Math calculation. Help!

Students Student Assist

Published

You are reading page 2 of Math calculation. Help!

sashaq

34 Posts

Ok, so far I have solved 18 of my 20 math calculation problems. These 2 are similar.

1. An IV infusion time is 13 hr 20 min. What is its completion time if it was started at 10:45 a.m.?

2. A 20gtt/mL set is used for a restart of 750ml of D5W at 3:03 p.m. at a rate of 32 gtt/min.

Infusion time_________Completion time_____________

I feel like I have done similar problems in the beginning of my program. But now that I'm going into my senior year we are redoing things that we have already been taught. Unfortunately, I seem to have forgotten how to do them.

For the second problem. I did this. 750 X 20gtt/1ml X 32gtt/1 min. I got 15000/32=468.75

I divided 468.75 by 60 minutes to get 7.8125. so 7 hours.

then I got the .81 from 7.8125 and multiplied by 60 minutes. so, .81 X 60= 48.6.

So, my answer was 7 hours and 49 minutes for infusion time. for completion time I just counted from the time started 3:03, which gave me 10:00. then i added my 48 minutes to the 3 minutes and got 51. so 10:51.

I'm sure there are simple steps to solving these problems.

bgxyrnf, MSN, RN

1,208 Posts

Specializes in Med-Tele; ED; ICU.

2. A 20gtt/mL set is used for a restart of 750ml of D5W at 3:03 p.m. at a rate of 32 gtt/min.

Infusion time_________Completion time_____________

You can come at this in two ways:

1) Think about the volumetric rate (mL/min) rather than the drip rate (gtt/min) and then determine how many minutes it will take to infuse 750mL.

2) Think about how many DROPS that you're going to infuse (that is, how many drops make up that 750mL bag) and then determine how many minutes is will take to infuse that many drops given the specified drip rate.

Either way, your infusion should take 7 hours and 49 minutes

Anonymous865

483 Posts

Ok, so far I have solved 18 of my 20 math calculation problems. These 2 are similar.

1. An IV infusion time is 13 hr 20 min. What is its completion time if it was started at 10:45 a.m.?

2. A 20gtt/mL set is used for a restart of 750ml of D5W at 3:03 p.m. at a rate of 32 gtt/min.

Infusion time_________ Completion time_____________

I feel like I have done similar problems in the beginning of my program. But now that I'm going into my senior year we are redoing things that we have already been taught. Unfortunately, I seem to have forgotten how to do them.

For the second problem. I did this. 750 X 20gtt/1ml X 32gtt/1 min. I got 15000/32=468.75

I divided 468.75 by 60 minutes to get 7.8125. so 7 hours.

then I got the .81 from 7.8125 and multiplied by 60 minutes. so, .81 X 60= 48.6.

So, my answer was 7 hours and 49 minutes for infusion time. for completion time I just counted from the time started 3:03, which gave me 10:00. then i added my 48 minutes to the 3 minutes and got 51. so 10:51.

I'm sure there are simple steps to solving these problems.

You got the correct answer, but the equation you wrote does not match the steps you took to get that answer.

You wrote

750mL x 20 gtt/mL x 32gtt/1min

You said that was 750 x 20 = 1500 gtt.

Then you divided by 32. Your equation indicated that you should multiply by 32.

In fact dividing by 32 was the correct step. The correct equation was

750mL x 20 gtt/mL x 1min/32gtt

Yay for you sashaq. You're doing a great job. Now you know you can figure it out in mg and then convert to mcg or what I do which is convert first. Both ways are correct and just reflect how our individual brains work. I'm very proud of you for sticking with it. Bring on the next problem.

Wuzzie, that was awesome. In your next life you should be an educator. Or a cheerleader.

+ Add a Comment