syringe measurements

Home Health Columnist / Guide · Nov 25, 2002

Try these:

understanding dead space in syringes--skip first two articles, not helpful

http://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=understanding+dead+space+in+syringes

REgistration required here:

Challenges in Pediatric Pharmacotherapy: Minimizing Medication ...

... prescribers should also have some understanding of this ... fluids to their pediatric

patients in syringes. ... or medications trapped in the dead space of tubing. ...

http://www.medscape.com/viewarticle/421220_5 - 36k

Giving Safe Injections--great review of vacinine administraion for kids

http://www.childrensvaccine.org/files/Giving_Safe_Inj_Eng.pdf

hope this helps.

NICU_Nurse, BSN, RN · Nov 25, 2002

I had a horrible time trying to look this up on the internet, so I can't give you a link. However, I'm almost positive that the dead space in a TB syringe varies from 0.01ml to 0.05ml, depending on the manufacturers. They have 'new' (as they call them) zero-dead space syringes as well, that have no more than 0.01ml dead space in them. You could read the manufacturer's insert on these items, I'm sure, to find out more, or they might have a number you could call. Could you call the distributor? I'm sure they would have that information.

KRVRN, BSN, RN · Nov 25, 2002

And don't forget that there can be a few 0.1mls in the length of a needle too.

Uh oh, I admitted that I use needles to draw up meds... we're supposed to be needleless...

boggle, ASN, RN · Nov 25, 2002

It was my understanding that modern syringes are callibrated to accomodate the dead space, that is, if it says 1cc on the barrel, that's how much enters the patient when you inject.

This sounds like a question for the syringe manufacturers, (B D. company and friends)

Nurse Sheila · Nov 25, 2002

I wonder if there really is dead space. When a syringe is filled, including the needle, the injection propels the measured amount, including what began in the needle; therefore, the amount left in the needle after injection wasn't necessary to give the full volume. If you change needles, and the needle is left empty, that would be your dead space. You can overcome this by filling the syringe, changing the needle, then depress the plunger to remove air and fill the needle.

KRVRN, BSN, RN · Nov 26, 2002

Actually, like Boggle said, I think syringes are supposed to be calibrated to account for the amount left in the tip.

My point with the needle is that sometimes I will use a needle to squirt a med out of the 1cc syringe the pharmacy sends it to us in and into a larger syringe so I can dilute it properly. If we're talking 0.06cc of med, ALL of the med would be in the needle, rather than the bigger syringe.

boggle, ASN, RN · Nov 26, 2002

krvrn, I think I see what you are getting at here. When it comes to such tiny volumes however, you switch to a TB or insulin type syringe with the microfine or 25 gauge needles. The lumen is extremely small, as is the diamater of the syringe, so exact callibrating of the med is possible.

Now if your pharmacy is sending you a 1 cc of med in anything larger than a 1cc syringe, and you only need 0.06 cc, your pharmacist needs a talking to!

You can withdraw med with a smaller syringe from a larger one, but it is a pain. Ask them to package it appropriately.

KRVRN, BSN, RN · Nov 26, 2002

Actually they send me my whole whopping 0.06cc in a 1cc syringe and I want to transfer it into a 3cc so I can dilute it to then give it. Drawing it out with a tuberculin needle is a good idea actually.

I usually just squirt it out with whatever needle I grab first... which is usually an 18-g 1.5 inch needle. 0.06cc gets lost in there. So I have to draw up so air, flick it and then squirt it out with the air behind it. BUT this doesn't account for dead space, so maybe I'm actually overdosing?