# Dimensional Analysis Question

1. Hi all ~

We had our Nursing Care of the Child Rearing Family final today, and one of the questions was a cc/hr question.

Basically, it said " Pedi pt weighs 20 lb. Order is 1000ml/1st10kg/day. How many cc's per hour should the IV be running?"

Everyone in our class came up with either 38cc/hr or 42cc/hr - but no one is certain that they were right!

If you can give us the correct answer, we'd ALL appreciate it. (waiting for the instructor to inform us will take awhile)

Thanks! Now on to Psych rotation...
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3. Quote from SarahRN2B
Hi all ~

We had our Nursing Care of the Child Rearing Family final today, and one of the questions was a cc/hr question.

Basically, it said " Pedi pt weighs 20 lb. Order is 1000ml/1st10kg/day. How many cc's per hour should the IV be running?"

Everyone in our class came up with either 38cc/hr or 42cc/hr - but no one is certain that they were right!

If you can give us the correct answer, we'd ALL appreciate it. (waiting for the instructor to inform us will take awhile)

Thanks! Now on to Psych rotation...
I got 37.87cc/hr rounded 38cc/hr. We are not allowed to round but must truncate(sp) at the hundreds.
4. I don't use dimensional analysis, but working it out my way, I got 38cc/hr.

20lbs/2.2lbs per kg=9.1kg

9.1kg = 10kg
X 1000ml
Then you cross mulitply, and you get 910 ml. Divide that by 24 hours and you get 37.9 cc/hr or 38cc/hr

Hope that helps.
5. Good! That's what I got.

6. Using DA:

mL/hr = 1000 mL/10 kg x 1 kg/2.2 lbs x 20 lbs/24 hrs x 1 hr = 20000/528 = 37.87
Last edit by wonderbee on Mar 28, '05
7. Hang on guys ...

20 lb. = 9.09kg (relevant info is that pt. weighs < 10kg)

so: 1000ml/day = 1000/24 hours = 42ml per hour

8. Quote from MLOS
Hang on guys ...

20 lb. = 9.09kg (relevant info is that pt. weighs < 10kg)

so: 1000ml/day = 1000/24 hours = 42ml per hour

Yep, I stand corrected.
9. That makes perfect sense... but leads me to another question,

if the order is for 1000ml/1st 10kg/day - if the patient weighed more than 10kg - it would still be 42ml/hr? I've just never seen an order like this (not too surprising considering that we only had 5 weeks in Peds!)

Thanks for everyone's input on this!

Sarah
10. Quote from SarahRN2B
That makes perfect sense... but leads me to another question,

if the order is for 1000ml/1st 10kg/day - if the patient weighed more than 10kg - it would still be 42ml/hr? I've just never seen an order like this (not too surprising considering that we only had 5 weeks in Peds!)
In the "real world" this order would probably have been written in that format to comply with a facility's policy that all med orders be written as __mg/kg/day in an attempt to prevent errors in pediatric dosages. Especially when docs enter their own orders in an electronic system, there can be some strangely worded, choppy orders as various phrases are selected and "cut & pasted" together.

HTH