is 100,000 units/ 5ml. This is the information you need to solve the problem. I gave you the other information in an attempt to simulate the clinical situation, where you have to read through all the information on the bottle, and decide which numbers you need.
Dimensional Analysis Method
Answer Units = mL
Conversion Factor = 100,000u/5 mL75,000
u5 mL
________ X ________ = 3.75 mL Round to 3.8 mL
100,000uOld Fashion Method 75,000 units/100,000 units x 5 ml = 3 . 75 cc.
However, the closest you can measure in a 5 cc syringe will be 3 . 7 and 3 . 8, so I would round up to 3.8 ml.
13. You have an IV running at 15 gtts/min using marcodrip (15gtt/ml) tubing. You are going to switch the infusion over to an Abbott pump. How many cc/hr will you set the pump at to keep the infusion running at the same rate?
Dimensional Analysis Method
Answer units = cc/hour.
Conversion factors = 60 minutes/hour and 15 gtt/cc15
gtts60min1 cc
______ X _____ X _____ = 60 cc/hour
1min1 hour 15gttsOld Fashion Method
This is the same type of problem as question number 10. The first step is to change gtt/min into cc/minute. To do this, you need to know the gtt factor, which in this case is 15 gtt/cc. Then you have to multiply cc/minute times 60 minutes to get cc/hr. The steps are outlined below.
15 gtt/minute
_________ = 1 cc/minute.
15 gtt/cc
1 cc/min x 60 minutes in an hour = 60 cc/hr.14. You are ready to give the 0900 dose of benadryl. The IVPB contains 30 cc of medication. The pharmacy instructions state that the medication is to run in over 45 minutes. The IV pump must be set in cc/hour. How many cc/hr must you set the pump for in order to run 30cc IVPB in 45 min?
Dimensional Analysis Method
Answer Units = cc/hour
Conversion Factor 60 minutes/hour30 cc 60
min
_____ X _____ = 40 cc/hr
45min1 hourOld Fashion Method
This one requires use of algebra and critical thinking.
30 cc ? cc
_________ = _______
45 minutes 60 minutes.Use algebra to solve for the unknown (?)
30 cc x 60 minutes
_______________ = 40 cc / hr.
45 minutes15. Order reads 75 ml of 10% Glucose to infuse at 65 gtt/min. Using 60 gtt/ml tubing, how long will it take the solution to infuse?
Why do I care what time it will be when the IV runs dry???
Dimensional Analysis Method
Answer Units = time (hours or minutes)
Conversion Factors: 60 gtt/mL and 60 minutes/hour75
mL60gtts1 min
_____ X _____ X _____ = 69 minutes.
1mL65gttsOld Fashion Method
This one is lots of fun (I would use Dimensional analysis if I were you).
First convert gtt/minute into cc/hour, so you can figure out how long the 75 ml will last.
To do this, you need to know the gtt factor, which in this case is 60gtt/cc. If you remember the trick from question number 10, you already have figured out that 65 gtt/minute is going to be 65 cc/hour. If you don't remember how to solve this problem, review the steps for question number 10.
Now that you know the IV is going at 65 cc/hr, how long will 75 cc last?
75cc/65cc hr = 1.15 hours THIS IS NOT 1 hour and 15 minutes. It is 1 hour and 9 minutes (0.15 hours x 60 minutes is 9 minutes).
If the IV runs dry before you are able to hang a replacement bag, the IV could clot off and you would have to stick the patient again to start another IV. To avoid this problem, know when your patient's IV will be getting low, check to be sure you have the right IV solution on hand before the IV runs dry, and call pharmacy for a new bag if you don't have one handy.
16. At the end of your 8 hour shift, you are calculating I&O for your patient. When you received report from the previous shift it was stated that this patient had 375 cc remaining in her IV for you to count. During your shift the patient ate one egg and a slice of toast for breakfast and had a hamburger, french fries and 4 oz. of tea for lunch. She also drank two cartons of milk at 8 oz. each and had 150cc of pop. The client then became nauseated and vomited 150 cc. She also starting having stomach cramps and passed two liquid stools. After vomiting, she has only eaten and retained one 90 cc orange popsickle. She voided clear yellow urine three times during your shift: 250 cc, 365 cc, and 200 cc. You hung a new 1000 cc bag of IV fluid which now has 650 cc in it. The patient also received Keflex 250 mg IVPB in 50 cc of N/S one time during your shift. What is this patient's I&O for your shift?
How to Calculate the Intake
Oral Intake - the patient drank 4 oz of tea (120 cc), two 8 oz cartons of milk (2 x 240 cc = 480 cc), 150 cc of pop, and ate one 90 cc popsickle. This is all of her total oral intake, which comes to 840 cc.
IV fluid - the patient had 375 cc up in her IV when you started this shift. Sometime during your shift all of that 375 cc went into the patient. You then hung a new bag with 1000 cc in it. As you are getting ready to do I&O for your shift you note that only 650 cc are remaining in that bag you hung.
This means that 1000 - 650 = 350 cc of IV fluid from that bag went into your patient during your shift, so you count 375 cc + 350 cc = 725 cc IV fluid in your intake. The remaining 650 cc in the bag is left for the next shift to count.
IVPB - (IV piggybacks or IV meds) Your patient had one 50 cc IVPB so add this 50 cc to the patient's intake.
Total Intake is the sum of her oral intake (840cc) added to her IV fluid (725 cc) plus her IV med (50 cc)
1615 cc total intakeHow to Calculate the Output
For output, you add up the amount of emesis (150 cc) plus the amount of urine (250cc + 365 cc+ 200 cc). If the patient had an N/G connected to suction, you would count the N/G drainage as output also.
Total Output is the sum of her emesis (150 cc) added to her urine (815cc) + an unknown amount in liquid stool
Total Output is recorded as
965+ cc
You should get lots of practice with this type of problem during your clinicals.
This page created and maintained by Mary Bennett DNSc, RN