[Discussion] the dead space advice in here is 3 years out of date
Thinking out loud about this: the dead space advice in here is 3 years out of date.
The relevant figures are 3 years, and they come from the same log I have kept the whole time.
The arithmetic in full: concentration is mass over volume, so 15mg into 1mL gives 15mg/mL. A U-100 syringe is graduated at 100 units per millilitre, so 1.5mg is 1.5 divided by 15 millilitres, which is 10 units.
Started reconstituting everything to a round concentration and the six-in-the-morning error rate went to zero.
Corrections welcome, especially the pedantic ones. Pedantry is how this board earns its reputation.
best — the order this archive was captured in
Research-use-only material is not approved for human use, so treat everything in this thread as arithmetic about solutions rather than instructions for a person.
I keep a laminated card in the drawer with the arithmetic on it. Looks ridiculous. Has never once let me draw the wrong volume.
Research-use-only material is not approved for human use, so treat everything in this thread as arithmetic about solutions rather than instructions fo
Disagreeing with this line only: adding more water is not a safety margin, it is a different divisor.
The whole calculation, once, with real numbers.
You have a 5mg vial. You add 1mL of bacteriostatic water. Concentration is mass over volume: 5mg/mL. A U-100 insulin syringe is graduated at 100 units per millilitre, so one unit is 0.01mL.
To draw 5mg you need 5 divided by 5 millilitres, which is 100 units on the barrel. Write "5mg/mL" on the vial in marker before you put it away, and you never have to do this again for that vial.
Same. I got this wrong once, caught it because the units looked absurd, and have written on every vial since.
How many mg in the vial and how many mL are you adding?
Wrote the date on the vial as well as the concentration after losing track of which one was opened first.
Yes. Writing 10mg/mL on the vial takes four seconds and removes the entire class of error this board exists to fix.
What is written on the vial right now?
Did the maths give you a whole number of units, or a fraction?
10mg into 1mL is 10mg/mL, and 0.5mg of that is 5 units
Bacteriostatic or plain sterile water?
Is that a U-100 syringe? The barrel markings change the answer completely.
label the vial with the date as well as the concentration
Are you accounting for the powder volume, or is that where the confusion is?
- 1Wrote the date on the vial as well as the concentration after losing track…7 comments in this branch · started by u/sigrid_kaufmann