Nitroglycerin error

[Nightnurse95]

Hi, I was hoping for some feedback. I had a patient who has having chest pain so we started him on a tridil gtt. The initial starting dose said 10mcg/min and titrations by 10 until 200mcg/min. I accidentally set the pump at 10ml/hr instead. The patient felt relief but about an hour later was having chest pain again so I went to titrate it up but then realized The rate was entered wrong. The patient had a lot of blockages to begin with and was having a heart attack so I wonder if I made it worse. The rate was within the ordered range but the starting dose was higher than it was supposed to. I guess I was wondering what happens when you start it that high. When I fixed it the patient was still having chest pain and the PA said to keep increasing it and he ended up going for an emergency cath. I feel awful about it. I know it was a big mistake but I was just wondering what can happen to the patient and if maybe I caused the heart attack.  

[MunoRN, RN]

Dosage rate errors are not uncommon with Nitroglycerin due to the dose being very similar to the rate in ml/hr.  The dose and rate ideally should be obviously different measurements, or the same.  A slightly different concentration of what is typically available gives you a mcg/min rate that is the same as the ml/hr rate, which would solve this problem.

Luckily, the initial rate you incorrectly entered was not a potentially harmful dose, and is actually less that what we typically start chest pain patients at.  So long as their blood pressure held (and they aren't a right sided MI), then there was little likelihood of harm, of course that doesn't mean an error should be taken less seriously.

The one thing I would suggest is that sometimes when people recognize this error they change their current rate to mcg/min; you are at 20ml/hr then you see you've been using the ml/hr instead of the mcg/min and then you change the dose to 20mcg/min.  If the current rate has met the titration goals then leave the rate where it is, and chart what the dose is in mcg/min at that ml/hr rate.  

It sounds unlikely that you caused the MI, the patient came in with a likely MI which is why you started them on a Nitroglycerin drip.  For NSTEMIs it's not unusual practice to maintain them on a NTG drip so long as their CP can resolve on the drip, and heparin or other antiplatelet is often added as well.