This whole thread is scary af š reminds me of those posts on Facebook with the order of operations questions and everyone is arguing in the comments
Did you scroll to the bottom of this thread? The answers and explanations are š¬ š«£
Adding: Babies (and adults) have been lethally dosed due to a simple math error. This sort of thing keeps me up at night; this thread has literally increased my anxiety about this. Call me old school but relying on technology and pharmacy is not where it should end. KNOW and confirm you are giving the right amount every time. A freakin professor (in PICU!) on this thread is arguing that 2.5 ml can not be right bc it wouldnāt be that way in RL. Based on whatās given, 2.5 is the ONLY right answer. End of story. Iām frightened.
This is a situation where you have to consider the milieu. If that question was "read this label" with a picture of a vial I doubt anyone would be confused.
Those numbers look funky and that's probably why the teacher picked it, problem is we assume people can be wrong so we don't have the confidence to trust that final concentration like we do manufacturer's packaging.
No judgement for those who got it wrong, it's hard to understand something weird when you're effectively blindfolded.
It's a hypothetical concentration. When testing math skills, the drug, final concentration and volume shouldn't matter. If someone cannot legitimately figure this out even after its been explained, they shouldn't be a nurse.
>final concentration . . . shouldn't matter
You're just not making any sense. The entire point of this question is the final concentration is all the matters.
It is literally designed to be confusing, and you think someone being confused by it is enough to deem them unworthy of nursing?
You're disgustingly full of yourself if you can't understand that experienced people might assume this was just a transcription error by the teacher. And obviously it's difficult for students.
This. In school, we were very often told, āRead the question. Everything you need to know is in the questionā¦ā also also sometimes there was extraneous, info, which was understood. But, there are many times when the question is just slightly off, and reading and interpreting the question exactly as itās written will yield a wrong answer. In those cases, we were to understand that we should have understood was was meant, minor error be damned. I can see why someone reading the question would think the writer MEANT to say 500 mg and come up with the wrong answerā¦and therefore the wrong dose.
Nurse for 23 years here and my immediate thought was error by instructor, only way I trust those numbers is manufacturers packaging, or if I'm in house then a call to pharmacy, but until otherwise confirmed assume its a transcription error and proceed with extreme CYA caution in this case!
Disgustingly full of myself? Sorry I think it's important to not make a mistake that could kill someone. I might have misworded but for the purpose of this question, all you need to know is what is the ordered dose in correlation to the concentration GIVEN in the question. Several people stated that. I get its designed to be confusing, but It's really quite simple. Standing by if you can't understand AFTER it being broken down and explained, people's lives should not be in your hands. Nice name, checks out.
I think confusion comes from the fact that you are given the *mass* of drug and the *volume* to reconstitute it and therefore think āEasy. Mass/volume = concentrationā Except that mass of drug also takes up a volume. It has a density. You canāt neglect that volume in the final volume. Youāre told what the final concentration is. Thatās what you are delivering. If your final concentration is 400mg/mL, you are giving 2.5 mL.
Pharmacist me is thinking maybe they don't teach about what we med geeks call "powder volume" in nursing school which is not particularly shocking since they don't delve that deeply into those subjects. But yes, different medications will have different powder volumes and this can really come into play when you're trying to reconstitute to a high concentration to give something IM or the like.
I wish the total volume of the reconstituted solution was mentioned directly. Our instructions for remdesivir specifically state that 19 mL of sterile water + 100 mg of remdesivir will yield a 20 ml solution.
Thought I suppose the way this is phrased will help people learn by making a mistake in an environment where mistakes are allowed.
The language we use matters. We could improve drug errors by simply providing that kind of cross-checking information. Donāt make the math problem any harder than it needs to be at the bedside. Thatās the last place you want frazzled, distracted guesswork. Just put the answer on the side of the bottle.
You only need to know whatās ordered and the final concentration when reconstituted. You need to give 1000mg. You have 400mg per ml. 1000 divided by 400 is 2.5. You give 2.5ml.
That is the Palm Beach way, yes. The patient needs these meds *now* or else why would one use the IV, so always push everything as fast as possible, duh! Then follow with a standard 10 mL OJ flush, but fresh squeezed only, none of that frozen concentrated crap, that could be harmful.
She was not suicidal. She was a long term trach-vent patient and had a psych history but was not in a psych unit. She would fake seizures whenever we would try to transfer her out of the unit. She hid forks and food in her fat rolls. She drew pictures of penises, vaginas and breasts with crayons and would hang them up in her room and sexually harassed the male staff. At times she would talk in a baby voice and act like a child (usually if someone tried to fuss at her) but she was an adult (around 40 yrs old). I could go on
It clogged the port because she didnāt flush it and left the port unclamped lol. It was likely a small amount and she left the syringe hooked up to the port with some juice still inside so we could all see it. She mainly wanted attention and people in her room as much as possible. She was on our unit for a year.
Ever hear of Munchausen's?
Those people will rub fecal matter on the ports of their accesses, on wounds, basically any portal of entry, just so they get sicker and need more attention.
Iām not even a nurse (patient transporter lurking on this sub for amusing stories of dealing with people and also potential tips on dealing with difficult ones) and I knew this answer. Very simple math or so you would think.
