Fixed versus detachable needles: the trade-offs posts 31–60

Confirming post #43 from a second method, which matters more than confirming it from a second person.

Sharps containers are a legal requirement for disposal in several jurisdictions and a sensible precaution everywhere. A rigid sealed container is the minimum.

I had written a reply contradicting post #42 and deleted it. Here is what survived.

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.

Fixed versus detachable needles came up in a thread eighteen months ago and was answered well. I cannot find it, which is itself the problem, so here is the reconstruction.

Fixed versus detachable needles: insulin syringes usually have fixed needles (no dead volume loss to the hub). Luer-lock syringes use detachable needles (more dead volume). Fixed needles are preferred for small doses.

I would call that likely rather than established.

Right, and stated more narrowly than I would have dared to state it.

Everything in post #46 holds. The case it does not cover is the one I have.

Adding what did not work for me on fixed versus detachable needles, since the failures never get written up and they are half the useful information.

Fixed versus detachable needles 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.

Narrowing post #50, because the general version has more than one answer.

Sharps containers are a legal requirement for disposal in several jurisdictions and a sensible precaution everywhere. A rigid sealed container is the minimum.

The step people skip is the one I have spelled out.

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.

Saving this. It is the version I will quote when the question comes round again.

Taking fixed versus detachable needles 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.

The reason fixed versus detachable needles keeps being re-asked is that the answer is conditional and people quote it without the condition. It is not that the answer is unknown.

Where I part company with post #53, and it is a narrow parting.

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.

Sharps disposal: needles and syringes should be disposed in a sharps container (a rigid, puncture-resistant container). Do not put them in regular trash. Many pharmacies accept filled sharps containers.

Right — I had this wrong and I am glad to have read it before it mattered.

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.