I just wanted to get an opinion following a discussion that happened at work today. I am used to using a Vamp system with art lines and cvps. The facility that I am working at right now uses a traditional system with a 3 way stopcock. We had a discussion about how much waste you would draw off an art line for a 4kg baby and if you would return that waste. What would you do?
Feb 4, '10
I work in a NICU and we pull off about 2cc waste for any baby regardless of size (.5kg and up). I don't remember the name of our system but the art line has 3 connections, one to the baby, one to the maintinence fluid and one to a long coil of tubing and a syringe. We turn the stopcock off to the fluids and draw back with the syringe until the blood meets a marked line on the tubing, then we enter the a-line port to draw our sample, then the blood in the tubing is returned. The tubing/syringe have fluid in them and the syringe has to be replaced/refilled periodically depending on how often you are taking sample.
Feb 4, '10
hmm I guess thats the vamp system I just described! haha
Feb 4, '10
Thanks I appreciate the answer
. The 2ml number helps, some nurses were saying more and some less. I have worked mostly with older kids and we always draw 5-10 depending on the kid. The system that I am using now has no marking or indicator line on the tube, you have to add in your own stopcocks and basically create a vamp and then hook up your syringes when you do a draw. Definitely a change for someone who has always used a closed system.
Feb 4, '10
The answer to this very good question depends on the length of tubing between the patient and the stopcock. If the stopcock is attached to the end of a T-piece (extension set) then the dead space is only about 0.8 mL... 0.4 for the extension set and 0.4 for the stopcock. If you have the stopcock attached to a 12 inch pressure tubing extension set then the dead space is more like 3 mL. One sort of rule of thumb that can be helpful is to keep your discard syringe perpendicular to the floor and watch as the flush fluid and then the blood enters the syringe. When you see about 0.5 mL of what is obviously blood at the bottom of the syringe closest to your stopcock, you've probably got enough (likely between 1.5 and 2 mL). Remember to turn the stopcock off to everything (1/4 turn) so you don't accidentally contaminate your specimen with flush fluid. As for whether to return the discard or not, that's a unit specific thing, so check your unit P&P. I've worked on units where we didn't return any of it, no matter how much was drawn off, and others where we returned every drop we could. Where I work now, we do so many gases and other labs that we return as much as we can, except on ECLS patients.
The only caveat to this is if you're sending unfractionated heparin levels and are using heparin in your flush solution. Then you need to flush the stopcock and catheter with a minimum of 5 mL plain sterile NS, then withdraw at least 5 mL of blood then draw all the other labs, then the UNFH level, and return as much as possible.