NG Fluid Replacement Problen-math question help

Jolie, BSN · Aug 9, 2005

I was wondering if someone could please help me understand how to get this answer.
Question:
A child with a NG tube to low continuous suction has an order for 1L D5/0.225 NS @ 100cc/hr. The NG drainage is to be measured q.8h. and replaced with a second IV of D5W with 10 mEq KCl per 500 cc. The child's NG tube drians 380cc. What is the infusion time of the replacement IV?
the answer is 7 hours 36 minutes.... how do you get this answer?

What is the completion time of the replacement IV if replacement is started at 1500? answer in book is 2236.

I would appreciate any help. thanks.
PAPERQUEEN

Since the question does not specify a time over which the ng replacement should infuse, I would assume it is to be replaced over 8 hours.

380cc/8hr=47.5cc/hr

PAPERQUEEN · Aug 9, 2005

Since the question does not specify a time over which the ng replacement should infuse, I would assume it is to be replaced over 8 hours.
380cc/8hr=47.5cc/hr

the answer in the book is 7 hours 36 minutes for the infusion time... I am wondering what numbers you use to get to this answer. Thanks

Jolie, BSN · Aug 10, 2005

the answer in the book is 7 hours 36 minutes for the infusion time... I am wondering what numbers you use to get to this answer. Thanks

I don't know. The problem doesn't specify either an infusion rate or a time over which the infusion should be given. In the absence of such information, I would assume it is to be given over 8 hours, which is how it is done in the real world.

I'm afraid you have a poorly written question. I'd be curious to hear how your instructor explains it.

Daytonite, BSN, RN · Aug 18, 2005

I think I have your answer for you. If you convert 7 hours 36 minutes to all minutes you get 456 minutes. 380cc infused over 456 minutes is .83cc per minute or 49.9999 mL per hour. Therefore, I am assuming that the second IV of replacement fluid is going to be infused at 50cc/hr which is a nice round figure rather than 47cc/hr which would be the infusion rate for a straight 8 hours.

I think they did some rounding off to get to that answer. Is there some information that was given (like in the introduction section of problems) that would indicate that they wanted drip rates rounded to the nearest ten?

Normally, you would infuse the 380 cc over the period of time the drainage is collected which was 8 hours in this case.

nursefreak1 · Aug 19, 2005

I think I have your answer for you. If you convert 7 hours 36 minutes to all minutes you get 456 minutes. 380cc infused over 456 minutes is .83cc per minute or 49.9999 mL per hour. Therefore, I am assuming that the second IV of replacement fluid is going to be infused at 50cc/hr which is a nice round figure rather than 47cc/hr which would be the infusion rate for a straight 8 hours.
I think they did some rounding off to get to that answer. Is there some information that was given (like in the introduction section of problems) that would indicate that they wanted drip rates rounded to the nearest ten?
Normally, you would infuse the 380 cc over the period of time the drainage is collected which was 8 hours in this case.

I worked it out same as you and got the same thing with rounding.

I try to remember:

vol X calibration( dripfactor)/time and good old faithful want/have=give

good luck

hameedros · Apr 16, 2011

@PAPERQUEEN whats the name of the book?