IV Prep Question

Started by nkorth
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nkorth

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I'm working on IV calculations for practice, and I'm not sure how to calculate drip rate (gtt/min) for the following problem.

Gentamicin 1 mg/kg in 50 mL D5W IV over 20 min q8h.

Given:
Gentamicin 40 mg/mL in 2 mL vial
IV set delivering 10 gtt/mL
Weight 132 lbs

Thank you!
 
(50 mL/20 min)(10 gtt/mL)=25 gtt/min

Focus on the answer units and break down things into dimensional analysis. Think of the total picture as well - in 20 minutes, 50 mL will be drained. Hope that helps 🙂
 
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(50 mL/20 min)(10 gtt/mL)=25 gtt/min

Focus on the answer units and break down things into dimensional analysis. Think of the total picture as well - in 20 minutes, 50 mL will be drained. Hope that helps 🙂
Actually,

132 lb * 1 kg / 2.2 lb * 1 mg / kg * 1 mL / 40 mg = 1.5 mL Gentamycin has to be added, so...

(51.5 mL/20 min)(10 gtt/mL) is closer to 26 gtt/min
 
That's what I calculated, but the answer is stated as 17 gtt/min. Typo, maybe?
If the question said "over 30 minutes" that would be 16.667 gtt/min, so that's probably where the typo was. And if you account for the 1.5ml of gent, it's still 17.16, so answer will be 17 either way.