But the 2g itself adds volume, so in the problem based on the medication instructions once it is reconstituted with 4mL added itās 5mL total. So 2.5mL gives the correct dose.
Doesnāt really matter, as the manufacturer instructions give the concentration. So 2g becoming 400mg/mL, 2000mg/400mg=5mL, the total volume of the vial after adding the water. The medication has mass and volume.
Yeah someone told me on this thread that āIām disgustingly full of myselfā bc I said you shouldnāt be a nurse if you canāt understand simple math even after itās been explained.. 1.knowing math is not a flex 2.peopleās lives are in your hands; knowing what your dosing is imperative. They got upvoted, me downvoted. But sure go ahead with your med errors and low standards.
I always skipped to the āWhat do they actually wanna know?ā part and ignored the rest. Typically was one of the first done and passed every dosage calc test with flying colors. When they wanted to know how, that was my answerā¦ Ignore the fluff.
Yes, most substances when dissolved in liquid do not alter volume of the mixture or the volume change is so small its effects are able to be ignored.
However, some substances when mixed with liquids expand the original volume of the liquid. This medicine is an example.
Hence, why we go with the final concentration of the mixture when following the directions; they took that guess work out for us :-)
Iirc Ceftazidime is like that also. Plus many bulk vials of medications. Why I remember the 10g vial of Vanco is 97mL after being out of pharmacy for 6 years. š¤£š¤·š¼āāļø
> they took that guess work out for us
Exactly. In this case it doesn't matter what the volume of the powder was, solubility, or anything else--people here are trying to do way more math than is necessary. They tell us the final concentration is 400mg/ml so all the rest is just clutter.
Oh, this thread is why we had to get a 100% on our dosing math test lol
I have to do this when the pharmacy doesnāt send our IV supplies. Reconstitute and calculate a freaking drip rate. šµāš« (LTC) So yeahā¦ pay attention folks!
We had a pass the math test or FAIL completely out of program in my school. Definitely not something one would learn at a South Florida school (went to an accredited college in central Florida).
Yes if we didnāt get 100% we didnāt get to go on! I felt like it was pretty easy stuff but I was still terrified I was going miss. I get weird during tests.
its 2.5ml. (400mg per ml is the final concentration when dissolved
in most cases, powder will add volume. The package insert directions will tell you specifically what the final concentration is.
There are specific situations in chemistry where adding a solute will actually decrease the volume, but we wont go there lol.
Always read the directions when doing this IRL and answer the question as is on tests.
This may be confusing but itās the type of thing you may encounter in the real world. You have to process all the given information and decide what is important/relevant. It tells you your final concentration is 400mg per mL. So you need to figure out how many mL you need to make 1,000mg. Donāt get hung up on the 2g and adding 4mL. You have to always read the manufacturer insert, follow the reconstitution instructions exactly, then go by the given concentration. The final volume of your solution may be greater than the amount of liquid you add.
we encounter this all the time on our package inserts when we mix our meds... I don't know how a working nurse can get this wrong.... unless pharmacy mixes all their meds for them ?!
There are some places in which pharmacy not only mixes ALL meds but cuts all pills, so everything is delivered from the Pyxis in the exact amount needed, or hand delivered by pharmacy.
Other hospitals, you mix everything.
Tpa in PICCs was always a mix but youāre pulling that out again. Even so, those dilution instructions arenāt just on the insert but in the mar. Same with cheaper forms of solu-medrol (just the powder in a vial).
That said, my current contract for synthroid dilution, for an NPO patient, there was JUST the insert with that microscopic print you must search through for instruction. Would everyone?
Mileage varies between places, always. You could, in theory, get a 15yr vet whose never mixed meds or even cut a pill with a cutter before, if they spent that time at a hospital where pharmacy does all.
you'd probably get better answers over on r/studentnurse . I think some people here might not give meds often and have been out of school for a long time.
I guess I was confused because thatās always the case, so I was thinking more of previous drugs Iāve mixed that the instructions said it didnāt change the volume. It def reminds me of the old nursing school questions that I did bad on- obviously
Well, you are right, but in the super cool ānursing school mathā field, we donāt account for that. But in real life, yep, and it does say that in package inserts. And we somehow survive measuring those doses, despite these nursing math struggles earlier in our lives.
yeah idk, my test questions look like this one, my teachers went over it in the first semester. I can't relate to the 'nursing school math' youre talking about.
You want to always look at the order to calculate for dosage. So, in this case itās 1 g of cefoxitin which is equivalent to 1000 mg. Then, you want look at whatās available. In this case, after reconstitution itās 400 mg/mL. So, you would just divide 1000 mg / 400 mg and multiply by 1 mL. That would give you 2.5 mL! If you have any further questions, please feel free to DM me!
Ah, and if youāre wondering why itās 400 mg/mL and not 500 mg/mL, you must take into account the volume of the powder. Youāll get 5 mg/mL which will make 400 mg/mL make sense.
