On the subject in the title: A ten-fold dose error caught before injection — one year on Working notes rather than a conclusion.
Two things I would like separated before anyone answers on ten-fold dose error caught, because they get bundled and then argued about as one thing.
The first is descriptive: what has actually been observed, by whom, and how. The second is causal: why. I am asking about the first only.
Post #2 is the version of this I will quote in future. One addition.
Silicone coating on the barrel affects how smoothly the plunger moves and how a very slow injection feels. It is one reason two syringes at the same specification are not identical to use.
Where I part company with the opening post, and it is a narrow parting.
Nobody has said the unglamorous part of ten-fold dose error caught yet, so: most of the variation is explained by things that are boring to write about and easy to check.
Narrowing post #2, because the general version has more than one answer.
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.
Small correction to my own earlier position on ten-fold dose error caught. I had the units the wrong way round, which changes the conclusion by an order of magnitude and therefore changes it entirely.
Second this, and I would have said it less carefully.
Post #6 answers the question as asked. The question underneath it is different.
Sharps containers are a legal requirement for disposal in several jurisdictions and a sensible precaution everywhere. A rigid sealed container is the minimum.
Filing this under things that are true until someone shows me otherwise.
I read post #9 twice before replying, because I had assumed the opposite.
Before the thread moves on from ten-fold dose error caught — what is the sample size behind the claim? I am not being difficult; I have seen the same figure quoted from an n of four and from an n of four hundred.
Worth separating two things that post #7 runs together.
Source for the ten-fold dose error caught figure, since it was asked for. It is in the discussion rather than the abstract, which is why the version circulating is stronger than the paper is.
Reading the surrounding paragraph is worth the two minutes. The authors are more careful than their summarisers.
Barrel size determines resolution and nothing else. A 0.3 mL barrel and a 1 mL barrel deliver the same volume equally well; the smaller one lets you see what you are delivering.
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.
Genuinely open to being wrong about this one.
What would change my mind on ten-fold dose error caught is a second dataset collected by someone with no stake in the first. Until then I hold it loosely and I would rather say so than pretend to more.
Drawing air into the vial before withdrawing liquid equalises the pressure and makes the draw easier. It is not required and it is why some people find a full vial harder to draw from than a half-empty one.
If this contradicts something upthread, the upthread version may well be the better one.
Needle gauge: smaller numbers (30G) are finer and less painful. Larger numbers (25G) are courser. For subcutaneous injection, 27-30G is typical. Finer needles take longer to draw up but hurt less.
Small point, but it is the one that usually catches people.
Confirming post #15 from a second method, which matters more than confirming it from a second person.
On ten-fold dose error caught, the part that usually goes wrong is that the question is asked as though it has one answer. It has a range, and the width of the range is the interesting bit.
If you can post the two or three numbers you are working from, several people here will check the arithmetic rather than argue about the conclusion.
A detachable luer needle plus hub can retain enough volume to matter. Whether it matters to you depends on your dose, and the arithmetic is worth doing once.
Nothing above should be read as advice about what anyone else should do.
Building on post #18 rather than restating it.
Buying a box of the wrong barrel size is the most common regret described in this subcategory, and the reason is nearly always that the dose was decided after the syringes.
That is all I can say without guessing.
Needle length: typical lengths for subcutaneous injection are 4-6 mm (short), 8 mm (standard), or 10-12 mm (longer). Longer needles are needed for deeper tissue or if you have abdominal adiposity.
Speaking for myself and not for anyone else who has posted here.
Answering the question post #18 raises rather than the one it answers.
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.
Reusing a needle blunts it and there is no benefit to offset that. The second injection with the same needle is the one people describe as painful.
Written in the hope of being told what I have missed.
Drawing through a wider needle and injecting through a thinner one is a reasonable approach for a viscous preparation and pointless for an aqueous one.
I am reporting what happened, not recommending it.
Barrel size determines resolution and nothing else. A 0.3 mL barrel and a 1 mL barrel deliver the same volume equally well; the smaller one lets you see what you are delivering.
Noting that I have skin in this question and have tried to discount for it.
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.
A weak preference rather than a position.
Adding thanks rather than a view. I do not have a view worth the space.
Needle length for subcutaneous delivery is a question about tissue depth and injection angle together. Short needles at ninety degrees and longer ones at an angle reach comparable depths.
A methods point on ten-fold dose error caught rather than a substantive one: if the comparison is not like for like, the difference you are measuring is the difference in method.