Paramedic Math Shortcuts
After seeing some of those calculations I bet you are saying there has GOT to be a better way to figure some of this stuff out. You are right there are some easier ways…
I am not a practicing paramedic yet. In fact I’m barely a month into school at this point, so I’m positive there are more ways out there then the ones I know right now, I will add to this post as I learn new tricks and I welcome input from others who have a trick that works well.
Let’s start with the pounds to kilogram conversion – as we discussed 1 kg = 2.2 (or 0.453) lbs. To calculate that more quickly I divide the weight in pounds in half and subtract 10 ten percent.
For example 150 pound patient :
- 150/2 = 75 less ten percent 75-7.5 = 67.5 kg rounded up 68 kg – calculating this the proper way gives us 68.18 kg (divided by 2.2) or 67.95 (multiply by 0.453) so all three ways give us 68 kg
This is a quick and easy method most of you should be able to do in your head.
My favorite short cut is for dopamine drips. We were required to calculate how many mcg of dopamine in a single drop. So the concentration of the dopamine we carry once injected is 1600 mcg/ml. Using a 60 gtt set (60 gtt/ml) means that 60 drops equals 1600 mcg so 1 single drop contains 27 mcg (rounded up). So to calculate our drip rate we need to calculate the desired dose (dd) and then multiply that by 27.
For example Our order is to administer 5 mcg/kg/min we have a 400 mg vial of dopamine and a 250 ml bag (1600 mcg/1 ml) and we are using a 60 gtt set. The patient weigh 150 lbs.
68 kg X 5 mcg/min = 340 mcg/min divided by 27 = 12.59 gtt/min
Calculating it out the long way would give us : 12.75 gtt/min
Both of those would be rounded up to 13 gtt/min.
I will work on getting the clocks done for dopamine, lidocaine and epi in the next few days and add them as I get them finished.
I hope you found something useful in these pages or that they maybe demystified the drug math some for you.
Feel free to leave a comment and let me know how it worked out for you.