mixing meds?

tridil2000, MSN, RN · Mar 22, 2006

One of the old-timer CRNAs I work with routinely likes to mix Etomidate and Profofol 50/50 in the same syringe for induction or sedation for colonoscopies. I really like doing this as well, but got a lecture from one of the docs today about how I should never be mixing meds. One of the CRNAs I know even likes to put a little Ketamine in Propofol drips for sedation cases. What are your thoughts on this? I know studies have shown that you are not supposed to mix Lido and Propofol because lipid emboli can form, but everyone still does it anyway. Does anyone know of any studies involving Propofol/Etomidate mixtures?

nothing gets mixed with a diprovan drip in our unit. why not just push the etomidate on its own and after a flush use the diprovan. why take a chance when there's no reason to?

MmacFN · Mar 22, 2006

Im with you.

My understanding is nothing is mixed with lipid based meds like diprivan.

Is there any reason for this?

nothing gets mixed with a diprovan drip in our unit. why not just push the etomidate on its own and after a flush use the diprovan. why take a chance when there's no reason to?

Focker, CRNA · Mar 22, 2006

I have not had any clinical experience yet, but I am just starting to learn about these drugs. From a very novice point of view, I don't see why you would want to mix two sedative drugs like propofol and etomidate, when they are indicated for different reasons, but work via the same mechanism (GABA receptor). It seems to me you would be losing the benefits of both drugs and gaining the negatives. Like one of the main benefits of etomidate is that is has minimal cardiovascular effects, while propofol can bottom out your BP. Give both together and wouldn't you lose that CV stability of etomidate? Etomidate has side effects like myoclonic movements in up to 1/3 of pts. and adrenocortical suppression, if the pt. CV condition didn't necessitate etomidate, then why add it into propofol and invite these side effects?

EmeraldNYL, BSN, RN · Mar 22, 2006

Actually the reason this one CRNA likes to mix them is because you can lessen the disadvantages of both. If you use half the dose of Propofol, you minimize the CV depressant effects as well as the possible adrenocortical supression from Etomidate. In addition, this mixture seems to work really well for endo cases because Etomidate hangs around a little longer, therefore you don't have to bolus them every 2 seconds with Propofol to keep them adequately sedated.

MmacFN · Mar 22, 2006

ok a couple of questions then.

how does etomidate hang around exactly? i know it works fast, less than a minute and its effects can wear off as soon as 3-5 min (depending on the text you read). i assume you meant the 75 min half life? in anycase, it appears it could be considered contraversial to be using diprivan and etomidate togeather as research seems to suggest each can potentiate the others hypotensive effects.

one concern i see is how etomidate can block the adrenal gland's production of cortisol and other steroid hormones, possibly resulting in temporary adrenal gland failure. this could lead to abnormal salt and water balance, lowered blood pressure, and, ultimately, shock. the fact that this can last up to 8 hours is a serious consideration and studies seems to suggest that they remain unresponsive to adrenocorticotropic hormone (acth) tx for that time. depending on co-morbities, this is a serious issue.

when i think about diprivan and long term sedation im concerned about oppertunistic bacteria loving that emulsion base. secondly, the tissue uptake of the drug can be severe after a 5-0 day period slowing recovery for sure. as for use intitially, im not sure that etomidate would not be used but i dont think you would be wise to mix them in one syringe at all. secondly the doses would have to be carefully adjusted to account for the synergy between the two.

interesting stuff!

actually the reason this one crna likes to mix them is because you can lessen the disadvantages of both. if you use half the dose of propofol, you minimize the cv depressant effects as well as the possible adrenocortical supression from etomidate. in addition, this mixture seems to work really well for endo cases because etomidate hangs around a little longer, therefore you don't have to bolus them every 2 seconds with propofol to keep them adequately sedated.

heartICU · Mar 22, 2006

I have never mixed etomidate with anything, but we routinely mix either alfentanil or remifentanil in a 50cc syringe with propofol. The prop-alfenta mix works well for outpatient stuff, especially plastics. I have used the prop-remi mix for thyroids and parathyroids. If you want the little recipe I use, let me know.

