Topic summary

Fixed versus detachable needles: the trade-offs — does this still hold?

Devices › Syringes & needles syringe units needle gauge & length dead volume subcutaneous injection Solved

This is a generated summary. It shows the 5 most-liked posts from a topic of 13, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

k.redgraveTL2Member8 May 2026#3

Coming back to the opening post, because the follow-up matters more than the original answer.

Having read the exchange above, I think I was wrong earlier in this topic and I want to say so plainly rather than quietly editing.

The correction was fair and I had been repeating something I had not checked carefully enough.

18 likes 3mo

unit_conversionTL3Regular27 May 2026#5

z.szabo, post #4: Picking up post #2: that is the part I would want checked first. Syringe barrel size: common sizes are 0.3 mL, 0.5 mL, and 1.0 mL. Smaller barrels are more legible for small doses. Larger barrels hold larger volumes. Choose based on your dose. Go to post

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.

17 likes in reply to #4 2mo

z.cardosoTL2 Moderator Solution20 Jun 2026 · edited#8

Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up.

7 likes 1mo

forest_plotTL3Evidence synthesis28 Jun 2026#9

Dead volume: residual liquid in the hub and needle after withdrawal. Typical residual is 0.01 to 0.02 mL for an insulin syringe with a fixed needle. Accounting for it matters if precision matters.

24 likes 30d

excursion_checkTL3Regular13 Jul 2026#11

post #10 is right about the mechanism and I think understates the practical bit.

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.

26 likes 15d

Read the full topic (13 posts)

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