My friend and co-host at EMS Office Hours Dave Brenner has a great way to deal with dopamine drips in the field. Check out the method he wrote about below…..
…..I have often been asked how I know the drip rate for dopamine so quickly without a calculator. I’ll tell you. Feel free to share my method.
So here it is:
Rarely do we know a patient’s true weight. Even if they tell us, it may be way off or a little off (if they just ate a big meal, had a huge BM). Also, when you are dealing with gtts/minute, being off by one drip/minute is not meaningful. How would you set the drip to 37, or 111 gtts/minute in any meaningful way (unless you had an infusion pump)? The following method rarely results in more than being off by 1gtts/minute. And the patient doesn’t die because it took a half hour to do the math. Of course, there’s an app if you need it.
This works for 200mg Dopamine in 250ml solute (NS, D5, whatever) with 60 gtts/min administration set.
Take the patient’s weight in pounds and divide by six. Whatever the answer is, drop anything to the right of the decimal. Add one. That’s the drip rate for 5mcg/kg/min. Double that and you have 10mcg/kg/min. Double that and you have the rate for 20mcg/minute (the top end). Remember to titrate to the desired effect.
If you want to be dead-on accurate simply divide the patient’s weight in pounds by 5.86666667 – that will get you the precise drip rate for 5mcg/minute. Double that answer to get 10mcg/kg/minute. Double that and you have the rate for 20mcg/minute (the top end). Remember to titrate to the desired effect.
Try this with stupid numbers: patient weighs 187 pounds and you want 10mcg/kg/minute.
187/6 =31.1…. Now we drop the .1….. gives us 31. Add 1 and you have 32gtts/minute (for 5mcg/kg/minute). Double that for 10mcg/kg/minute 64/gtts/minute
Now the precise method: 187 / 5.86666667 = 31.8749999818892 double that you get 63.74999996377841. I say the answer above is close enough.
If you understand that we sometimes play with the start quantities – if you double the amount of dopamine you add to solute, you halve the drip rate – 400mg in 250ml. If you double the solute and leave the dopamine mg the same, you double the drip rate. 200mg in 500ml
Of course, if you double the dopamine AND double the solute you don’t have to do anything to the drip rates.
Thanks Dave for a nice fast tip.
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