Posting this under the heading it deserves: Reading U-100 graduations, with a conversion table Everything below is what sits behind that.
A question about reading U-100 graduations that I think has a definite answer, unlike most of what I ask here.
I have the reasoning below and I am fairly confident about the direction. I am not confident about the size, and the size is what the decision turns on.
The opening post and I disagree about the size of the effect, not about the direction.
What I would want before treating reading U-100 graduations as settled: the method, the sample, and whether anyone tried to find the opposite result. Two of the three are usually missing.
Answering the reading U-100 graduations question as asked, then the question I think is meant. As asked: yes, with the qualification below. As meant: it depends on how the first measurement was taken.
Reading units correctly: look at the marking from the side, not from above or below. The bottom of the plunger tip is the reading. Parallax error (wrong angle) is a source of dosing error.
Caveat: everything above assumes the paperwork is what it says it is.
Post #2 put the caveat in the right place and I want to underline it.
Taking reading U-100 graduations seriously for a moment rather than deflecting: the honest position is that the community has observations and no controlled comparison, and those two things support very different sentences.
Narrowing post #4, because the general version has more than one answer.
Nothing here is medical advice, and anybody uncertain about technique can have it demonstrated by a nurse or a pharmacist in five minutes, which is a better use of the time than reading about it.
Reading U-100 graduations is well covered in the tag pages, and the older discussions are better than the recent ones because they were argued out properly. Worth twenty minutes before adding to this one.
Agreed on reading U-100 graduations, with one qualification that I think matters. The reasoning holds for the case as described. Change the starting assumption and it does not, and the starting assumption is the part nobody states.
Check what the graduations actually say rather than what you expect. A syringe marked in units and one marked in millilitres look similar at a glance and are not the same instrument.
I would rather be precise about what I do not know than vague about what I do.
Where I part company with post #9, and it is a narrow parting.
A request rather than an answer: could whoever has the primary source for reading U-100 graduations post it? I have seen the claim three times this month and each version had lost a qualifier.
Thank you for taking the time. That was more work than a reply usually is.
I disagree with the framing of reading U-100 graduations above, and I think it is a substantive disagreement rather than a terminological one. Setting out why, so it can be checked.
The reasoning depends on an assumption that is doing a lot of work and is never stated. If the assumption holds, the conclusion follows. I do not think it holds generally.
Insulin syringe graduations: U-100 syringes are marked in units where 100 units = 1 mL. Always confirm your syringe is U-100. Confusion between insulin units and milligrams is the most common syringe error.
Reporting the observation and leaving the explanation open deliberately.
Reading U-100 graduations is one of those subjects where the general answer and the answer for a specific case diverge, and the thread will go in circles until someone says which one is being asked for.
Confirming post #13 from a second method, which matters more than confirming it from a second person.
Practical note on reading U-100 graduations: write down what you expect before you look. The number of times I have found what I went looking for is higher than chance would allow.
For anyone finding this later: the short answer on reading U-100 graduations is that it depends on one thing, and the rest of the thread is people identifying which thing.
Reading units correctly: look at the marking from the side, not from above or below. The bottom of the plunger tip is the reading. Parallax error (wrong angle) is a source of dosing error.
Two sources, same conclusion, and I could not rule out that one copied the other.
I read post #20 twice before replying, because I had assumed the opposite.
U-100 means the barrel is graduated for a solution containing one hundred units of insulin per millilitre. For anything that is not insulin, the units are simply hundredths of a millilitre.
That is the practical version. The rigorous version is longer and says the same thing.
Taking post #22 at face value and following it one step further.
What I can speak to on reading U-100 graduations is narrow, so I will keep it narrow rather than generalising from it. Beyond that boundary I do not know.
Since reading U-100 graduations keeps coming up, it should probably be a maintained page rather than a recurring thread. I am happy to draft it if someone with more direct experience will review it.
Following, with nothing to contribute beyond having asked the same thing elsewhere.
Post #29 describes the usual case. This is about the unusual one.
Reporting rather than recommending, on reading U-100 graduations. What happened is above. Whether it should have is a different question and not one I am qualified to answer.