Computation question please help

[Lorodz]

While doing practice questions for the NCLEX, I got confused on this one, can anyone enlighten me? thanks

A physician prescribes 1000 mL of 5% dextrose in water containing 1.5 mEq of KCl per 100 mL to infuse at a rate of 110 mL per hour.

At 7:00 am, the nurse hangs the solution

at 11:00 am, how much KCl has the client received?

thanks guys.

[FreeMilo]

the answer is 6.6

[*SS*]

Maybe this is the long way and is different from what others have suggested but,

Given: -1000ml of solution

-1.5mEq kcl per 100ml= 15mEq kcl total in 1000ml

Question wants to know how much kcl per 110ml so I asked myself how long would it take 1000ml to run at 110ml/hr. 1000ml/110=9.0909 hrs

Now take your total kcl of 15 which is in the 1000ml of solution and divide it by 9.0909hrs.

15/9.0909=1.6500017 this equals the amount of kcl in mEq that will run at 110ml/hr.

Now you can multiple that number by any time frame you want.

So...110ml/hr of solution with 1.65mEq kcl will deliver a total of 440ml with 6.6mEq kcl in 4hrs.

[student076]

this way might be a little easier for you to understand...

you are given that the bag is 1000ml containing 1.5ml per 100ml.

you are also given that the concentration is 1.5 ml kcl / 100ml this means that your total amount of the kcl in the bag is 15ml/1000ml (just multiply top and bottom by 10).

your rate is 110ml/hr.

from 7am to 11am you have 4 hours.

this means the total amount pumped at 11am is

4hr x 110ml/hr = 440ml

now take the part volume/total volume = part kcl/total kcl

this is 440ml/1000ml = xmeq/15meq

multiply both sides of the equal sign by 15

x = (15x440)/1000.

this works out to be x=6.6meq.

[Haseo007]

from 7am to 11am you have 4 hours...

4x110ml = 440ml

in order to get how much Kcl in 440ml..

1.5MEq : X___

100ml 440ml

X= 440ml(1.5MEq) / 100ml

X = 6.6MEq

[student076]

Dear Haseo007,

Yours is a great explanation - I could not figure out how to make fractions. What a great idea to underline!! Thank you!