Today I went to donate blood for the first time. I don’t know what type I am, but evidently they’re hard up for O and I’ve got to be A or O, plus the reason I didn’t used to do it is that I was too thin, which, um, no longer applies. Anyway, we went through all the preliminaries, the nurse took my temperature and blood pressure, and then stuck me for the hemoglobin test. She said I had to be 12.5 to donate. It came up 12.3, and she said somebody else could try again (no idea why the same nurse couldn’t do it) and that it was quite likely to be high enough the second go round, and the second stick came up 13.
Which sucked ass, by the way - I hate those finger stick things way more than the big scary needle. Why on earth do they do it on your sensitive fingers, anyway?
So my question is, why the hell did it give a different result? My theory was that maybe the machine isn’t as accurate as its display? In other words, that it isn’t really a significant digit? Surely my hemoglobin didn’t change, right?
By the way, I totally overdid it afterwards moving some boxes around and started bleeding again - not all that much blood, but I got it all over my shirt and had to ask the boyfriend for a hand rewrapping it. The sight of the blood literally almost made him pass out - I’ve been with the guy five years and had no idea he was so blood-squeamish! Seriously, this was after I’d cleaned my arm up - just some stains on my shirt. You learn something new every day.
I’m curious about this, too, because I have to have it done just about every freakin’ time I donate. When I have it done, they take the 2nd stick from the other hand, not a different finger on the first hand they stuck.
I’ve had the second stick come up high enough. I’ve had it be lower than the first reading.
And I REALLY wanna know what’s up with the Bad Juju Nurse thing - why couldn’t the first nurse try again? Why a different person? Does iron like the second lady better? Once she got it, the first lady came back in to finish the paperwork.
For this part, I think it has to do with paperwork/record keeping/following a protocol more than any “Bad Nurse Juju” thing. Once something as important as hemoglobin (for blood donation purposes) gets logged into the registry, they don’t want the same person to change it, but would rather have someone else do that. Perhaps an insurance against falsifying levels?
That does make sense, just in the environment of very detailed record-keeping they do - there seemed to be a lot of insurance against mislabeling my blood, I noticed, for example. Everywhere I went I had to reverify that yes, that’s my name and SSN.
Wouldn’t any test like this only take a small sample, and extrapolate it to figure out the actual count? I would then guess that the levels are not even throughout the blood, and thus it is possible that different tests would give different results.
I haven’t learned about this test yet, so this is conjecture. It may be that the sample was too small the first time, or the blood waited too long before it was tested. Both of those errors will screw up a lot of blood labwork, although, I repeat, I know next to nothing about this specific testing procedure. I do know that some people have weird blood that, when it’s chilled, tests low for hemoglobin, but when warm, tests correctly. But I doubt they’re chilling your blood before this test in that situation.
And, while it’s not entirely comparable, I know that it’s common for nurses who are having difficulty with a blood draw or IV placement to try only twice, and then let someone else have a crack at it, if someone else is available. This is for a couple of reasons. First, because when you flub it, it’s natural to get nervous. When you get nervous, your hands shake, and shaking hands do NOT help you get into a vein! Secondly, the client starts getting nervous, agitated, upset or otherwise negative about the whole thing, and that doesn’t help the situation, either! It’s mentally and emotionally easier on both the nurse and the patient to bring another clear head and fresh face into the room, so client confidence can be restored.
Regarding the machine… the various things that others have told here (low/cold temperature, not so accurate machine, uneven hemoglobin distribution) are what I’ve been told when I don’t pass the test in one finger but do with the other one. They’ve also done all sorts of things to make the second test come up, such as warming it, taking it from a different height, and bleeding it longer before collecting the sample.
All these helps when the differences are a few decimal points. When you’re supposed to be 12.5 and it comes back 10 (or 8)… unlikely the second try is going to help.
And btw, many of those that work in blood donation centers are NOT nurses.
If that includes people that have never gone to any sort of nursing school, then yes.
I don’t doubt some of them are nurses, but there are also medical technologists and phlebotomists (the nice term for those that stick you with needles). They may have a degree in something else (biology). But many of the ones I do know are definitely not nurses, nor plan to attend in the near future.
While I don’t doubt that most nurses have the skills to work in such environment, it would be limited use of their total training. Viceversa, other groups are awesome with those skills, but know very little of the nursing field outside that specialty.
The quick tests are not as accurate as a proper lab machine; they’re basically screening at that point to catch people who shouldn’t be donating due to low hemoglobin; they’re not looking for a precise number. As people have pointed out, the only question arises with people on the bubble; if you’re an obvious fail, you get to go home and eat some liver. (Or go see your doctor and find out why your hemoglobin is low.)
You guys must have more advanced blood donation centers than 'round here. Every place I’ve ever been to uses Packed Cell Volume instead of true hematocrit, since the equipment is cheaper.
Up until the last three or four years, they didn’t use the hematocrit, they just droped your blood in that that blue liquid and hoped it sank (I don’t know whta test that was called.) If that failed, then I know they’d take a slightly larger sample and so “something” with it, maybe that was the hematocrit or packed cell volume…it always took a little while, IIRC (I only had to have that once, I’m usually very good. I donated last Tuesday and was a 16.5…I average maybe a 15.)
Im guessing they switched when the technology got far enough along that they can be small and cheap, yet accurate enough.
By the way, what’s up with this crazy-ass bruise I ended up with? There’s a big circular black and blue mark around the needle mark, and then it has a tail going up my arm - not the way the needle went (that was straight) but diagonally towards the ground side of my upper arm. When I overdid it and started it bleeding again did the blood under the skin follow the vein or something? It’s really quite colorful and spectacular. (The boyfriend can’t even look at it.)
If the bruise wasn’t there right after your donation, it is indeed due to you reopening the needle stick. The opening in the vein probably let out more blood than the opening in the skin could release, so some of it backed up under the skin. The diagonal part is probably from the way the muscles go together there.
However, I’d watch it. If it starts to hurt or grows at all, get it checked out. At the very least, call that phone number they gave you after your donation and talk to them about it.
(Or go see your doctor and find out why your hemoglobin is low.)