Another med calc question

by semester1kid (New Member)

3,910 Visitors; 215 Posts

Here's something that showed up on a practice test. We were given the answer, which is 20 gtt and I did concoct a manner of figuring it out for myself. First I'll type out the question then my calculations of how I figured it out, then a couple of questions I still have (because even thought I figured something out, I'm still lost on this one)

*Give 800 units/hr of Heparin IV. Consider that 500L of D5W is available with 20,000 units of heparin added. The drop factor is 60gtt/min (***I don't think she meant to put 'min' after 60gtt???). Give (blank) gtt/min.

My calculation that worked to get 20 gtt/min was 800 units over 1 hour x 500 mL over 20,000 units. That gave me an answer of 20. Now for my question, I'm not clear as to why the 60gtt (micro drops) wasn't a factor in this calculation and I'm not sure if or how I could add 'gtt/min' to after the 20 when that type of unit was never in the equation. My thoughts are that I did it wrong but just happened to stumble onto a number that matches what she gave us as an answer....Thoughts???

Share on other sites

3,910 Visitors; 215 Posts

One thing I didn't consider is that 60 minutes in an hour and 60 gtt could cross each other out - is that my missing piece of the puzzle? Since they cross each other out, my answer would still be 20 and it would add 'gtt' and 'min' to the calculation

Share on other sites

Mandychelle79 has 2 years experience and works as a Psych Nurse.

9,147 Visitors; 771 Posts

500ML/20,000 *( 800 units /1 hr) * (1hr/60 min) *( 60 gtt/ml)

ml cross out, as do units and do hr and the 60's leaving you with gtt/min

Share on other sites

3,910 Visitors; 215 Posts

Thanks a lot - we have the actual test on Tuesday and wasn't certain how to handle that one, even though I had inadvertently come up with the right answer:)