Topic summary

A ten-fold dose error caught before injection — one year on

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

This is a generated summary. It shows the 9 most-liked posts from a topic of 158, 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.

m.mwangiTL2 Moderator1 Aug 2025#15

ni.stanescu, post #8: On post #4 — agreed on the reasoning, with one qualification. Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive. Go to post

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.

32 likes in reply to #8 12mo

ro.zielinskiTL2 Moderator1 Aug 2025#24

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.

30 likes 12mo

h.oyelowoTL2Regular1 Aug 2025#32

m.radich, post #31: Aspirating before injection: for subcutaneous injection, aspirating (pulling back on the plunger to check for blood) is not necessary and is sometimes discouraged because it is associated with more discomfort. Subcutaneous injection without aspiration is standard practice. Go to post

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

28 likes in reply to #31 12mo

cannula_traceTL3Regular2 Aug 2025#48

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.

27 likes 12mo

WickramasingheTL2Member3 Aug 2025#63

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.

27 likes 12mo

blank_injectionTL2Analytical chemist3 Aug 2025#80

ambient_review, post #5: Picking up post #2: that is the part I would want checked first. Aspirating before injection: for subcutaneous injection, aspirating (pulling back on the plunger to check for blood) is not necessary and is sometimes discouraged because it is associated with more discomfort. Subcutaneous injection without aspiration is standard practice. Go to post

Picking up post #77: that is the part I would want checked first.

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.

27 likes in reply to #5 12mo

diluent_watchTL2Member3 Aug 2025#86

Coming back to post #84, because the follow-up matters more than the original answer.

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.

28 likes 12mo

a.pereiraTL2 Moderator3 Aug 2025#96

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.

32 likes 12mo

m.adeyemiTL2 Moderator4 Aug 2025#132

I read post #130 twice before replying, because I had assumed the opposite.

28 likes 12mo

Read the full topic (158 posts)

Suggested topics

Topic	Participants	Replies	Views	Activity
Reading U-100 graduations, with a conversion table Devices › Syringes & needles dead volume worked example subcutaneous injection needle gauge & length Posting this under the heading it deserves: Reading U-100 graduations, with a conversion table Everything below is what sits behind that. Practical question with the units stated, because I have seen how…	+35	41	2k	1d
Follow-up: Dead volume across syringe and needle combinations Devices › Syringes & needles syringe units worked example subcutaneous injection dead volume Solved Dead volume across syringe and needle combinations — setting out what I have, and where I think it stops being reliable. Practical question with the units stated, because I have seen how quickly these go…	+81	98	22k	18mo
About the Syringes & needles category Devices › Syringes & needles syringe units dead volume needle gauge & length Pinned Wiki Insulin syringe graduations, dead volume, gauge and length selection, and reading units correctly. This post is a community wiki: any member at trust level 3 or above can edit it, and every edit is recorded…		4	45k	1mo
Fixed versus detachable needles: the trade-offs Devices › Syringes & needles dead volume subcutaneous injection syringe units worked example Solved Posting this under the heading it deserves: Fixed versus detachable needles: the trade-offs Everything below is what sits behind that. I have read the maintained page on this and I still have a gap, so I am…	+117	121	7.3k	18mo
Gauge and length selection for subcutaneous injection Devices › Syringes & needles syringe units needle gauge & length worked example subcutaneous injection Solved Gauge and length selection for subcutaneous injection Writing it up because I had to work it out twice and would rather nobody else did. Practical question with the units stated, because I have seen how…	+50	55	1.3k	8mo

Related topics — sharing the tags dead volume, needle gauge & length, subcutaneous injection

Topic	Participants	Replies	Views	Activity
A site rotation scheme that is easy enough to actually follow Practice › Administration needle gauge & length missed dose injection site rotation aseptic technique On the subject in the title: A site rotation scheme that is easy enough to actually follow Working notes rather than a conclusion. Practical question with the units stated, because I have seen how quickly…	+112	125	5.8k	21h
Second pass at: Choosing a concentration on purpose rather than by accident Practice › Reconstitution worked example dead volume reconstitution Second pass at: Choosing a concentration on purpose rather than by accident Writing it up because I had to work it out twice and would rather nobody else did. Practical question with the units stated, because…	+44	48	1k	19mo
Dead volume across syringe and needle combinations Devices › Syringes & needles needle gauge & length subcutaneous injection dead volume syringe units On the subject in the title: Dead volume across syringe and needle combinations Working notes rather than a conclusion. Practical question with the units stated, because I have seen how quickly these go wrong…	+72	80	28k	5mo
Coming back to: Swirling versus inverting versus leaving it alone Practice › Reconstitution reconstitution concentration maths syringe units Solved Swirling versus inverting versus leaving it alone Writing it up because I had to work it out twice and would rather nobody else did. Practical question with the units stated, because I have seen how quickly…	+20	24	16k	26d
Feature request: should a dose-equivalence tool exist at all? Data & Tools › Calculators site feedback worked example concentration maths syringe units Closed Feature request: should a dose-equivalence tool exist at all? — that is the question, and I have not found it answered plainly anywhere I have looked. Posting the method first, because I know what the first…	+21	25	4.8k	18mo