OT - /Injections

(a) not if what is being stabbed is sterile and designed for it (b) that's not how they do it anyway AFAIK Normally the needle is fitted to an already filled syringe which is discarded after used along with the needle

And you don't think this has been thought about? Given the billions of injections given every year?

The top of multi-dose vials has a soft centre, which will not damage the needle. Everything starts out sterile. Maintaining sterility during a vaccination session is down to good clinical practice.

nightjar snipped-for-privacy@bignell.me.uk> wrote in news: snipped-for-privacy@giganews.com:

Thanks.

"Dave Plowman (News)" snipped-for-privacy@davenoise.co.uk> wrote in news: snipped-for-privacy@davenoise.co.uk:

Of course - trying to understand it.

Not if you clean off the rust from the needle first.

I assume that you have not seen how things like the flu jab are administered.

The vial has a self sealing "soft" top designed to be penetrated with the needle - so it won't damage the needle. Both it and the needle start out sterile, and the needle is a single use item, so is discarded after use. So the only risk is if you contaminate the top of the vial before taking the next does out (there are only typically 5 doses per vial for the COVID19 vaccine)

If you had been paying attention you would read the bit about being able to get 6 doses out of a vial, with care, rather than the 5 that were being extracted leaving unnecessary wastage.

Though in the case of Covid vaccine they are delivering in in sterile vials of about 8 septum sealed doses and using discrete syringes. I guess it was the fastest way for them to roll it out.

You can't go to a much bigger volume vial than that or you do need to worry about cross contamination of the later doses.

Eh? to what do you refer exactly? Brian

Many people who inject themselves (specifically with B12), often use two needles. One to draw up, another to inject.

Several reasons - lengths required - one to reach bottom of ampoule, the other right for the mode of injection, possibility of damage blunting the needle. And that is with single-dose ampoules so, effectively, no cross-infection likely.

In the past, multi-injection vials held about 10 injections worth.

A small amount of thiomersal mixed as one of the ingredients, is what keeps seasonal flu vaccine "fresh". Thiomersal is a mercury compound, which has some sort of antibacterial action. There would be a small quantity, around micrograms of the stuff, in the vial.

When the needle pierces the septum, it drags bacteria from the outside world into the vial. While the vial is wiped with a cotton swab dipped in alcohol, a microbiologist would tell you the container is compromised. And that's why a preservative is used. It's a "just in case". You never know how clumsy the operator is, in terms of hygiene issues.

Some of the vaccines, the ones stored at extremely low temp, are stored dry. To reconstitute, the first stab through the septum deposits saline solution. Then the vial needs to be agitated, until a uniform solution is made from it. Then you can draw doses with additional stabs through the septum. Typically, for lab work, you don't "shake" containers like that. There's a nice little machine that gives a reproducible effect, which can be used (but those are designed for tiny test tubes, not vials). You're also taught in the lab, the two-finger technique for agitating without shaking. You can't be doing that too many times though, without getting careless. That's what I found. If agitation is used for these injections, a machine should really be used, because it doesn't get tired.

Since the injections given from the COVID vaccine vial, are given over something like five hours or less, this gives little time for bacterial reproduction. And then you can dispense with thiomersal and it's not needed. When giving seasonal flu, the vial can be in the fridge, and used from one day to the next, for much longer periods of time.

Single-shot delivery of seasonal flu vaccines, doesn't need thiomersal, but is also less common. For seasonal flu, they bought something like 20,000 single-shot servings. Presumably these are for usage on infants (people just over the minimum age).

As for damaging the needle, how many times have you seen one of these tiny modern needles jam up ? They never seem to get septum rubber into the needle. That may have been happening decades ago. (The needles they have today, are much nicer than ones decades ago.)

Paul

Rust ?!?

These are single-use needles in sterile packaging.

There are many situations where needles are used, including a quite impressive range of sizes. I'm sure some are still reusable and have to be autoclaved between uses. For the ones we would normally be allowed to see, those are the single use ones. Only if you were in an operating room, would you get to see some of the more impressive ones (like devices for spinal fluid). I sure hope the doctor doesn't show you this, before your procedure...

Paul

I saw them doing the epidural for SWMBO (I was right beside them). That was pretty impressive.

"Inactivated influenza vaccines for intramuscular administration are supplied as suspensions in pre-filled syringes. They should be shaken well before they are administered."[1]

That'll apply to the bulk of the 30 million in the UK offered free vaccination this year as only children over 2 are routinely given a nasal spray. So only about 3 orders of magnitude difference from whoever "they" are.

Hmm. I had an epidural socket fitted during treatment for smashed ribs and partially collapsed lung. Took a senior anaesthetist to find the gap as they were going high up where the arm nerves branch off. He sat me on the side of a bed and got me leaning forward as far as I could manage. Whatever the two part mix was, critical care cocked up the next day as the pump was not properly programmed for the pack sizes used and I got a dose of the opioid without the balancer. Rather concerning hearing the blood circulation!

When I'm quiet I can hear my blood circulating, I'd be more concerned if I *couldn't* hear it! :-)

Humour. :-)

They are also made from 304 stainless steel these days.

When I made them, we used tubing in sizes from 30swg (0.3mm) to 10swg (3.2mm) as standard and sometimes larger. Contraceptive implant needles needed to have a 5mm bore, for example.

Only the really expensive or complicated instruments. The vCJD outbreak ended a lot of reuse as autoclaving alone doesn't remove the protein from stainless steel.

:-) 14 years ago now but rather frightening at the time. Any movement sounded like a loud creaky armchair. I squawked and a junior doctor took it out. Detail a bit hazy but something like they had fitted a 500cc pack of Novocaine? and the machine was expecting 200cc so stopped pumping from that container. They changed me to a Morphine pump which I rarely used.