# pleaseeee help student nurse with peds math!

1. Hi everyone! Im hoping someone can help me...Ive been sitting here for hours and my mind is smoking!!! AHHHHH! Im doing my Peds rotation and I have to do a report on a patient and I cant figure out the math!!!!! Heres the info:

Pt is 33 months old. 36 inches, 31 lbs. (68 kg.)
One of the questions is askng to list the meds theyre taking and then calculate the patients safe dose range in 24 hours. The meds are:
Ampicillin 100 mg/kg/day 350 reg IV q6h <-- the 350 reg IV confused me but thats how it was written
Nysatin 100,000 u/ml to white plaque QID
How in the heck do I figure it out?

Calculate the pts 24 hour fluid needs, and hourly fluid needs. Include the rate if patient is receiving IV fluids. Heres what i got to so far:
10 x 100 = 1000
10 x 50= 500
48 x 20 = 960 The answers total 2460 ml/24 hours
Then I divided 2460 by 24 and got 102.5 ml/hour.

Am i correct in that part? But what do they mean by including the rate for the IV????
If anyone can help me I think Ill cry tears of joy!! I appreciate it sooooooooooooooooooooooooooooooooooooooooooooooooo
oooooooooooooooooooooooooooooooooooooooooooooooo much!

Thank you!!!!!!!!
Nicole

__________________
Nicole

Joined: Aug '02; Posts: 59
telemetry nurse

3. Originally posted by nicoleinphilly
Pt is 33 months old. 36 inches, 31 lbs. (68 kg.)
One of the questions is askng to list the meds theyre taking and then calculate the patients safe dose range in 24 hours. The meds are:
Ampicillin 100 mg/kg/day 350 reg IV q6h <-- the 350 reg IV confused me but thats how it was written
Nysatin 100,000 u/ml to white plaque QID
How in the heck do I figure it out?
The problem is in the weight calculations. 31 pounds is only 14 kilograms, not 68. 2.2 pounds = 1 kilogram.

So, divide 31 by 2.2 = 14.

So, the patient gets 100mg per kilogram a day.

100 x 14 = 1400

Now, that's in 4 divided doses (q6 hours)

1400 divided by 4 = 350mg per dose.

The nystatin isn't really dose. The 100,000 u/ml is just the strength. It's a topical cream, so it's kind of hard to actually dose it.

Hope that helps!

Heather
4. Originally posted by nicoleinphilly
Calculate the pts 24 hour fluid needs, and hourly fluid needs. Include the rate if patient is receiving IV fluids. Heres what i got to so far:
10 x 100 = 1000
10 x 50= 500
48 x 20 = 960 The answers total 2460 ml/24 hours
Then I divided 2460 by 24 and got 102.5 ml/hour.

Am i correct in that part? But what do they mean by including the rate for the IV????
Woot! I'm on a roll tonight!

I know nothing about peds, so I have no idea how you came up with the amount of fluid the child is supposed to get (I'm sure there's a formula you're using that I'm not familar with).

But I can tell you what they mean about the IV. Once you figure out what the child is supposed to have q24 hours, you have to subtract what you're automatically giving them in their IV (include piggybacks). The number that remain will be what they should be taking in orally.

So, using your numbers, if the child is supposed to be receiving 102.5 mL per hour, and an IV is running at 50 mL per hour (and I don't even know if this is appropriate for a child), then they should be getting the remaining 52.5 orally.

Heather
5. HEY! That was kinda fun!

(hope it helped!)

Heather
6. Originally posted by nicoleinphilly
Hi everyone! Im hoping someone can help me...Ive been sitting here for hours and my mind is smoking!!! AHHHHH! Im doing my Peds rotation and I have to do a report on a patient and I cant figure out the math!!!!! Heres the info:

Pt is 33 months old. 36 inches, 31 lbs. (68 kg.)
One of the questions is askng to list the meds theyre taking and then calculate the patients safe dose range in 24 hours. The meds are:
Ampicillin 100 mg/kg/day 350 reg IV q6h <-- the 350 reg IV confused me but thats how it was written
Nysatin 100,000 u/ml to white plaque QID
How in the heck do I figure it out?