Nitecap · Mar 22, 2006

The problem with mixing things like this is that the the syringe is prob going to look like a stick of propofol to any other person that walks up. If that person doesnt read to label that hopefully this guy puts he may dose it like it is only propofol and either harm or not adequatly treat the pt.

Now mixing say glycopyrolate and neostigmine I can see as long as you label it b/c giving the Neo b/f the glyco can be detrimental causing bradycardia and bronchospasm and severe issues. So It makes sense to mix these to actually thwart a potential adverse event.

If the practitioner wants to give both than fine but mixing them and leaving them hanging around can only increase the incidence of error. Especially is that CRNA is relieved by someone else and there is a syringe or bag full of this cocktail just hanging around.

Would also think that the mixture could increase infection incidence in the cocktail in the already infection prone propofol.

Either ways do whats best for the pt. I def. know that mixing agents like that is not standard of care and if just once you or someone else harmed a pt with the mixture whether by carelessness or someone not realizing they were giving both that some expert witness would testify saying the mixture expecially in a bag was inappropriate. Hey if you want to use both for an infusion why not just use a 2 channel pump and piggy back one into the other at least so you could know exactly how much you were giving of each at all times. As well just bolus them separately so you can know exactly how much you are giving each time for documentation. I would think since the propofol is lipid based that the etomidate would maybe settle toward one portion of the syringe and if you dont mix it b/f bolus one or the other may be coming out more at first. either ways why set yourself of someone else up for an adverse event when it is totally not needed to administer the drugs like that. My attendings freq tell me many times its the short cuts used to increase efficiency that can come around and bite you in the a$$ when you arent expecting it. Gotta play it safe sometimes in my book.

rn29306 · Mar 22, 2006

One of the CRNAs I know even likes to put a little Ketamine in Propofol drips for sedation cases.

OMG. White Lightning is awesome. 50mg Special K in 200 mg Prop.

Before you knock it, you might try it sometime.

EmeraldNYL, BSN, RN · Mar 22, 2006

Haha, that cracks me up, White Lightning? I never heard it called that before. :lol2:

Really, what is the difference between mixing Prop and Ketamine or Prop and Alfentanil vs. Prop and Etomidate?? Either way you are mixing meds.

And it's not like you just leave sticks of the stuff laying around, you draw it up for induction and use it, after properly labelling the syringe of course.

Mac, I know in the ICU they teach you that mixing ANYTHING is taboo, but anesthesia is a little different!

This topic really intrigues me and just proves that there are many ways to skin the cat in anesthesia. I think I'm gonna do a medline search, and if I find any good research articles, I'll let you know! If there's any experienced CRNAs out there who care to comment, please, join the conversation!

jwk · Mar 22, 2006

Haha, that cracks me up, White Lightning? I never heard it called that before.
Really, what is the difference between mixing Prop and Ketamine or Prop and Alfentanil vs. Prop and Etomidate?? Either way you are mixing meds.
And it's not like you just leave sticks of the stuff laying around, you draw it up for induction and use it, after properly labelling the syringe of course.
Mac, I know in the ICU they teach you that mixing ANYTHING is taboo, but anesthesia is a little different!
This topic really intrigues me and just proves that there are many ways to skin the cat in anesthesia. I think I'm gonna do a medline search, and if I find any good research articles, I'll let you know! If there's any experienced CRNAs out there who care to comment, please, join the conversation!

Granted we do LOTS of things different in anesthesia than the ICU or anywhere else. That being said, mixing other drugs with propofol just isn't a great idea. It increases the potential for contamination, especially if you prepare stuff ahead of time like many do. And do you get a good, homogeneous mix of drugs when one is in a lipid base and the other isn't? I don't know.

Also, mixing propofol and scheduled drugs like ketamine and fentanyl then raises issues about wasting controlled substances, which at least at my facility is a pain, and depending on the facility, may increase concerns about diversion of drugs. Doing what's easy and doing what's proper are sometimes two different things.

Pete495 · Mar 22, 2006

Sad to say when you push one drug after another, they all get mixed anyway.