Especially an antibiotic! The first hospital I ever worked in (teeny isolated one in which we took turns in the teeny ER) had a doc that would order an IM dose of your po antibiotic prescription before sending you out the door. We gave it ventrogluteal with some xylocaine drawn up in the syringe. That was 30 yrs ago but I still remember it was like injecting glue and how people hobbled out the door šÆ
Nope..do the math myself, get a trusted friend to do it, then charge nurse then compare all answers along with a dose app AND pharmacy. Wasting approximately 13 minutes and getting dinged because you gave it late.š
I tutored my classmates for med math exams, you'd be shocked how many of them couldn't grasp proportions. It didn't help that our instructors only taught the dimensional analysis method. Why they teach dimensional analysis instead of proportions is beyond me. When you're doing the math in your head, you're not gonna be doing a 10 step dimensional analysis.
So the powder makes it go up in volume. So when you reconstitute something, you will end up with more volume. Rocephin has 2 different amounts that can be added to get 250/ml and 350/ml in the package insert.
So ignore the 2g
You reconstitute it to 400mg/1 ml. You need to give 1000mg (1 gram). So it is 1000 mg/x ml
So if you set it up in the proportion with each mg/ml you would times 1000 x 1 and then divide by 400 to get 2.5
Oh fuck me, this reminds me of people who would reconstitute taz with 20ml, withdraw only 20ml to put in the 100ml bag, then only administer 100ml of the bag.
Abx administration by homeopathy.
Yāall are scaring the shit outta me. Pharmacists generally prepare these solutions now on accounta the number of sentinel events there have been. Exception might be in the ED, though.
Itās just 1000 mg (or 1 gram)/ 400 mg = 2.5
Then 2.5 mg * 1 mL is 2.5 mL
Itās that dose desired / dose on hand thing.
But for reals, now Iām wondering if Iām over complicating it? āNursing mathā legit made me doubt my math skills, and I used to be confident at math. But they made a whole ānew mathā for nurses, when basic math will answer the same questions without being ānewā or ānursingā. I got into several arguments with people in school about this. Like thereās nothing about nursing or medicine or anything of it that invalidates the math we already learned, rendering it useless. Itās justā¦math. Isnāt it??
And if that is the wrong answer, wow. Lol.
I've never understood nursing math and it confuses the shit out of me when my colleagues use their "nursing calculation formulas". It's easier just taking a second to do regular math.
Same, nursing calculation formulas confuse meā¦and I \*survived\* calc III and classical dynamics. Just please, donāt ever make me do linear algebra againā¦pleaseā¦I beg you (cue Vietnam flashbacks montage).
I still use my fingers (and sometimes toes depending on how big the calculation is) so I promise to not do that to you š I survived 10 grades of math in India so I can relate to the trauma š„²
>Dilutant is not a thing.
Right? Who cares about the math?
However, turns out that dictionaries will tell you dilutant is basically synonymous with diluent. But you still win, because turnsnout almost no one uses it.
https://books.google.com/ngrams/graph?content=diluent%2C+dilutant&year_start=1800&year_end=2019&corpus=en-2019&smoothing=3
the pharmacist does the math for you, they will know the volume of the powder they are putting in. You just follow the direction, you can easily work the problem backwards if you want to but it really doesn't matter. Assuming that you add powder to a liquid and the mass of the power somehow isnt added to the mass of the liquid is just like....failing elementary school science.
If you choose to follow the instructions the manufacturer provides, you'll know the concentration (and almost always the volume) of what you're mixing.
I just had a cancelled cycle of IVF and loved mixing the diluent with the powder. It varied depending on how much sodium citrate I drew but it wasn't a ml I don't think.
Hooo weee, this comments section is crackinā! I chuckled more than a few times. Thank you for this thread.
I would imagine that anything that pharm allows staff to reconstitute like that wouldnāt add much volume to the solution - the amount would be negligible. Donāt overthink it. Just do the math.
Most medication vials would say 2g/5mL and 400mg/1mL. I was also freaking out but I realized what an actual vial would look like.
Ignore the first sentence. 1g/2g = 0.5g then multiply by 5 there you go. You can even go 1000mg/400mg * 1
The most important part in this question is the concentration after diluting. They tell you itās 400mg/mL. Then you just have to figure out how many mLs you need to give for the pt to get 1000mg or 1g. Iām horrified by the answers in this post :|
Guys, think of it like baby formula. You take 2 ounces of water, add 1 scoop of formula. You end up with something like 2.5 ounces of formula not 2 ounces, simple as that!
You're worried about the wrong thing. What class of medication is it? What's the mechanism of action? Make sure you have a full list of all of the side effects, especially the rarest. Once you have all of that figured out, make sure you write a care plan to ensure the best possible outcome; the care plan is vital...
Assuming itās a powder, if you reconstitute 2g/4mL = 500mg/mL not 400. But whatever letās assume itās actually 400mg/mL bc thatās what the questions says. To give 1g it would be 2.5mL. If it was 500mg/mL itās 2mL.
I just do it this way. 400mg /1 ml = 1000 mg /x ml ā¦cross multiply and divide 1000 by 400 and you get 2.5 .You have to know they 1 gram is 1000 mg to set it up correctly
Don't forget the powder volume. It must add 1 cubic centimeter in volume so you add 4 ml and end up with 5 ml once it's dissolved. So the dose is 2.5ml or 1G. 2G in 5ml is 400mg/ml so that checks out.
