Math Calculation Help Please!!!!!

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Specializes in M/S Short Stay/TCU.

I took my med calc exam this monday and I got an 80. I need a 90% to pass. :crying2: I was wondering if someone could please show me how to do the following 2 problems. Are their any websites for problems like these two. I need practice on these types of problems, especially with setting them up and the formula. Please help, I have the math test again on Monday 7/7/08.:sniff:

#1. the nurse is administering 1,000ml LR IV over 8hours. drop factor : 20 gtt/cc. Calculate the rate in the IV infiltrated after 4hours has infused. Recalculate the rate in

ml/hr___________

gtts/min___________:no:

#2. an IV 750 ml D5.45NSS is infusing at a rate of 80 drops per min. the drip factor is 15gtt/ml. How long will it take for the IV to infuse?

how many hours___________ and minutes______________.:no:

Thank you

Specializes in crital care.

I'm no math whiz but for the first problem I came up with 41.6 gtt/min which you would round to 42 gtt/min, and the second part is 125 ml/hr.

The second problems I sort of struggled with but I gave it a shot and came up with 2.4 hrs. and 144 mins. Hope it's right let me know if I can help further.

Specializes in M/S Short Stay/TCU.

Hi Lilmzson,

I had the same answer that you got for the 1st problem and my Prof. said it was wrong because you have to recalculate the rate again. Thank you for your help.... I am stuck on the recalculating the rate part. also for #2. I wanted to know how to go about setting up and solving the problem.

Thank you for your help. I appreciate it!!!

Specializes in being a Credible Source.
#1. the nurse is administering 1,000ml LR IV over 8hours. drop factor : 20 gtt/cc. Calculate the rate in the IV infiltrated after 4hours has infused. Recalculate the rate in

ml/hr___________

gtts/min___________

Same answer as you two: 42 gtt/min and 125 mL/hr

Hi Lilmzson,

I had the same answer that you got for the 1st problem and my Prof. said it was wrong because you have to recalculate the rate again.

If the setup was not changed then the infusion rate at the first minute is the same as at the 4th hour is the same as at the end of the infusion. My question to the prof would be, "Recalculate it again after what?"

Calculate the rate in the IV infiltrated after 4hours has infused.
This sentence is nonsensical to me. Is that verbatim?

Either there's something missing in the problem statement or I'm very confused.

Specializes in being a Credible Source.
#2. an iv 750 ml d5.45nss is infusing at a rate of 80 drops per min. the drip factor is 15gtt/ml. how long will it take for the iv to infuse?

how many hours___________ and minutes______________.:no:

750 ml x (1 min / 80 gtt) x (15 gtt / 1 ml)

750 ml x (1 min / 80 gtt) x (15 gtt / 1 ml)

= 140.625 minutes

= 2 hours and 20.625 minutes ~ 2 hrs, 21 minutes

Specializes in med/surg, telemetry, IV therapy, mgmt.

the nurse is administering 1,000ml lr iv over 8hours. drop factor : 20 gtt/cc. calculate the rate in the iv infiltrated after 4hours has infused. recalculate the rate in

ml/hr___________

gtts/min___________

there is missing information here. to recalculate a rate you need to know how much of the 1,000 ml is left in the bag of iv fluid after x hours of infusion.

an iv 750 ml d5.45nss is infusing at a rate of 80 drops per min. the drip factor is 15gtt/ml. how long will it take for the iv to infuse?

how many hours___________ and minutes______________.

750 ml/1
(amount to infuse)
x 15 drops/ml
(drip factor of iv tubing)
x 1 minute/80 drops
(drip rate)
=
140.625 minutes
(length of time for iv to infuse)

140.625
divided by
60 minutes = 2.34375 hours

to convert the
0.34375
part of this number back into minutes, multiply it by 60 minutes to get
20.625
and round it up to
21 minutes.

the answer is
2 hours and 21 minutes
.

Specializes in M/S Short Stay/TCU.

Honestly, I wrote the entire problem out.I was literally going crazy from this problem.... I thank you all from the bottom of my heart for all your help!!!

You wont believe what the answer was to the first problem:

1000 - 400 = 600 ml which is left over, because 400 ml has already infused in 4hrs...

ml/hr = 600ml/4hr = 150ml/hr.

then you take : 150ml x 20gtt/ 60minutes which will give you 50gtt/min.

Thank you sooooooo much for your help!!!!!!

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