Calculate the pts 24 hour fluid needs, and hourly fluid needs. Include the rate if patient is receiving IV fluids. Heres what i got to so far:
10 x 100 = 1000
10 x 50= 500
48 x 20 = 960 The answers total 2460 ml/24 hours
Then I divided 2460 by 24 and got 102.5 ml/hour.

Am i correct in that part? But what do they mean by including the rate for the IV????
If anyone can help me I think Ill cry tears of joy!! I appreciate it sooooooooooooooooooooooooooooooooooooooooooooooooo
oooooooooooooooooooooooooooooooooooooooooooooooo much!

Thank you!!!!!!!!
Nicole

__________________
Nicole

Heather is exactly right on the amp and wt conversion, except she went one step too far for your answer...1400mg is the 24h ordered dose. The nystatin COULD be the oral liquid, but you need more info to figure the dosage. Nystatin normally comes that way, so if that is the order, then you just give 1ml QID OR 24hr dose= 400,000u.

Now, what your instructor MAY want you to do on the above is look in your drug book and get the dosages from the book for a child this size and THEN calculate the safe dose by the recommended dosages. this is actually the "safe dose"..the above figures only give you the dose actually ordered.

Your fluid needs for a child that small looks mighty high to me. I'm not sure what the formula is for calculating fluid needs..there is one, but I know your # is mighty high for IVF's on a child that's NPO at the same wt.

I don't understand the figures you have on the ivf..explain?

I'm not sure the next question is referring to what heather says or if it's asking for a drip factor. Is there a way for you to know how much fluid you're going to use for your meds (did you get a dilution ratio?)?

tracy
Last edit by nurs4kids on Oct 21, '02
7. there is a formula for determining iv rates, Ijust cannot recall it at this time.
8. Great link for pharmocology that someone, and I can't remember who!, posted the other day. Here is the paediatric one, detailing IV fluids:

http://www.accd.edu/sac/nursing/math/peds3.html

So for a 14kg kid, it would need 1200ml TOTAL in fluids per day.
This equates to 50 mls/hour. As Heather explains, if the child is having no oral input, then your IV rate would be 50mls/hr. If taking oral fluids, then you would decrease IV rate accordingly.
I agree Heather, that was fun

PS I am assuming the web site information is OK.
Last edit by aus nurse on Oct 21, '02
9. You do have to go to the drug book for the safe dose range. Most peds drugs are a range, so you have to figure the low dose for therapeutic effect and the high dose for safe dose range. Figure both the 24 hour dose AND the maximum per dose; i.e. the max in 24 hours may be 500 mg but the safe per dose amount is 125 mg. Watch this, our instructors liked to trip us up. you have to know the minimum dose (therapeutic) and the maximum dose (safe dose) both are equally important. After you have figured you dosage range THEN check the dose ordered- is it safe and is it therapeutic. Remember, peds math is the same as adult math, math is math, in peds you have to figure the dose per kg which is an extra step but the safe dose and the therapeutic dose math is the same for peds or adults.
10. Hope it all looked better to you today nicole! Sometimes you look at something for so long you'll never see it correctly!

Good luck!

Heather
11. heres another maintenance iv rate formula for you

80cc /kg/per day divide by 24 to get hourly rate
12. Mark,
I couldn't remember the IV formula either...but your rate sounds much more realistic. As for the formula, it also is determined by the child's current hydration status. Many times, they will run them at 1.5 rate if dehydrated or having high output from drains/drainage.

Connie is exactly correct in reference to safe and therapeutic. I had an error above..that is NOT the 24h SAFE dose on the amp, it is the 24h ordered dosage.

ahh, guys..that wasn't fun..
fun is trying to figure out something like Unasyn dosage once the vial has been reconstituted..our rx has us spoiled on that one now..they just send up a sticker telling us how much h20 to add to the vial and how much to withdraw for the ordered dose.
13. WHEWWWWWWWWWWWW!!!!!! YOU GUYS ARE THE BESTTTTTTTT! I am now finished the report and there is no way in hell in could've been done without all your help! Thank you so much for really caring, you have no idea how much it means to me!

love,
Nicole
xoxoxoxoxox
14. The formula:

750ml x body area
-------------------------
24