Tiny but hopefully useful

[DocAnna]

Hi Anna are syringes calibrated with the needle on or off as this would be critical for medical purposes.
I am guessing the ones for dispensing medicine (for children)are calibrated without syringes
Asking for a friend

It makes no difference as it's the expressed volume which is the difference between plunger position, so as long as the needle has been primed the dose is the same. These days we use filter needles to draw up the dose, then swap to the needle for injection, prime and inject. Or if there's a cannula or butterfly in place we don't use a needle at all - though it's important then to flush through as there's quite a lot of dead space, particularly with sub cut butterfly lines.

@The Baron yep, the needle hub contains the relevant drug.

Anyway... a bit off topic.

 

[RichardM]

Anyway... a bit off topic.

But interesting

 

[MashBag]

Does that mean the syringe needle is still full fluid rich which makes sense

Not if you rinse it out in the liquor?

But.... I use 15ml AMS. Does it matter at that volume when I test with pool strips?

Probably the same impact as a sparrow farting has on climate change?

 

[MashBag]

So you are completely losing any accuracy... there's about 0.2 to 0.4ml dead space in the syringe once fully closed, the markings on the syringe correspond to the expressed volume, not the volume in the syringe. If you pull such liquor back and rinse that way then that extra bit gets added in. I had this discussion many many years ago with a nurse on a neonatal unit when diluting medicines in special care baby unit, that you can't measure the amount in a 1ml syringe then dilute it in the same syringe. ( I should emphasise the person in question had not done this for a baby's dose - it was an explanation of why)

However, to be clear the accuracy doesn't matter that much. Right back to my original post, it's just a bit easier for me to weigh these rather than putting my fingers into the neck of a bottle of a caustic acid. I also want to be consistent about what I do.

With you and I do prefer weighing. But that has its own inaccuracy, because I am guessing the weight/ml of AMS..
I think it's about 1.3

 

[An Ankoù]

So you are completely losing any accuracy... there's about 0.2 to 0.4ml dead space in the syringe once fully closed, the markings on the syringe correspond to the expressed volume, not the volume in the syringe. If you pull such liquor back and rinse that way then that extra bit gets added in. I had this discussion many many years ago with a nurse on a neonatal unit when diluting medicines in special care baby unit, that you can't measure the amount in a 1ml syringe then dilute it in the same syringe. ( I should emphasise the person in question had not done this for a baby's dose - it was an explanation of why)

However, to be clear the accuracy doesn't matter that much. Right back to my original post, it's just a bit easier for me to weigh these rather than putting my fingers into the neck of a bottle of a caustic acid. I also want to be consistent about what I do.

There's no question that weighing is very much more accurate, but it's hard to teach an old dog to change its spots.
If I understand you correctly, the rinsings from the syringe should be discarded and not added back to the liquor. Thanks. I didn't know that.
As for weighing. I'd likely use the syringe to transfer from the bottle to the weighing vessel

 

[An Ankoù]

Probably the same impact as a sparrow farting has on climate change?

Yeah, you say that. Just look out of the window!

 

[MashBag]

Yeah, you say that. Just look out of the window!

It wasn't the sparrows