Pediatric Dosage Calculation Problems

My fiance' and I were working pediatric dosage calc problems this weekend (we're such a happening couple are we not??? lol) and we cannot figure out how the instructor got the answer the following three problems - Can anyone help? Any assistance would be much appreciated

15 Order: Cefadyl 5 mg qid IM for a child weighing 44 lb.a. The drug book recommends 1-3 mg / kg/ day.

b. Is this order safe? ______to low___________

Why is this too low? Order is 5mg qid = 20mg per day

44lb = 20 kg x 1 = 20mg per day

44lb = 20 kg x 3 = 60mg per day

Seems nasty to give a little kid 4 IMs a day, but the dose is fine.

16. Order Ancef 200 mg IV q 4h for a child weighing 22 lbs.

a. The recommended dose is 80 – 160 mg / kg / day

b. Is the dose safe? __ yes _______

c. Ancef is provided as 1 g in 10 mL

d. How many mL would you draw up? ______ 2 mL ______

e. You are to add the Ancef to 10 mL of IV fluid and infuse over ½ hour.

f. How fast would you set the IVAC at? _________60 mL / hr _____

Why 60mL per hour?

Let's see here.

Child is 22lbs = 10kg.

Recommended dose is 80-160mg/kg/day

That would be a total of 800 - 1600 mg/day, divided into 6 doses (one dose q4h) would be

133 - 267mg dose, so 200mg dose is within range.

1gm/10 cc, so 200mg = 2cc

Your total volume would be 12cc (the 10cc + the 2cc). To give 12 cc in 1/2 hour, the rate has to be 24cc/hr. No idea why this says 60cc/hr. Makes no sense to me.

17. Order: Gentamicin 8 mg / kg /day q6h for a child weighing 72 lb.

a. Give ____65 mg/ dose ______ mg per dose.

b. Gentamicin is provided as 80 mg / 2 mL.

c. How many mL would you draw up/ ______1.62 or 1.6 mL _______

d. The Gentamicin is to be added to 15 mL of IV fluid and infused over 60 minutes.

e. How fast would you set the IVAC? _______35 mL per hour________________

why 35ml per hour?

This doesn't make sense either.

72/2.2= 32.7 (33) kg. Dose would therefore be 8 x 33 = 264mg/24h, in 4 doses = 66mg = 1.65cc.

Your total amount of fluid would be 1.65+15 = 17.5 (18) cc. To give that over 60 minutes, you'd set it at....18 cc/hr. Depending on how you do your rounding, I'm guessing the question intended to ask you to give it over 30 minutes, which would be 35cc/hr for a volume of 17.5cc. But you wouldn't give it that fast anyway.

Is your faculty trying to give you erroneous answers to practice checking somebody else's erroneous work?

THANK YOU THANK YOU THANK YOU - I'm glad to know we're not crazy... LOL Unfortunately this instructor is KNOWN for her errors - we did send her an email and of course... no response and the test is tomorrow... ha ha ha ha

THANK YOU THANK YOU THANK YOU - I'm glad to know we're not crazy... LOL Unfortunately this instructor is KNOWN for her errors - we did send her an email and of course... no response and the test is tomorrow... ha ha ha ha

Trying to be charitable here.... is she failing in other ways?

I'd take a printout to the head of the department and ask for clarification. If she is having other difficulties they may not be evident to students, but the faculty may be aware, and need this information.

And i forgot to thank you for knowing how to do basic algebra ... we see so many students here who don't.

Will do... Thank you really for taking the time to check it out...