Tags · Practice

dead volume

Residual liquid in hub and needle, and the dose it silently removes.

49 topics 13 solved Group: Practice

49 topics · page 1 of 2

Topic	Participants	Replies	Views	Activity
Reading a syringe in poor light, and how to avoid needing to Devices › Syringes & needles syringe units dead volume needle gauge & length worked example Solved Reading a syringe in poor light, and how to avoid needing to Writing it up because I had to work it out twice and would rather nobody else did. The question about reading a syringe that I actually want…		2	22k	just now
Revisiting: Drawing from a pen cartridge with a syringe: how the risk profile changes Devices › Pens & autoinjectors dead volume missed dose storage subcutaneous injection Revisiting: Drawing from a pen cartridge with a syringe: how the risk profile changes Writing it up because I had to work it out twice and would rather nobody else did. Question about a metering device rather…		2	18k	6h
Fixed versus detachable needles: the trade-offs — does this still hold? Devices › Syringes & needles syringe units needle gauge & length dead volume subcutaneous injection Solved Fixed versus detachable needles: the trade-offs — does this still hold? I have a specific reason for asking rather than idle curiosity, and the context is below. Working notes on Fixed versus detachable…	+8	12	39k	15h
Why a pen's dose steps are fixed and what that costs you Devices › Pens & autoinjectors dead volume storage subcutaneous injection missed dose Solved The question in the title: Why a pen's dose steps are fixed and what that costs you I will give what I have already checked below so nobody repeats it. A question about a device rather than about a compound,…		4	2.5k	23h
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. A question about reading U-100 graduations that I think has a definite…	+35	41	2k	1d
Coming back to: Why I now write the concentration on the vial in marker Practice › Reconstitution reconstitution syringe units bacteriostatic water worked example The question in the title: Why I now write the concentration on the vial in marker I will give what I have already checked below so nobody repeats it. Writing this out with the numbers in it, because…	+8	12	4.3k	1d
How much of the diluent volume the powder itself displaces Practice › Reconstitution concentration maths bacteriostatic water dead volume worked example Asking directly, because I could not find a straight answer: How much of the diluent volume the powder itself displaces Writing this out with the numbers in it, because "roughly" is how these go wrong. Vial:…		2	1.8k	1d
Priming a pen and whether the primed volume is wasted Devices › Pens & autoinjectors storage missed dose dead volume Solved Wiki Priming a pen and whether the primed volume is wasted Writing it up because I had to work it out twice and would rather nobody else did. I have spent a fortnight trying to pin priming a pen down and I want to…	+19	23	1.3k	2d
0.3 mL versus 0.5 mL versus 1 mL barrels: resolution matters Devices › Syringes & needles syringe units subcutaneous injection needle gauge & length dead volume Wiki 0.3 mL versus 0.5 mL versus 1 mL barrels: resolution matters — setting out what I have, and where I think it stops being reliable. A follow-up question about 0.3 ml versus 0.5 ml that I did not know to ask…	+104	114	6k	6d
Reading a syringe in poor light, and how to avoid needing to — what changed since Devices › Syringes & needles dead volume subcutaneous injection syringe units needle gauge & length Posting this under the heading it deserves: Reading a syringe in poor light, and how to avoid needing to — what changed since Everything below is what sits behind that. What changes if the standard account of…	+3	7	27k	27d
[2026 update] A vial that will not fully dissolve: what to check and in what order Practice › Reconstitution concentration maths dead volume bacteriostatic water syringe units Solved Posting this under the heading it deserves: A vial that will not fully dissolve: what to check and in what order Everything below is what sits behind that. Practical question with the units stated, because I…	+114	128	20k	1mo
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
Reading U-100 graduations, with a conversion table — what changed since Devices › Syringes & needles worked example dead volume syringe units subcutaneous injection Reading U-100 graduations, with a conversion table — what changed since Writing it up because I had to work it out twice and would rather nobody else did. What changes if the standard account of Reading U-100…		2	10k	2mo
[2026 update] 0.3 mL versus 0.5 mL versus 1 mL barrels: resolution matters Devices › Syringes & needles dead volume needle gauge & length subcutaneous injection Solved On the subject in the title: 0.3 mL versus 0.5 mL versus 1 mL barrels: resolution matters Working notes rather than a conclusion. A follow-up question about 0.3 ml versus 0.5 ml that I did not know to ask the…	+108	124	27k	2mo
Foaming during reconstitution and whether it matters — the long version Practice › Reconstitution reconstitution bacteriostatic water worked example concentration maths Foaming during reconstitution and whether it matters — the long version — setting out what I have, and where I think it stops being reliable. A narrow question about Foaming during reconstitution,…	+100	117	6k	3mo
