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c/reconstitution·posted 2 years ago by u/batch_number_bertie

[PSA] dead space is not what most of this community thinks it is

PSA Clean Column ×9

Trying to settle this properly because the thread from last year went in circles.

The claim: insulin syringe matters. The counter-claim: it is measurement error. Both sides have been asserting it confidently for about 21 months without either producing anything.

What would actually settle it is 33 people measuring the same thing the same way. I have started; my numbers are below. They lean one way but not strongly enough for me to declare victory.

If you have data, post the data. If you have an opinion, flair it as an opinion.

709 up / 28 down96% upvoted19 commentsid kla4mw23 Jul 2024

19 comments

17 in this archive, depth 5

best — the order this archive was captured in

u/honest_syringe_maybe64 points·2 years ago

dead space is real and the syringe matters

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u/vito_beaulieu0 points·2 years ago

Disagree. What you are describing is consistent with mg/mL, not with what you concluded.

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u/emil_okwuosa1 point·2 years ago

bacteriostatic and sterile water are not interchangeable, do not use them that way

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u/batch_number_bertieOPvetting1 point·2 years ago

The single most useful thing I did was write the concentration on the vial. Stopped all the confusion after that.

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u/gradient_goblin1 point·2 years ago

The single most useful thing I did was write the concentration on the vial.

Yes, exactly this, and it is the bit that took me 24 weeks to accept.

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u/erez_perrin1 point·2 years ago

dosing errors come from people reconstituting two vials differently and forgetting which is which

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u/marisol_frisk53 points·2 years ago

No. This is the kind of confident post that gets copied into a screenshot and repeated for years. Where is the evidence.

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u/sigrid_kaufmann25 points·2 years ago

Not convinced. The evidence does not support that reading.

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u/batch_number_bertieOPvetting15 points·2 years ago

Cosigning. The concentration on the vial in marker is load-bearing.

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u/elin_ferrari0 points·2 years ago

show your working or it is unhelpful

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u/nadia_kjaer42 points·2 years ago

Yeah, showing the arithmetic is the fastest way for someone to spot the error.

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u/hedda_ekstrom31 points·2 years ago

Reconstituted at 3mL when I meant 2mL. Caught it because the units looked wrong. Write the concentration.

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u/honest_syringe_maybe21 points·2 years ago

Spent 4 weeks confused about concentration math until someone showed me the table. 5mg, 1mL, concentration is 5/1.

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u/cardio_endpoint_c9 points·2 years ago

never post a calculation as advice without stating the concentration

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u/batch_number_bertieOPvetting20 points·2 years ago

This is correct. 2mL versus 24mL is the common mistake.

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u/swirl_dont_shakereconstitution23 points·2 years ago

The confident tone is doing a lot of work that the evidence is not.

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About c/reconstitution

The arithmetic and the technique. Bacteriostatic versus sterile water, reconstitution volume as a concentration choice, converting mg/mL into insulin-syringe units, dead space, swirl-not-shake, stopper coring, and how long a reconstituted vial is actually good for. Math errors get corrected fast and politely.

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