Help Please! I can't figure out this dosage problem

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For some reason I cannot figure out these two problems dealing with Units. I have emailed my instructors but haven't got a response yet so I would appreciate some help.

The first problem is 50units of insulin, 500mL of .9NS @20 ml/hour (the answer is supposed to be 2.0 units?)

The second is 25 units of reg insulin in 250 ml of NS is ordered at 1 unit per hour with hourly dose tittations to maintain FSBG Between 70-90 mg\dl

Specializes in Cardiac Critical Care.

The use of Units shouldn't trip you up, calculate it as if it were any other measure (e.g. mg).

sugarmagnolia is right :up:

The first problem's answer is 2 units/hour while the second one is 10 ml/hour. :nurse:

1. 500 ml x 20 ml/hr will give you 25 hours

50 units/ 25 hours = 2 units/hour

The same way goes for the second problem.

2. 25 units x 1 unit/hour will give you 25 hours

250 ml / 25 hours = 10 ml/hour

I hope you get it.

Specializes in Pediatrics, OB/GYN, ER, Geriatrics.
For some reason I cannot figure out these two problems dealing with Units. I have emailed my instructors but haven't got a response yet so I would appreciate some help.

The first problem is 50units of insulin, 500mL of .9NS @20 ml/hour (the answer is supposed to be 2.0 units?)

The second is 25 units of reg insulin in 250 ml of NS is ordered at 1 unit per hour with hourly dose tittations to maintain FSBG Between 70-90 mg\dl

1.) 50 units = 50mL

500mL/50 = 10mL

10mL/20mL= 2 units

Answer: 2 Units

2.) 25 units = 25 mL

250mL/25mL = 10mL

10mL/1mL= 10mL

Answer: 10 Units

HTH!

Christine, you make Calculations look sooo easy! I Dont have books yet, (Except A&P) so I'm teaching myself from web sites and it's alittle frustrating but exciting when I get an answer correct (math is not my strong subject!) I found "unit conversion" ie., mcg->mg->g->kg = •/• by 1,000 ..and X for the opposite.?? Does that look correct? I probably sound funny LOL.. but all this is so new to me and I want to learn asap! So thank you =}

Specializes in Cardiac Critical Care.

911brat, dosage calc problems are basically just ratio/proportion problems. Once you learn to set them up, they will come easily. You may want to pick up a book like Math For Nurses from Amazon, that'll come in handy in teaching yourself :) Our textbook for dosage calc was this one: http://www.amazon.com/Drug-Calculations-Problems-Clinical-Practice/dp/0323045766/ref=sr_1_1?ie=UTF8&qid=1317051508&sr=8-1 ...it would be helpful in learning how to set the problems up and has good info about administration as well.

Sugarmagnolia- Aww nice! thank you I will look it up and buy it today if there is one for fairly good price =} I can try to find out which book my program uses as well but I'm sure the more books the better! I hear there's 3 different ways to calculate/convert and finding the one that works easiest is best.

Thank you all soo much ur explanations helped soo much!!

Specializes in Pediatrics, OB/GYN, ER, Geriatrics.
Sugarmagnolia- Aww nice! thank you I will look it up and buy it today if there is one for fairly good price =} I can try to find out which book my program uses as well but I'm sure the more books the better! I hear there's 3 different ways to calculate/convert and finding the one that works easiest is best.

Gurinick uses Calculate With Confidence 5th Edition...this book is awesome and trust me when the program starts, you will have alot of time to learn the calculations stuff...you learn it in the prereq's and Module 1. I am not good at math either, but found what works for me and that is how I do it...the instructors always confused me so I had to tune them out and just do it my way...as long as I came up with the same answer, who cares how I do it right? lol...what campus are you going to again? I have no problem helping you when you guys get to this part in the class and show you the way I do my problems. Just PM me and I will give you my # so you can call me with any questions.

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