[Question] how do you actually verify insulin syringe
Asking properly rather than in a comment on somebody else’s thread: how do you actually verify insulin syringe. Shook the first vial because nobody told me not to. It was fine, but I have swirled every one since. Wrote the date on the vial as well as the concentration after losing track of which one was opened first.…
Careful — that arithmetic is wrong. 5mg in 3mL is 1.67mg/mL, so 0.25mg draws to 15 units, not what you wrote.
Asked CPC what volume they reconstitute to for their own stability testing and they answered in one line. Useful thing to know.
The lyophilised cake displaces a small volume, so the true concentration is very slightly lower than the arithmetic suggests. It is a fraction of a percent and it is dwarfed by fill tolerance.
The arithmetic in full: concentration is mass over volume, so 20mg into 2mL gives 10mg/mL. A U-100 syringe is graduated at 100 units per millilitre, so 2.5mg is 2.5 divided by 10 millilitres, which is 25 units.
Spent 24 weeks confused about this until somebody drew the table for me. 10mg, 2mL, 5mg/mL, 0.75mg is 15 units. That is the whole thing.
Reconstituted at 3mL when I meant to use a different volume. Caught it because the units looked wrong on the barrel. Now I write 10mg/mL on the glass before I put the cap back.
This. Showing the working is the fastest way for somebody else to spot the mistake.
I keep a laminated card in the drawer with the arithmetic on it. Looks ridiculous. Has never once let me draw the wrong volume.
I keep a laminated card in the drawer with the arithmetic on it.
Disagreeing with this line only: adding more water is not a safety margin, it is a different divisor.
Yes, and the dead-space point is worth repeating: it is small, it is real, and it is the same for every draw.