Struggling With High Vial Pressure When Drawing Medication?

QueenMuntha

QueenMuntha

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When I try to draw my dose, the pressure inside the vial is incredibly hard to manage. Even after pushing in 2-3 times as much air as the mg amount I need, the resistance stays extremely high, which makes pulling the medication out a real struggle. On top of that, once I remove the needle, the pressure is still there and liquid shoots out of both the rubber stopper and the needle.

Does anyone have advice for this? Should I be injecting a huge amount of air?
 
That doesn't quite add up...

If you're pushing in more air than you described, the pressure inside should push the liquid into the syringe on its own, with barely any pulling needed. You definitely shouldn't be injecting 2-3 times as much air as the fluid you plan to draw. Maybe +10% at most.

A far more typical issue is a hard draw caused by vacuum, which happens when there isn't enough air going in to take the place of the fluid you're removing.

To fix either case, the simplest options are: after reconstituting, take the plunger out of the syringe so the pressure can equalize, or before reconstituting, pull extra air into the syringe along with your diluent/BAC. With either approach, you should end up injecting roughly the same volume of air as the fluid you're going to draw.

FWIW, a tough draw can also be made worse by very thin needles, such as 31G and 32G.
 
ZippityDooDah said:

That doesn't quite add up...

If you're pushing in more air than you described, the pressure inside should push the liquid into the syringe on its own, with barely any pulling needed. You definitely shouldn't be injecting 2-3 times as much air as the fluid you plan to draw. Maybe +10% at most.

A far more typical issue is a hard draw caused by vacuum, which happens when there isn't enough air going in to take the place of the fluid you're removing.

To fix either case, the simplest options are: after reconstituting, take the plunger out of the syringe so the pressure can equalize, or before reconstituting, pull extra air into the syringe along with your diluent/BAC. With either approach, you should end up injecting roughly the same volume of air as the fluid you're going to draw.

FWIW, a tough draw can also be made worse by very thin needles, such as 31G and 32G.
Click to expand...
For what it's worth, certain Nexa vials I've used have a strong vacuum, so I've needed to add a lot of air. When your draw is just 5 or 10 units, then roughly 2-3 times that amount should be enough to cancel out the vacuum. Using a 100 unit syringe, something in the 20-30 unit range seems appropriate.
 
ZippityDooDah said:

That doesn't quite add up...

If you're pushing in more air than you described, the pressure inside should push the liquid into the syringe on its own, with barely any pulling needed. You definitely shouldn't be injecting 2-3 times as much air as the fluid you plan to draw. Maybe +10% at most.

A far more typical issue is a hard draw caused by vacuum, which happens when there isn't enough air going in to take the place of the fluid you're removing.

To fix either case, the simplest options are: after reconstituting, take the plunger out of the syringe so the pressure can equalize, or before reconstituting, pull extra air into the syringe along with your diluent/BAC. With either approach, you should end up injecting roughly the same volume of air as the fluid you're going to draw.

FWIW, a tough draw can also be made worse by very thin needles, such as 31G and 32G.
Click to expand...
That matches my own suspicion. With a 30, things move a little sluggishly. Pulling the plunger out after the needle is already in the vial is a really useful suggestion—appreciate it.
 
Pull the plunger right out of the syringe first. Put the needle into the vial — that lets the pressure equalise. Then slide the plunger back in and you're sorted.
 
cldfront said:

ZippityDooDah said:

That doesn't quite add up...

If you're pushing in more air than you described, the pressure inside should push the liquid into the syringe on its own, with barely any pulling needed. You definitely shouldn't be injecting 2-3 times as much air as the fluid you plan to draw. Maybe +10% at most.

A far more typical issue is a hard draw caused by vacuum, which happens when there isn't enough air going in to take the place of the fluid you're removing.

To fix either case, the simplest options are: after reconstituting, take the plunger out of the syringe so the pressure can equalize, or before reconstituting, pull extra air into the syringe along with your diluent/BAC. With either approach, you should end up injecting roughly the same volume of air as the fluid you're going to draw.

FWIW, a tough draw can also be made worse by very thin needles, such as 31G and 32G.
Click to expand...
For what it's worth, certain Nexa vials I've used have a strong vacuum, so I've needed to add a lot of air. When your draw is just 5 or 10 units, then roughly 2-3 times that amount should be enough to cancel out the vacuum. Using a 100 unit syringe, something in the 20-30 unit range seems appropriate.
Click to expand...
After mixing fresh vials, I put in the bac water and then detach the needle so the pressure can balance out prior to pulling the dose. Still alive so far.
 
ZippityDooDah said:

That doesn't quite add up...

If you're pushing in more air than you described, the pressure inside should push the liquid into the syringe on its own, with barely any pulling needed. You definitely shouldn't be injecting 2-3 times as much air as the fluid you plan to draw. Maybe +10% at most.

A far more typical issue is a hard draw caused by vacuum, which happens when there isn't enough air going in to take the place of the fluid you're removing.

To fix either case, the simplest options are: after reconstituting, take the plunger out of the syringe so the pressure can equalize, or before reconstituting, pull extra air into the syringe along with your diluent/BAC. With either approach, you should end up injecting roughly the same volume of air as the fluid you're going to draw.

FWIW, a tough draw can also be made worse by very thin needles, such as 31G and 32G.
Click to expand...
Another option worth mentioning for those who haven't thought about it: instead of the combined insulin syringe and needle units, they could move to a 1ml luer lock syringe paired with hypodermic needles. Drawing becomes much simpler using a 25g, after which you swap over to the 30g hypo to inject. Needles stay sharp that way too. Just putting that idea out there.
 
MaineUser said:

Pull the plunger right out of the syringe first. Put the needle into the vial — that lets the pressure equalise. Then slide the plunger back in and you're sorted.
Click to expand...

This morning, my vial responded FABULOUSLY to this approach. The 3 ml syringe is what I reached for.

Huge gratitude to @MaineUser and @ZippityDooDah
 
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