Topic summary

A ten-fold dose error caught before injection

Devices › Syringes & needles needle gauge & length worked example syringe units dead volume Closed

This is a generated summary. It shows the 9 most-liked posts from a topic of 104, 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.

RidgewayTL3Regular26 Feb 2025#4

cohort_notes, post #2: Graduation spacing is worth checking before you buy rather than after. Some 1 mL barrels are marked every two units and some every one, and that changes what doses you can read. Go to post

Post #3 answers the question as asked. The question underneath it is different.

Two claims get bundled together under ten-fold dose error caught and they need separating. The descriptive one — this is what was observed — is usually well supported. The causal one — this is why — usually is not.

Almost every disagreement in threads like this one dissolves once you say which of the two you are making.

31 likes in reply to #2 17mo

c.grimaldiTL231 Mar 2025#15

n.nyberg, post #12: Nothing to add, except that this is the answer I would give if asked. Go to post

Post #13 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.

28 likes in reply to #12 16mo

DOdendaalTL3Regular15 Apr 2025#21

c.grimaldi, post #15: Post #13 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. Go to post

Everything in post #20 holds. The case it does not cover is the one I have.

A note on scope: what I am saying about ten-fold dose error caught applies to the case in the first post and I would not extend it further without checking.

30 likes in reply to #15 15mo

d.tammTL212 Jun 2025#48

Post #46 is right about the mechanism and I think understates the practical bit.

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.

30 likes 14mo

a.novakTL214 Jun 2025#49

s.antonsen, post #33: If someone has run ten-fold dose error caught properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet. Go to post

Answering the question post #46 raises rather than the one it answers.

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.

Two sources, same conclusion, and I could not rule out that one copied the other.

29 likes in reply to #33 13mo

impurity_tableTL3Analytical chemist28 Jun 2025#56

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.

The strength of my opinion here exceeds the strength of my evidence.

32 likes 13mo

p.iyer_pharmdTL3Pharmacist7 Jul 2025#61

f.demir, post #52: 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. That distinction has done more work for me than anything else in this category. Go to post

On post #59 — agreed on the reasoning, with one qualification.

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.

32 likes in reply to #52 13mo

batchlogTL3Regular8 Sep 2025#96

Clear enough that I do not think I have a follow-up, which is unusual.

29 likes 11mo

j.castellanosTL221 Sep 2025#104

b.fonseca, post #47: 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. Go to post

On post #100 — agreed on the reasoning, with one qualification.

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.

32 likes in reply to #47 10mo

Read the full topic (104 posts)

This topic was referenced in

About the Syringes & needles categoryDevices › Syringes & needles · 4 replies
Dead volume across syringe and needle combinationsDevices › Syringes & needles · 80 replies
Reading U-100 graduations, with a conversion table — what changed sinceDevices › Syringes & needles · 2 replies

This topic was closed 90 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.

Moved from Cold chain by t.vasquez. Category placement is not obvious from outside and getting it wrong is expected. This topic will get better answers here. The move is recorded in the public log citing R7.

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