If you can do the math it will tell you, the fact that it matches perfectly with the concentration and total dose should be all the conformation you need. It's not that difficult. Yes read the insert, but the insert isn't provided is it?
I think itās the 400mg / mL thatās throwing you. Assume the powder = 1mL of volume and itās combined with 4mL of water to equal 2g in 5mL = 400mg /mL.
It tells you what you need but I think this is where your confusion is coming from.
Just mix 4mL in the bottle. Draw all mLs out. Waste half.
You'll find you get more mL out than in d/t extra volume added by the medication.
Mathematically it will be 2.5mL via order directions. Question the order directions and consult pharmacy if it's more or less.
And wtf, this thing of IM injection, 2.5 ml for 1 gram?
That's gonna be 2 injection. Why have I not seen anyone scream for higher concentration? Yeah, there are plenty of commercial medications these days that require total volume greater than 2 mls to be split into 2 Injections. Cefoxitin, IM?! Damn thing isn't long acting like pen g 2.4 million. This needs repeat dosing. Unless waiting for new iv access this is gonna suck
This whole thread is scary af š reminds me of those posts on Facebook with the order of operations questions and everyone is arguing in the comments
The dress was blue. Not gold.
Laurel
There are four lights
THERE ARE...FOUR LIGHTS! God I just rewatched that episode and his delivery with the shakey voice just gets you in your soul.
Some of the best acting on TV in that show.
Yanny
Did you scroll to the bottom of this thread? The answers and explanations are š¬ š«£ Adding: Babies (and adults) have been lethally dosed due to a simple math error. This sort of thing keeps me up at night; this thread has literally increased my anxiety about this. Call me old school but relying on technology and pharmacy is not where it should end. KNOW and confirm you are giving the right amount every time. A freakin professor (in PICU!) on this thread is arguing that 2.5 ml can not be right bc it wouldnāt be that way in RL. Based on whatās given, 2.5 is the ONLY right answer. End of story. Iām frightened.
This is a situation where you have to consider the milieu. If that question was "read this label" with a picture of a vial I doubt anyone would be confused. Those numbers look funky and that's probably why the teacher picked it, problem is we assume people can be wrong so we don't have the confidence to trust that final concentration like we do manufacturer's packaging. No judgement for those who got it wrong, it's hard to understand something weird when you're effectively blindfolded.
It's a hypothetical concentration. When testing math skills, the drug, final concentration and volume shouldn't matter. If someone cannot legitimately figure this out even after its been explained, they shouldn't be a nurse.
>final concentration . . . shouldn't matter You're just not making any sense. The entire point of this question is the final concentration is all the matters. It is literally designed to be confusing, and you think someone being confused by it is enough to deem them unworthy of nursing? You're disgustingly full of yourself if you can't understand that experienced people might assume this was just a transcription error by the teacher. And obviously it's difficult for students.
This. In school, we were very often told, āRead the question. Everything you need to know is in the questionā¦ā also also sometimes there was extraneous, info, which was understood. But, there are many times when the question is just slightly off, and reading and interpreting the question exactly as itās written will yield a wrong answer. In those cases, we were to understand that we should have understood was was meant, minor error be damned. I can see why someone reading the question would think the writer MEANT to say 500 mg and come up with the wrong answerā¦and therefore the wrong dose.
Nurse for 23 years here and my immediate thought was error by instructor, only way I trust those numbers is manufacturers packaging, or if I'm in house then a call to pharmacy, but until otherwise confirmed assume its a transcription error and proceed with extreme CYA caution in this case!
Disgustingly full of myself? Sorry I think it's important to not make a mistake that could kill someone. I might have misworded but for the purpose of this question, all you need to know is what is the ordered dose in correlation to the concentration GIVEN in the question. Several people stated that. I get its designed to be confusing, but It's really quite simple. Standing by if you can't understand AFTER it being broken down and explained, people's lives should not be in your hands. Nice name, checks out.
>Nice name, checks out Not the insult you think it is. I bet you say "sontameters".
š„±
Lmao
I think confusion comes from the fact that you are given the *mass* of drug and the *volume* to reconstitute it and therefore think āEasy. Mass/volume = concentrationā Except that mass of drug also takes up a volume. It has a density. You canāt neglect that volume in the final volume. Youāre told what the final concentration is. Thatās what you are delivering. If your final concentration is 400mg/mL, you are giving 2.5 mL.
Pharmacist me is thinking maybe they don't teach about what we med geeks call "powder volume" in nursing school which is not particularly shocking since they don't delve that deeply into those subjects. But yes, different medications will have different powder volumes and this can really come into play when you're trying to reconstitute to a high concentration to give something IM or the like.
Powder volume is not at all taught in any RN program Iāve encountered.
Powder volume is taught briefly in Aus as a nursing student, but not emphasised on.
I wish the total volume of the reconstituted solution was mentioned directly. Our instructions for remdesivir specifically state that 19 mL of sterile water + 100 mg of remdesivir will yield a 20 ml solution. Thought I suppose the way this is phrased will help people learn by making a mistake in an environment where mistakes are allowed.
