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.
The problem is once she's adding the fluid to the powder it's no longer 20ml, it's more like 25ml or some other variable amount. That's why I suggested a syringe to measure true volume in my first post. The change in volume can be significant if it's a large amount of powder.
The problem is once she's adding the fluid to the powder it's no longer 20ml, it's more like 25ml or some other variable amount. That's why I suggested a syringe to measure true volume in my first post. The change in volume can be significant if it's a large amount of powder.
I see what you mean. Then a scale would be the answer. Measure out 4 g of the powder and add it to 80 mL of water, measure the total volume when finished and infuse over 30 minutes.
You could still use the method I listed but you would need to measure the total volume of the bag in order to get the infusion time to exactly 30 min.
If each vial lists the correct amount of medication powder, then reconstitute the first 3 vials and add up the amount of medication listed on the labels of each, the final volume of fluid of the first 3 vials makes no difference at this point.
Figure out how much more medication you need to make 4 grams (if the first vials have 3300 mg then you need 700mg out of the 4th vial).
Reconstitute the 4th vial and measure the final volume. Using the concentration of the 4th vial (the listed dose of powder per ml of fluid in the final mix) draw 700 mg from the reconstituted 4th vial.
I see what you mean. Then a scale would be the answer. Measure out 4 g of the powder and add it to 80 mL of water, measure the total volume when finished and infuse over 30 minutes.
You could still use the method I listed but you would need to measure the total volume of the bag in order to get the infusion time to exactly 30 min.
Not possible. We're talking about reconstituting a sterile powder with sterile water while maintaining sterility. You cannot dump the contents out and just mix it up for IV infusion (unless you have a pharmacy hood under which to mix it).
I still think (having done this every week for 18 years), that everyone is over thinking this. The actual script should include the +/- percentage that is appropriate and it will no doubt include the minimal overage of medicine.
I am more confused than ever... It has to be that we are making this more difficult than it is??Hopefully at some point you can get the prescribers office to call you back.. Perhaps the prescriber does not realize how the medication is actually distributed? Best of luck!
After I wrote that I wondered if I was 100% correct about it. Do you know much (percentage-wise) it increases? Guess it might depend upon the quantity of powder.
I am with you, except, I believe the OP stated there is NO listing of med per volume....However, it would seem a simple thing to withdraw the total, observe the volume, and figure out the volume needed to obtain the needed dose...
If each vial lists the correct amount of medication powder, then reconstitute the first 3 vials and add up the amount of medication listed on the labels of each, the final volume of fluid of the first 3 vials makes no difference at this point.
Figure out how much more medication you need to make 4 grams (if the first vials have 3300 mg then you need 700mg out of the 4th vial).
Reconstitute the 4th vial and measure the final volume. Using the concentration of the 4th vial (the listed dose of powder per ml of fluid in the final mix) draw 700 mg from the reconstituted 4th vial.
Specializes in Complex pedi to LTC/SA & now a manager.
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...
Specializes in MPH Student Fall/14, Emergency, Research.
WOW I knew you guys would be able to help me out. That's why I love this website.
You make it sound like he's not getting the same drug dose delivered each week.
Right, it depends on the lot number. Each lot number has a different mg/vial. The order is for 4g/week.
What I have found is that the MD manufacturer will package the vials together for one dose. Those vials are unfailingly of the same assay amount, thus the dose comes down to how many vials of x assay = the proper dose.
Also of note: All reconstituted drugs hat I have ever dealt with carry a dosage which is +/- X%. That percentage usually covers quite a wide range of actual drug infused.
My guess from afar is that your MD manufacturer is packing together 4 vials with assays that constitute your patient's correct dose... But the +/- % differential may make a difference and simplify the whole equation.
This drug sounds very similar. I haven't noticed a +- assay. I will recheck the package insert next week!
Get a scale and measure out 4 grams and then reconstitute it.
No can do, it's in the sterile reconstitution vial.
The problem is once she's adding the fluid to the powder it's no longer 20ml, it's more like 25ml or some other variable amount. That's why I suggested a syringe to measure true volume in my first post. The change in volume can be significant if it's a large amount of powder.
Right. It's a lot of powder.
What's the big deal in saying what the real name of the medication is? The pt Mr. X is taking ____. That is pretty anonymous.
I appreciate the sentiment, and I normally agree with not being overly paranoid when posting, but it is a very uncommon medication and that information combined with my post history would point a big neon finger to me personally, and it would be pretty easy to figure out who my patient is. Especially if my manager were to be like "huh, I wonder what you do to mix this med" and googled it. This site is big and public.
If each vial lists the correct amount of medication powder, then reconstitute the first 3 vials and add up the amount of medication listed on the labels of each, the final volume of fluid of the first 3 vials makes no difference at this point.
Figure out how much more medication you need to make 4 grams (if the first vials have 3300 mg then you need 700mg out of the 4th vial).
Reconstitute the 4th vial and measure the final volume. Using the concentration of the 4th vial (the listed dose of powder per ml of fluid in the final mix) draw 700 mg from the reconstituted 4th vial.
This is EXACTLY what I'm going to do next week. Thank you!!!
Can you not get the Dr to change the order slightly?
I want him to. I keep leaving messages. He's a specialist so I can only reach him at his office number, and he doesn't keep office hours.
Perhaps the prescriber does not realize how the medication is actually distributed?
I'm 99.9% sure that the prescriber has no idea how the med comes, and if he knew how much trouble it's causing me, he would say "just give him the 4 vials!" and hang up on me. But it's not up to me, it's up to him, and until he says that I have to keep dealing with this.
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...
Each set of 4 vials have so far been with the same lot number and the same mg each. So last week they each had 1250 mg per vial. All together it was 5g. I will recheck the insert for the assay information, though I didn't see it last time.
flying, if you can't get him to return your call, do you know where he works? If it's right in town, ambush him. That way you might end all this stress - it's not fair for you to have to keep spinning.
blondy2061h, MSN, RN
1 Article; 4,094 Posts
The problem is once she's adding the fluid to the powder it's no longer 20ml, it's more like 25ml or some other variable amount. That's why I suggested a syringe to measure true volume in my first post. The change in volume can be significant if it's a large amount of powder.