Hurst Review 5th Day CD-ROM Math question

[jkm5017]

could anyone please tell me how the hurst review came up with 125mg/125ml for the final concentration in this problem. i understand the entire equation except for that part. i don't know how they get 125ml when adding to a 100ml bag.

please help, thanks.

to calculate does with infusion already in progress:

________mg/ml x _________ml/h = ______ mg/h

concentration pump setting dosage

example: calculate the iv infusion rate in ml/h for a 70 kg patient requiring dilitiazem, 5 mg/h. dilitiazem is in a single use vial with a concentration of 125mg/5 ml. it should be added to 100 ml d5w to make the final infusion solution.

calculation: dilitiazem 125 mg = 5mg + 100 ml d5w = 100 ml

final concentration: 125 mg/125ml = 1 mg/ml

answer: setting the infusion pump at 5 ml/h will result in a final infusion rate of 5 mg/h