Topic summary

Revisiting: Filter needles: when they help and what they cost you

Devices › Syringes & needles worked example needle gauge & length subcutaneous injection dead volume Closed

This is a generated summary. It shows the 8 most-liked posts from a topic of 53, 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.

j.vandermolenTL3Regular19 Feb 2025#2

What I would want before treating Filter needles as settled: the method, the sample, and whether anyone tried to find the opposite result. Two of the three are usually missing.

24 likes 17mo

np_gilmoreTL3Nurse practitioner17 Apr 2025#13

Building on post #12 rather than restating it.

An update on my earlier Filter needles post: the pattern held for another six weeks and then stopped, which I did not predict and cannot explain.

19 likes 15mo

s.dialloTL28 May 2025#18

Filter needles are for drawing from glass ampoules where particulate is a real risk. For a stoppered vial they add dead volume in exchange for very little.

The general answer and the answer for your case may diverge here.

27 likes 15mo

c.dahlbergTL28 Jun 2025#26

This follows post #23 rather than contradicting it.

The quoted dead-volume figures for common configurations vary between manufacturers and the ordering is stable: fixed needle least, luer with hub more, luer with filter needle most.

I am not the right person to answer the follow-up to this.

24 likes 14mo

ambient_reviewTL3Regular22 Jun 2025 · edited#30

Taking post #29 at face value and following it one step further.

If someone has run Filter needles properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet.

32 likes 13mo

h.hutchingsTL1Member6 Jul 2025#34

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.

26 likes 13mo

b.okonkwoTL23 Aug 2025 · edited#42

Gauge is the outside diameter and higher numbers are thinner. Thinner needles hurt less and draw more slowly, which is the entire trade.

20 likes 12mo

v.bhattacharyaTL216 Aug 2025#46

Careful with the language on Filter needles. "Not detected" and "not present" are different findings and the first is a statement about the method.

27 likes 11mo

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This topic was referenced in

Reading U-100 graduations, with a conversion table — one year onDevices › Syringes & needles · 7 replies
A ten-fold dose error caught before injection — one year onDevices › Syringes & needles · 157 replies

This topic was closed 180 days after the last reply. Closing is automatic for quiet topics so that a settled answer does not collect new questions underneath it. If you have a follow-up, open a new topic and link back to this one — that keeps both readable and gives your question its own title.

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