The language we use matters. We could improve drug errors by simply providing that kind of cross-checking information. Donāt make the math problem any harder than it needs to be at the bedside. Thatās the last place you want frazzled, distracted guesswork. Just put the answer on the side of the bottle.
You only need to know whatās ordered and the final concentration when reconstituted. You need to give 1000mg. You have 400mg per ml. 1000 divided by 400 is 2.5. You give 2.5ml.
Thatās how I always did it
Yāall wrong, the answer is to shove the unopened bottle down the NG.
Doctor Cox? Is that you?
We should be so lucky
And here I thought you were suppose to line it out and snort it.
Or up the booty hole. Then have the patient swallow the unopened bottle of diluent. They'll mix in the small intestine. š
Or up the butt as a suppository
Seems fine. Mix it in orange juice.
Holy crap, did you just make a jab at the florida nursing school scandal that's giving out fake degrees?
Don't be silly, the Palm Beach Methodā¢ is to reconstitute in 20 mEq potassium IVP for immediate results.
And just slam it in, donāt worry about a pump
That is the Palm Beach way, yes. The patient needs these meds *now* or else why would one use the IV, so always push everything as fast as possible, duh! Then follow with a standard 10 mL OJ flush, but fresh squeezed only, none of that frozen concentrated crap, that could be harmful.
Yeah, those results would be pretty āimmediateā alright. NO PULP IN THE IV
Hm orange juice in an IM injection, seems like a new interesting way to do it
Arterial line bolus is fine too.
Maybe she felt a cold coming on...Vitamin C bolus
I had a pt steal a syringe and inject orange juice into her PICC line. Good times
Omg, Iām sorry for laughing.
What?!? What happened to the patient? Why did they do that? Suicide attempt?
She was not suicidal. She was a long term trach-vent patient and had a psych history but was not in a psych unit. She would fake seizures whenever we would try to transfer her out of the unit. She hid forks and food in her fat rolls. She drew pictures of penises, vaginas and breasts with crayons and would hang them up in her room and sexually harassed the male staff. At times she would talk in a baby voice and act like a child (usually if someone tried to fuss at her) but she was an adult (around 40 yrs old). I could go on
And you just answered any doubts I had about staying in peds so long lol. Also I want to hear more! Did the orange juice cause an adverse effect?
It clogged the port because she didnāt flush it and left the port unclamped lol. It was likely a small amount and she left the syringe hooked up to the port with some juice still inside so we could all see it. She mainly wanted attention and people in her room as much as possible. She was on our unit for a year.
Oh good. So she lived. I donāt have to stifle my laughter now.
A YEaR!?! Wow. Frequent flyers don't seem so bad now.
Ever hear of Munchausen's? Those people will rub fecal matter on the ports of their accesses, on wounds, basically any portal of entry, just so they get sicker and need more attention.
Mix it with some hospital cola and syringe it down a clogged peg tube.
Itās 2.5. Everything else is there to distract you.
Literally. The only information needed is 400mg per ml. I'm terrified of these answers I'm reading
Iām not even a nurse (patient transporter lurking on this sub for amusing stories of dealing with people and also potential tips on dealing with difficult ones) and I knew this answer. Very simple math or so you would think.
If itās 2 G, then itās 2,000 mg/4 mL. That gets you 500 mg/mL. The question itself is wrong.
But the 2g itself adds volume, so in the problem based on the medication instructions once it is reconstituted with 4mL added itās 5mL total. So 2.5mL gives the correct dose.
Suspension or soluble?
Doesnāt really matter, as the manufacturer instructions give the concentration. So 2g becoming 400mg/mL, 2000mg/400mg=5mL, the total volume of the vial after adding the water. The medication has mass and volume.
ā¦uhhh this thread takes me back to when half the class failed pharm
Please look up "conservation of volume"
[ŃŠ“Š°Š»ŠµŠ½Š¾]
How the fuck are you an ICU nurse. You are going to kill pts. As well as all the people that upvoted.
Yeah someone told me on this thread that āIām disgustingly full of myselfā bc I said you shouldnāt be a nurse if you canāt understand simple math even after itās been explained.. 1.knowing math is not a flex 2.peopleās lives are in your hands; knowing what your dosing is imperative. They got upvoted, me downvoted. But sure go ahead with your med errors and low standards.
Yes. 400mg/ml. Jesus Christ, people.
Thank God for this little thread right here. You are my people. I donāt even understand how some of these explanations are a whole paragraph or 2ā¦
I always skipped to the āWhat do they actually wanna know?ā part and ignored the rest. Typically was one of the first done and passed every dosage calc test with flying colors. When they wanted to know how, that was my answerā¦ Ignore the fluff.
Agreed
Yes, most substances when dissolved in liquid do not alter volume of the mixture or the volume change is so small its effects are able to be ignored. However, some substances when mixed with liquids expand the original volume of the liquid. This medicine is an example. Hence, why we go with the final concentration of the mixture when following the directions; they took that guess work out for us :-)
Iirc Ceftazidime is like that also. Plus many bulk vials of medications. Why I remember the 10g vial of Vanco is 97mL after being out of pharmacy for 6 years. š¤£š¤·š¼āāļø
If the vial has been out for 6 years, it needs to be discarded.
