I can't take it anymore. I have wracked my brain trying to figure out the math or even best practice on this issue. In desperation, I turn to you, o mighty nursing think tank!
Behold, the most baffling med math I've ever seen:
My homecare patient gets an uncommon drug in a weekly infusion. To keep me slightly more anonymous, and for ease of readability, we shall call it MiracleDrug . The order: Infuse 4 grams of MiracleDrug IV over 30 minutes every 7 days. My patient gets 4 vials shipped to his home every week for me to infuse.
Easy, right? Here's the problem. MiracleDrug is not a standard 1 gram per vial. Depending on the lot number, it can be 1100 mg or more per vial.
MiracleDrug comes with 4x20 mL vials of sterile water to reconstitute into. Per the drug insert, I use a transfer needle to put all of the diluent in the MiracleDrug. Simple, straightforward med math means that I draw up, say, 65 mL of reconstituted drug to make 4 grams.
The problem is that there is quite a bit of MiracleDrug powder in each vial, so when I reconstitute it, each vial contains probably 25-30 mL altogether. But unlike most meds, there isn't an insert to say "add 18.7 mL sterile water to equal 20 mL of reconstituted medication at a concentration of 58.4 mg/mL". Instead I'm adding 20 mL to equal an unknown volume.
So sometimes, when I've tried to do this properly, I end up drawing up all my required volume out of only 3 vials, leaving the 4th untouched! That means the patient would only be getting 3.3 g of MiracleDrug instead of 4 g.
Anyway, I've tried to escalate this issue every way I know how. I've emailed the MiracleDrug supervisor at my company. I've called the pharmacy for help. I've called the drug company for help. I've called the prescribing physician's office at least 4 times. If I could just get the physician to change the order to "4 vials q weekly", I'd be okay.
But alas, nothing. Either people don't know, or they don't care, or both. Obviously, I care a lot, because I want my patient to receive the proper dose and stay healthy, and because it's my ass on the line if he develops complications from being chronically over- or under-dosed.
Until this situation gets resolved somehow, I've decided to just give him the contents of all 4 vials, which can be up to ~4.6 grams altogether. I've charted everything so far including all the phone calls and emails I've sent about the issue. I get the feeling that there MUST be other colleagues giving this med without asking these questions. But now that I've uncovered the issue, I can't "unsee" it.
Nurses, can you help me? Perhaps you can point out something I'm missing in my med calc, or help me figure out how to gracefully handle this issue without losing my job or my licence.
Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.
What does the vial label say?
So if the vials are labeled as:
#1 995mg mystery drug sterile powder for reconstitution
#2 1005mg mystery drug sterile powder for reconstitution
#3 900mg mystery drug sterile powder for reconstitution
#4 1105 mg mystery drug sterile powder for reconsitution
with an variable of +/- 3%
you have 4 vials of 20mL each of sterile WFI
Add 20mL sterile WFI to each vial, then draw the volume up of each vial and use for infusion as 4005mg reconstituted mystery drug in 80mL WFI (volume may be 90mL or 100mL depending on the actual volume of the powder) this would be within the acceptable parameters to 4g of mystery drug within the acceptable variance of +/- 3%.
Is this an on-the-market medication? Do you have the manufacturer's drug insert? The manufacturer should have a written protocol for reconstitution and acceptable concentrations (such as 20mL added to vial of 1000mg drug +/- 3%). It is understandable if this is a specialized drug derived from a natural source that the concentration may vary by a significant amount but there is still an acceptable range (like natural Thyroid (Armour Thyroid) vs. synthetic levothyroxine) such as 1g +/-5%
Scale would be a very BAD idea as even in the pharmacy the scale must be an analytical balance that is calibrated and the procedure done under sterile conditions under a laminar flow hood. In addition it depends on the density of the powder, 4 grams of active drug does not necessarily weigh 4g it may way 6g or 10g...
I would get a 30ml syringe if you can find one and draw up all of the drug from the vial after the diluent is added to get a total volume. Then you will know it's 1.25 grams per 25ml or whatever and be able to figure out the needed volume.
Esme12, ASN, BSN, RN
20,908 Posts
Nice work...:)