Pediatric Med Calculation Questions

[Shaq23]

First of all, I am a new member to allnurses.com but have been viewing many post that have helped me out in my journey through nursing school. I am in my 4th semester and am having a rough time with pediatric medication calculations. I have two problems below that I can't figure out how to set up as to answer all four questions. I can calculate for the appropriate dose but can't understand how the rest of the problem comes together. Was wondering if anyone could assist?

1. Dr. order is Ampicillin 225mg IV every 4 hours. The pt weighs 16.6 kg. The recommended dose is 50-100 mg/kg/day. The guideline states 10 ml over 30 minutes. The pharmacy sends a vial with 250 mg Ampicillin in the vial. (Hint: after dilution you pull up 5cc of fluid).

A. Is this the appropriate dose for the pt?

B. How much will you prepare from the vial?

C. How much fluid will you have in the volume control device?

D. What rate will you set the pump for the medication and flush (flush is always 20 ml)?

2. Dr. Order is Gentamicin 78 mg IV every 8 hours. The pt weighs 26.4 kg. The recommended dose is 7-7.5 mg/kg/day. The guideline states 1mg/ml over 30 minutes. The pharmacy send a vial with 100mg/2ml.

A. Is this the appropriate dose for the pt?

B. How much will you prepare from the vial?

C. How much fluid will you have in the volume control device?

D. What rate will you set the pump for the medication and flush (flush is always 20 ml)?

Any help would be appreciated.

Thanks, Shaq23

[chare]

Rather than being provided the answer, it would be a better learning experience if you were to show us your work. This would allow us to better help you understand how to solve the problems.

The fact that these problems are for pediatric patients is a red herring. Other than the doses being weight based, the rest of the problems are solved the same as for an adult patient.

[Shaq23]

Thanks so much....let me show you what I have so far before I get stuck.

Dr. order is Ampicillin 225mg IV every 4 hours. The pt weighs 16.6 kg. The recommended dose is 50-100 mg/kg/day. The guideline states 10 ml over 30 minutes. The pharmacy sends a vial with 250 mg Ampicillin in the vial. (Hint: after dilution you pull up 5cc of fluid).

A. Is this the appropriate dose for the pt?

B. How much will you prepare from the vial?

C. How much fluid will you have in the volume control device?

D. What rate will you set the pump for the medication and flush (flush is always 20 ml)?

A. 16.6 kg x 50mg = 830 mg low end

16.6 kg x 100mg= 1660 mg high end

225 mg x 6 (doses in a 24 period)= 1350 mg This is in range, it's appropriate dose.

B. I don't understand the "guidelines" as to the "Hint"

Vial amt 250mg over X times 225mg over 5ml = 5.56 ml? This is as far as I can go and I can't figure out a formula for this type of problem. Hope this information or lack there of helps. Thanks so much.

Shaq23

[NotReady4PrimeTime, RN]

The "hint" suggests that the diluent volume is less than 5 mL but once added to the vial, combined with the contents of the vial the total volume will be 5 mL. 250 mg / 5 mL = 50 mg / 1 mL. With me so far? So now what volume of drug will you draw up to give you 225 mg? Then how much additional diluent will you need to give you the recommended volume/concentration according to your guideline? The rest of the problem is simple from there.