Converting between mg/mL and units per dose, both directions — the long version Practice › Reconstitution reconstitution worked example syringe units dead volume Converting between mg/mL and units per dose, both directions — the long version Writing it up because I had to work it out twice and would rather nobody else did. Practical question with the units stated,…	+110	132	1.7k	3mo
Reading U-100 graduations, with a conversion table — one year on Devices › Syringes & needles syringe units needle gauge & length worked example subcutaneous injection Reading U-100 graduations, with a conversion table — one year on Writing it up because I had to work it out twice and would rather nobody else did. I would like to disagree carefully with the settled view on…	+3	7	662	4mo
About the Pens & autoinjectors category Devices › Pens & autoinjectors dead volume missed dose storage Pinned Wiki Pen mechanics, dose counters, priming, and what happens when a pen is used off its label. This post is a community wiki: any member at trust level 3 or above can edit it, and every edit is recorded with its…	+1	5	92	5mo
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. Something about dead volume across syringe does not reconcile and I would like a second…	+72	80	28k	5mo
Filter needles: when they help and what they cost you Devices › Syringes & needles needle gauge & length subcutaneous injection dead volume On the subject in the title: Filter needles: when they help and what they cost you Working notes rather than a conclusion. Trying to work out what would count as evidence on filter needles, before collecting…	+45	50	19k	5mo
Coming back to: Pen dose counters: what a click does and does not guarantee Devices › Pens & autoinjectors storage subcutaneous injection dead volume Pen dose counters: what a click does and does not guarantee — setting out what I have, and where I think it stops being reliable. Reading back through what has been written here about Pen dose counters, three…		4	105	5mo
Coming back to: Reconstitution volumes that produce round numbers, tabulated Practice › Reconstitution concentration maths syringe units bacteriostatic water dead volume On the subject in the title: Reconstitution volumes that produce round numbers, tabulated Working notes rather than a conclusion. Writing this out with the numbers in it, because "roughly" is how these go…		2	24k	6mo
A pen that felt like it delivered nothing: diagnosing it afterwards Devices › Pens & autoinjectors storage subcutaneous injection missed dose dead volume Solved On the subject in the title: A pen that felt like it delivered nothing: diagnosing it afterwards Working notes rather than a conclusion. Question about a metering device rather than about a syringe, because…	+35	39	584	6mo
Pen mechanics when the cartridge is nearly empty — does this still hold? Devices › Pens & autoinjectors storage subcutaneous injection missed dose dead volume Asking directly, because I could not find a straight answer: Pen mechanics when the cartridge is nearly empty — does this still hold? Pen mechanics — I have the observation and I do not trust my…	+37	47	61k	6mo
Why "add 2 mL" is not an instruction Practice › Reconstitution reconstitution worked example syringe units dead volume The question in the title: Why "add 2 mL" is not an instruction I will give what I have already checked below so nobody repeats it. Practical question with the units stated, because I have seen how quickly…	+23	27	3.5k	6mo
Follow-up: The decimal-point error, and the habit that catches it Practice › Reconstitution concentration maths bacteriostatic water dead volume reconstitution Closed On the subject in the title: The decimal-point error, and the habit that catches it Working notes rather than a conclusion. A follow-up question about decimal-point error that I did not know to ask the first…	+118	131	50k	7mo
Coming back to: Over-dilution: when your dose falls below one readable graduation Practice › Reconstitution worked example dead volume syringe units bacteriostatic water Over-dilution: when your dose falls below one readable graduation Writing it up because I had to work it out twice and would rather nobody else did. I have read the maintained page on this and I still have a…	+90	97	1.1k	7mo
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. A follow-up question about gauge and length selection that I did not…	+50	55	1.3k	8mo
Needle changes between doses on a reusable pen Devices › Pens & autoinjectors subcutaneous injection dead volume missed dose storage Posting this under the heading it deserves: Needle changes between doses on a reusable pen Everything below is what sits behind that. The question about needle changes between doses that I actually want…	+34	38	1.5k	10mo
A ten-fold dose error caught before injection Devices › Syringes & needles needle gauge & length worked example syringe units dead volume Closed A ten-fold dose error caught before injection — setting out what I have, and where I think it stops being reliable. Trying to work out what would count as evidence on ten-fold dose error caught, before…	+95	103	26k	10mo

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