Can someone please help me with this Dosage calculation problem?

[Laura77598]

Hi all,

I am trying to work on some dosage calculation problems to prepare for my Dosage Calculations class this fall. I have been doing pretty good, but I can't sem to figure out this problem. Could someone please help me set this problem up w/ D.A?

Thanks for all your help!

Laura

10.Your client was supposed to get 1 L of D5LR over 8 hours, starting at 1700. When you checked the bag at 1800, 300 mL had infused. To what rate will you adjust the pump in order to finish on time?

[RANCH GIRL]

Since you have 700 mL remaining to be infused and 7 hours' time to finish the infusion, work the problem like this:

700 mL/7 = 100 mL/hour to complete this on time.

[Daytonite, BSN, RN]

your client was supposed to get 1 l of d5lr over 8 hours, starting at 1700. when you checked the bag at 1800, 300 ml had infused. to what rate will you adjust the pump in order to finish on time?

when setting up da (dimensional analysis, or factor label) problems you still need to know your basic formula of "dose desired divided by dose on hand" because this is how your equation of fractions (ratios) comes about that you will perform the math on. your original dose desired was 1 liter to be given over 8 hours. however, within one hour 300 ml had been infused from the bag. that is going to require subtraction as well when you set up the problem.

this, by the way, is a practical problem that does happen in actual nursing practice. so, to do this problem you are going to need to understand how to work mathematics with fractions and the order of operations that you perform when you are working with strings of terms to multiply and subtract (in this particular case). you are looking to end up with an answer that has a fraction (or ratio) with the labels of ml/hour on the numerator and denominator, respectively.

first

, recognize a very common conversion that needs to be applied here:

1 liter = 1000 ml (or cc)

.

then, you can set up this problem using da

:

1 liiter/1

(dose desired as well as dose on hand)

x 1000 ml/1 liter

(conversion factor)

- 300 ml/1 hour

(amount already given)

=

700 ml/7 hours

(new dose desired as well as dose on hand). [remember the order of operations in math "

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arentheses,

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ubtraction - the multiplication of the equation is done first leaving you with the subtraction of two fractions that both have matching labels in the numerators and denominators]

finally

, you need to simplify the final answer you just obtained:

700 ml/7 hours

(dose desired as well as dose on hand)

to:

100 ml/1 hour

. this is the rate you will adjust the pump to in order to finish the iv bag on time. with most iv pumps you have to input the number of

ml

(milliliters) per hour. therefore, it is important that your final fraction have the number "1" in the denominator.