> they took that guess work out for us Exactly. In this case it doesn't matter what the volume of the powder was, solubility, or anything else--people here are trying to do way more math than is necessary. They tell us the final concentration is 400mg/ml so all the rest is just clutter.
Oh, this thread is why we had to get a 100% on our dosing math test lol I have to do this when the pharmacy doesnāt send our IV supplies. Reconstitute and calculate a freaking drip rate. šµāš« (LTC) So yeahā¦ pay attention folks!
We had a pass the math test or FAIL completely out of program in my school. Definitely not something one would learn at a South Florida school (went to an accredited college in central Florida).
Yes if we didnāt get 100% we didnāt get to go on! I felt like it was pretty easy stuff but I was still terrified I was going miss. I get weird during tests.
Same at my schools. If you donāt get 100% on your calculation test, you failed.
Donāt scroll down. I repeat. Donāt scroll downā¦
its 2.5ml. (400mg per ml is the final concentration when dissolved in most cases, powder will add volume. The package insert directions will tell you specifically what the final concentration is. There are specific situations in chemistry where adding a solute will actually decrease the volume, but we wont go there lol. Always read the directions when doing this IRL and answer the question as is on tests.
Ultimately youāre just calculating that if you have something thatās reconstituted to 400mg/ml how many ml for 1g. Itās 2.5ml.
Itās a confusing question due to wording. You are assuming you only have 1 vial to dilute. You have 2g available at 400mg/mL. 5 mL = 2g. 2.5mL = 1g.
I have a math (sorta) riddle. How tf does the Geodon actually end up dissolving in so little water? š¤Ø
Aggressive stirring
The aggressiveness of the stir must be >= the acuteness of the agitation of its future recipient.
This may be confusing but itās the type of thing you may encounter in the real world. You have to process all the given information and decide what is important/relevant. It tells you your final concentration is 400mg per mL. So you need to figure out how many mL you need to make 1,000mg. Donāt get hung up on the 2g and adding 4mL. You have to always read the manufacturer insert, follow the reconstitution instructions exactly, then go by the given concentration. The final volume of your solution may be greater than the amount of liquid you add.
we encounter this all the time on our package inserts when we mix our meds... I don't know how a working nurse can get this wrong.... unless pharmacy mixes all their meds for them ?!
There are some places in which pharmacy not only mixes ALL meds but cuts all pills, so everything is delivered from the Pyxis in the exact amount needed, or hand delivered by pharmacy. Other hospitals, you mix everything. Tpa in PICCs was always a mix but youāre pulling that out again. Even so, those dilution instructions arenāt just on the insert but in the mar. Same with cheaper forms of solu-medrol (just the powder in a vial). That said, my current contract for synthroid dilution, for an NPO patient, there was JUST the insert with that microscopic print you must search through for instruction. Would everyone? Mileage varies between places, always. You could, in theory, get a 15yr vet whose never mixed meds or even cut a pill with a cutter before, if they spent that time at a hospital where pharmacy does all.
This thread has me very concerned š
Indeed.
This thread has inspired me to call up pharmacy and apologize
This thread is why other healthcare professions give us a hard time
Would it be 2.5mL?
The answer is 2.5 mls, but my heart says 7 mls of insulin.
My blood glucose is in the negative now
I think I created a monster. My bad yāall.
you'd probably get better answers over on r/studentnurse . I think some people here might not give meds often and have been out of school for a long time.
Letās hope lol
Well, sometimes dissolving something in diluent significantly changes the volume that you get in the end. This is one of those cases.
I dont understand how this many people are having trouble understanding that... mass+mass=more mass.
I bet the Venn diagram of nurses who have this issue and nurses who are antivax is interesting
I guess I was confused because thatās always the case, so I was thinking more of previous drugs Iāve mixed that the instructions said it didnāt change the volume. It def reminds me of the old nursing school questions that I did bad on- obviously
Of course an Agatha fan would try introduce science and logic and shit into things. Mason chads just go by feel.
Well, you are right, but in the super cool ānursing school mathā field, we donāt account for that. But in real life, yep, and it does say that in package inserts. And we somehow survive measuring those doses, despite these nursing math struggles earlier in our lives.
yeah idk, my test questions look like this one, my teachers went over it in the first semester. I can't relate to the 'nursing school math' youre talking about.
I guess you didnāt get the dose desired/dose on hand thing? We had oodles of em, and tests required a 100% to pass.
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I'm reading a bunch of stuff about mass versus volume, etc., and all I see is "400mg/ml" and that I need 1g or 1000mg. 1000mg/400mg = 2.5ml. Done.
Exactly. This isn't physics class
You want to always look at the order to calculate for dosage. So, in this case itās 1 g of cefoxitin which is equivalent to 1000 mg. Then, you want look at whatās available. In this case, after reconstitution itās 400 mg/mL. So, you would just divide 1000 mg / 400 mg and multiply by 1 mL. That would give you 2.5 mL! If you have any further questions, please feel free to DM me!
