Reconstitution Question

[Brauer]

Hello, throughout my RN schooling, we tackled many med problems, but now I'm in the field, I've encountered powdered, or re-constituted meds for the first time, and am somewhat confused with how to best approach these as I'm hearing different answers.

Although the packaging sometimes states what amount of diluent to add to create what concentration, I've noticed this info is not always present on the vial itself; so, would it then be incorrect to add whatever the appropriate fluid is (say, NS) as indicated, but use whatever volume of that fluid you want, provided you calculate for this when figuring out the concentration? For example, say what's ordered is 500mg of Ancef and I have available a 1 g vial of powdered Ancef, could I not simply add 10cc of NS to this and calculate my dose as 500mg/1000mg x 10mL = 5mL. In like fashion, if I choose to add say 5cc of NS instead, it would then result in 500mg/1000mg x 5mL = 2.5ml. Bascially, as long as things are kept proportionate, does it matter that you follow the *exact* amount of diluent to add according to the manufacturer, or is there some latitude here?

[canuckeh!]

Yes, it does matter what diluent and the amount that you add.

Some medications require specific diluents.

Also, if you add 10 mls of diluent to the powder in a vial you do not end up with 10 mls as per your calculations. Your volume is just a little bit more.That is why you will often see "add 5.8 mls of diluent".

If not having the package with the instructions is the real problem, I suggest that nursing address the problem with your pharmacy to ensure that directions are available with each dose.

[Brauer]

I understand what you're saying, and appreciate your correction. However, what's making this confusing is the following: Let's take Zosyn. I found one schedule posted on the wall at work that states to add 12.9cc diluent to a 3g vial of Zosyn to yield 200mg/ml. Now, if I go to my Davis Drug guide, it states to, "reconstitute with at least 5mL of sterile water for injection." Obviously the concentration is going to vary if I use either the stated minimum of at least 5mL or choose an even larger volume of diluent. Basically, how can one schedule be so specific as in the case of add 12.9cc on the poster at work, and the other (Davis) be so non-specific as long as a minimum of 5cc is used to determine the concentration?

[wonderbee, BSN, RN]

Do you use a computerized MAR? Our MAR gives instructions in small type with regard to administration of many drugs. A lot of people don't bother to read the instructions but I find they cut down on a lot of errors.

I guess if I were in your position, I'd talk with the unit director about the problem. Surely you aren't the only nurse having to reconcile reconstitution. In the interim, I'd call pharmacy every single time and let them figure it out.

[CarVsTree]

Basically, how can one schedule be so specific as in the case of add 12.9cc on the poster at work, and the other (Davis) be so non-specific as long as a minimum of 5cc is used to determine the concentration?

The difference is that Davis is a general guide. The poster at your facility is SPECIFIC to the policy in place at your hospital. I use Davis as a guide, but must use our hospital's policies on all drugs whenever I have a question, whether it is diluent concentration, Y-site compatibility, etc. When in doubt, call pharmacy and ask to speak with the pharmacist.

Also, many facilities (including the one I work at) are now have all meds pre-mixed in pharmacy. I think it might even be a JCAHO initiative. Perhaps your facility will eventually change to this. The only meds I dilute are injections, never infusions. The injectable will tell me on the bottle i.e add 4.5 ml for 5 ml 100mg/ml, drug...

Ancef, Zosyn, Flagyl, Cefepime all come up premixed.

[Brauer]

Ok, thanks for helping to demystify the discrepency between those two sources. I did call pharmacy today and the pharmacist I spoke with felt it was due to the Peds floor I work on having more specific criteria for diluent to be added. Yes, it would certainly be nice if pharmacy premixed the meds, but I'm certainly now more confident with the safety of my infusions and always have pharamacy available to call. Thanks!

[jonear2, RN]

If all else fails, call pharmacy. We actually have a pharm D on our floor every day (we are a teaching facility) who is there soley to answer our questions and god knows that i love that. But usually the only things we have to reconstitute are antibiotics and we have the mini-bags so its not really aproblem. Our facility is very aware that the more things the nurses have to mix etc are just more risk for error, so pharmacy prepackagesmost things for us. Its nice actually. Im all about safety.