Just wondering how full lab tubes really need to be. I usually try to get mine about halfway (unless it's a blue top), but the other day I saw a more experienced nurse sending off blood with hardly anything in the tube, and I really was expecting the lab to say it wasn't enough blood, but as far as I know they didn't, so now I'm just wondering how full they really have to be...
Yes, some tests require very little blood. I just prefer my tubes to be filled
at least halfway, in general.
I can look up the minimum required volume for specific tests on our lab's intranet, I try to get at least that much without too much extra.
I base it on what's ordered. If it's just a specific lyte you only need like a mL or two. If that. Blue and purple tops, I always fill completely. And if there is more then just a lyte or a BMP being tested from the same tube, I fill it to the top.
Hematology studies generally require very little blood, and as long as the sample is not clotted the lab dosen't really care much else about them. Chemistry will depend more on the patient and their condition. For example you will get far more serum out of a sample that has a HCT of 22 than 44. Calcium citrate tubes always have to be full, a couple of other tests need a full collection tube as well.
Some labs are very particular about how full they want their tubes regardless of what volume is needed, others are far less picky.
I just allow the blood to flow until the vacuum stops, which is what I would assume to be the preferred amount of blood in that tube. It also probably depends on how many tests they are performing on a particular tube.
Sometimes you just can't get enough blood so that nurse may have just put a little in each tube.
You just fill until the vacutainer stops filling. Some only need 1mL or 2, others need more. Are you putting more in?
I try to fill everything at least halfway, except my blue/red tops which have to be full all the way. But chemistries/CBCs/Lactics I get as much as I can into, try to at least hit the labels on the vials we use which is about .75 mL to get to. I know how it can be sometimes- some people are like trying to get blood from a rock. If I ever have someone who is SUPER hard to get blood from or who has a really crappy CBC for whatever reason I'll sometimes use pedi tubes. Those all only require 0.5 mL with the ones we use.
Quote from EllaBella1
If I ever have someone who is SUPER hard to get blood from or who has a really crappy CBC for whatever reason I'll sometimes use pedi tubes. Those all only require 0.5 mL with the ones we use.
You can still put just 0.5 ml in the regular big tubes if desired. Not that its wrong to use the pedi tubes, but lab sometimes will say they still prefer the big tubes because then they can spin them down on the machines.
I would contact your lab people. They usually like explaining that stuff and only they know what type of equipment they have. When we got new equipment recently we had to adjust how much we were collecting for various tests.
The lab told me to let the vacuum fill the tube--or just to the line for a microtainer. If you fill it too full, like forcing more blood than the vacuum wants, when they spin the tube, the top comes off and the blood goes all over the place. Not good.
It depends on the test. I've lost a vein a few times during a blood draw and before I toss the tube and try again I call the lab to see how much they need. I was shocked when the lab told me to go ahead and send over a tube that had just barely enough blood to cover the bottom of the tube for a CBC and they would let me know if it wasn't enough. A short time later they faxed me the results, so I guess it was enough. Then again I've had the lab reject a tube for an INR when it was just barely below the fill line. If you ever have any questions about how much blood you might need call your lab, they'll be more than happy to let you know.
Our lab likes to cancel every single test if it is not full. I understand for blue tops but it is so frustrating. Usually if they are a hard poke then we will write that on the req and ask them to please spin.
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