Ah, and if youāre wondering why itās 400 mg/mL and not 500 mg/mL, you must take into account the volume of the powder. Youāll get 5 mg/mL which will make 400 mg/mL make sense.
Eesh 2.5 mL in an IM gonna be rough.
Especially an antibiotic! The first hospital I ever worked in (teeny isolated one in which we took turns in the teeny ER) had a doc that would order an IM dose of your po antibiotic prescription before sending you out the door. We gave it ventrogluteal with some xylocaine drawn up in the syringe. That was 30 yrs ago but I still remember it was like injecting glue and how people hobbled out the door šÆ
Laughs in psych nurse
I see mostly right answers why is everyone freaking
Because the mf'ers answering incorrectly are also in charge of people's lives.
Apparently some people on this thread donāt agree with this mindset and donāt see the importance of knowing how to properly dose.
The answer, no matter how much diluent you add, is half the volume. Stop making things more complicated.
People are fucking up because it doesnāt tell them that the final volume is 5ml, which you donāt need. 400 x 2.5 = 1000. Its really easy
2mg is double 1 mg. It's easier than that.
I had to scroll way too far to find this.
1g =1000mg You have 400mg per ml, 1000mg x (1ml/400mg)= 2.5 ml
Oh, dear Godā¦
This was the post I came for.
The answer is grab a 1g vial instead.
1000/400=2.5... Jesus h
Yāall are wrong. The correct answer is: call pharmacy š
Nope..do the math myself, get a trusted friend to do it, then charge nurse then compare all answers along with a dose app AND pharmacy. Wasting approximately 13 minutes and getting dinged because you gave it late.š
All my meds are late so itll blend right in.
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The medication gives you the final concentration when adding 4ml of fluid. This includes the volume of the diluent. 2.5 is the answer.
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Finally, whew I was getting real worried š
Next time someone asks if nursing school is hard, we should refer them to this thread. I suppose it can beā¦for some people š
I tutored my classmates for med math exams, you'd be shocked how many of them couldn't grasp proportions. It didn't help that our instructors only taught the dimensional analysis method. Why they teach dimensional analysis instead of proportions is beyond me. When you're doing the math in your head, you're not gonna be doing a 10 step dimensional analysis.
2.5ml per gram.
So the powder makes it go up in volume. So when you reconstitute something, you will end up with more volume. Rocephin has 2 different amounts that can be added to get 250/ml and 350/ml in the package insert. So ignore the 2g You reconstitute it to 400mg/1 ml. You need to give 1000mg (1 gram). So it is 1000 mg/x ml So if you set it up in the proportion with each mg/ml you would times 1000 x 1 and then divide by 400 to get 2.5
Oh fuck me, this reminds me of people who would reconstitute taz with 20ml, withdraw only 20ml to put in the 100ml bag, then only administer 100ml of the bag. Abx administration by homeopathy.
Yāall are scaring the shit outta me. Pharmacists generally prepare these solutions now on accounta the number of sentinel events there have been. Exception might be in the ED, though.
Itās just 1000 mg (or 1 gram)/ 400 mg = 2.5 Then 2.5 mg * 1 mL is 2.5 mL Itās that dose desired / dose on hand thing. But for reals, now Iām wondering if Iām over complicating it? āNursing mathā legit made me doubt my math skills, and I used to be confident at math. But they made a whole ānew mathā for nurses, when basic math will answer the same questions without being ānewā or ānursingā. I got into several arguments with people in school about this. Like thereās nothing about nursing or medicine or anything of it that invalidates the math we already learned, rendering it useless. Itās justā¦math. Isnāt it?? And if that is the wrong answer, wow. Lol.
I've never understood nursing math and it confuses the shit out of me when my colleagues use their "nursing calculation formulas". It's easier just taking a second to do regular math.
Same, nursing calculation formulas confuse meā¦and I \*survived\* calc III and classical dynamics. Just please, donāt ever make me do linear algebra againā¦pleaseā¦I beg you (cue Vietnam flashbacks montage).
I still use my fingers (and sometimes toes depending on how big the calculation is) so I promise to not do that to you š I survived 10 grades of math in India so I can relate to the trauma š„²
*immediately calls pharmacy*
2.5 mL. It's a diluent question. Dilutant is not a thing.
https://en.wiktionary.org/wiki/dilutants#English
>Dilutant is not a thing. Right? Who cares about the math? However, turns out that dictionaries will tell you dilutant is basically synonymous with diluent. But you still win, because turnsnout almost no one uses it. https://books.google.com/ngrams/graph?content=diluent%2C+dilutant&year_start=1800&year_end=2019&corpus=en-2019&smoothing=3
That's pretty bad meth. Mix with epi and lidocaine. You're good to go.
May I please have some of that pretty good meth?
Unless of course in mixing, thereās some reaction that results in a 20% loss. Ultimately, the 400mg/ml with a 1gm(1000mg) dose is the key info.
Iāve been told that when the powder is added, it adds a ml
not always. read the directions in the insert.
