Diluting IV push meds

[Nurse24]

I’m a new grad working in acute care. When diluting IV push meds, I was told to use a prefilled 10ml NS syringe and to waste however many mls of the drug I needed. Ex, fentanyl is 100mcg/2ml so waste 2ml of NS to put into the syringe. My coworker then told me the concentration would be 10mcg/ml. Wouldn’t you need to put the med in 12ml of NS to make it 10mcg/ml? Probably overthinking this.

[Wuzzie]

I have a few questions.

1. Why are you diluting the Fentanyl?

2. Is using a saline flush syringe to dilute the medication acceptable practice?

3. How do you know that saline is the proper diluent?

4. If you put 2ml of Fentanyl 50mcg/ml in 8ml of saline (what you have left when you discard 2ml from a 10ml saline syringe) you end up with 100mcg/10ml. What is 100 divided by 10?

[_firefly, BSN, RN, EMT-B]

In general, I don’t think it is good practice to dilute meds and I’m curious about your reason. Consider that you should be flushing saline before and after the med and that the med will quickly reach the heart and be heavily diluted in blood, any additional dilution seems silly. Sometimes certain meds burn going in for certain patients, so that might be a reason. For example digoxin. Finally, consider that if the goal is to slow the delivery, the actual amount of saline doesn’t have to be precise at all. Just focus on how much of the med itself is to be given, waste what is extra, then dilute if needed. Do be careful in general that you are using a compatible diluent. 

[NicelySeasoned]

#1 What is your facility policy? If it doesn't support what your doing, you will wind up in trouble.

#2 ISMP says don't use prefilled saline flush to dilute anything.

https://www.ismp.org/resources/part-I-survey-results-show-unsafe-practices-persist-IV-push-medications