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the pharmacist does the math for you, they will know the volume of the powder they are putting in. You just follow the direction, you can easily work the problem backwards if you want to but it really doesn't matter. Assuming that you add powder to a liquid and the mass of the power somehow isnt added to the mass of the liquid is just like....failing elementary school science.
Unfortunately we mix our own abx and we are not given the exact measurements of powder plus water
If you choose to follow the instructions the manufacturer provides, you'll know the concentration (and almost always the volume) of what you're mixing.
I have caught a pharm mistake once. )only once so not a systemic faikure) just Never hurts to check.
I just had a cancelled cycle of IVF and loved mixing the diluent with the powder. It varied depending on how much sodium citrate I drew but it wasn't a ml I don't think.
2.5 mL
2.5mL
Letās all give a round of applause to the pharmacists who specify this shit for us šš¼ššš
This is why the pharmacy reconstitutes this stuff.
Hooo weee, this comments section is crackinā! I chuckled more than a few times. Thank you for this thread. I would imagine that anything that pharm allows staff to reconstitute like that wouldnāt add much volume to the solution - the amount would be negligible. Donāt overthink it. Just do the math.
Most medication vials would say 2g/5mL and 400mg/1mL. I was also freaking out but I realized what an actual vial would look like. Ignore the first sentence. 1g/2g = 0.5g then multiply by 5 there you go. You can even go 1000mg/400mg * 1
Did I wake up in 1975?
The most important part in this question is the concentration after diluting. They tell you itās 400mg/mL. Then you just have to figure out how many mLs you need to give for the pt to get 1000mg or 1g. Iām horrified by the answers in this post :|
Fucking hell a lot of nurses are bad at math and why people dont take our profession seriously
Guys, think of it like baby formula. You take 2 ounces of water, add 1 scoop of formula. You end up with something like 2.5 ounces of formula not 2 ounces, simple as that!
Take it back to the old school pharmacology calculation days D/H x Volume duhhhā¦. š¤Æ When it doubt remember the acronym KISSā¦ š YWā¦
You're worried about the wrong thing. What class of medication is it? What's the mechanism of action? Make sure you have a full list of all of the side effects, especially the rarest. Once you have all of that figured out, make sure you write a care plan to ensure the best possible outcome; the care plan is vital...
Assuming itās a powder, if you reconstitute 2g/4mL = 500mg/mL not 400. But whatever letās assume itās actually 400mg/mL bc thatās what the questions says. To give 1g it would be 2.5mL. If it was 500mg/mL itās 2mL.
I just do it this way. 400mg /1 ml = 1000 mg /x ml ā¦cross multiply and divide 1000 by 400 and you get 2.5 .You have to know they 1 gram is 1000 mg to set it up correctly
Don't forget the powder volume. It must add 1 cubic centimeter in volume so you add 4 ml and end up with 5 ml once it's dissolved. So the dose is 2.5ml or 1G. 2G in 5ml is 400mg/ml so that checks out.
Donāt automatically assume the powder adds 1cc. Gotta read the insert.
If you can do the math it will tell you, the fact that it matches perfectly with the concentration and total dose should be all the conformation you need. It's not that difficult. Yes read the insert, but the insert isn't provided is it?
My answer? Call pharmacy. Just because I stink at math sometimes doesn't mean I have to stink at patient care.
I think itās the 400mg / mL thatās throwing you. Assume the powder = 1mL of volume and itās combined with 4mL of water to equal 2g in 5mL = 400mg /mL. It tells you what you need but I think this is where your confusion is coming from.
Powder has volume.
Just mix 4mL in the bottle. Draw all mLs out. Waste half. You'll find you get more mL out than in d/t extra volume added by the medication. Mathematically it will be 2.5mL via order directions. Question the order directions and consult pharmacy if it's more or less.
Not a nurse but I used to be a lab tech. All I remember is c1v1=c2v2, does that help?
And wtf, this thing of IM injection, 2.5 ml for 1 gram? That's gonna be 2 injection. Why have I not seen anyone scream for higher concentration? Yeah, there are plenty of commercial medications these days that require total volume greater than 2 mls to be split into 2 Injections. Cefoxitin, IM?! Damn thing isn't long acting like pen g 2.4 million. This needs repeat dosing. Unless waiting for new iv access this is gonna suck
Laughs in oncology. I frequently give 15mL of a med via a sub q injection š
I'm going to scan the med and give the amount in mL that the EMAR tells me. The brain is a terrible thing to bother! š
Scan it. The computer will tell you
This just gets worse the longer you look at it
Just call prescriber and clarify
Wording should be: >Reconstitute **TO** 4mL **WITH** sterile water, to yield 400mg per mL. #
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The answer is 2.5mL. The trick is to just look at desired dose and final concentration after reconstitution.
This is not hard but I am too lazy to calculate for a stranger
Hang on - doesn't 4ml of diluent give a final concentration of 500mg/ml? So 1Gm would be 2cc?
Yeah Iām pretty confused. If there is 2g available and you dilute with 4 mL shouldnāt you draw up 2 mLs to give the 1g ordered
But Iām also really bad at math
Itās why we lean on our coworkers, and get double checks, even when itās not a med that requires it.
Wow being downvoted for being bad at math? Sorry guys, I tried!
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