Waddaya Want? Blood????
Thursday, March 3rd, 2005I’ve been giving blood semi-regularly ever since college (14 years or so…), and I did so again yesterday. This time they had something new, however, called the ALYX system, and I thought it was really pretty amazing. This thing will save a lot of lives.
Normally, I give whole blood, which is extremely straightforward — they stick a tube in a vein, and your body pumps blood down the tube until the bag is full. For years there has been a different procedure wherein the donor donates platelets, which are just part of the blood and used in certain procedures. The give-and-take here is that whole blood has the red blood cells, which in medical terms are the most useful part of the blood, but platelet donors can give more. I’ve seen people donate platelets, and compared to whole blood donation it’s a major ordeal — you have two needles, one in each arm. The blood goes out one tube, into a big machine that uses a centrifuge to separate the platelets out, and then uses the other tube to pump the remainder back in the other arm. It takes about two hours, (whole blood takes about 15-20 minutes) and because the blood being separated cools down when it’s in the machine, you have room-temperature blood being pumped back into you for that two hours, which cools down the body. A man sitting across from me yesterday undergoing this was covered with a heating pad to alleviate this.
The ALYX system is similar in concept to the platelet donation, but more advanced and much easier (and only takes about 30 minutes). They use one needle, and it’s actually a smaller needle than with whole blood donation, so it’s less of a jab when the stick it in (and after a minute or so, I literally could not feel that there was a needle in my arm!). The tube goes to a machine, which draws some blood out, separates out the red blood cells, and then pumps the remainder, along with some saline, back in through the same tube. This goes through about five out/in cycles, (because drawing that much blood out of you without putting some back would be really bad for the donor), the end result of which is that I have given the equivalent of two pints of the most important part of the blood — twice as much as with whole blood donation.
There were a few oddities relative to whole blood donation. Every once in a while, during a draw cycle, it would suddenly feel as though the needle was vibrating! This was not painful in the least, mind you, but it was weird — it felt like a cel phone on silent vibrate, but inside my arm. I asked the nurse and she explained it thus: With whole blood, you body and gravity is doing the work of drawing the blood out and into the bag. With this system the machine is actually creating a suction to draw it out, and sometimes the vein closes and pinches against the end of the needle. The machine detects that this has happened and immediately stops drawing, and the vibrating that I’m feeling is my vein popping back open.
The other difference was that after a while, when it was putting blood back in, my arm would feel cold — this increased slowly as each successive cycle went by. For the most part it felt sort of like a cold compress in my bicep. (As with platelet donation, this was being caused by cooled blood and room-temperature saline being pumped into me). During the last return cycle, it extended from my elbow up to my shoulder, and my body responded by shivering slightly. Just as the whole process was finishing, I started shivering all over, and felt very chilly. There were no other issues and I just went and put my jacket on and warmed back up (though some hot tea would not have been turned down!) The unusual part was that I had been chilled from the inside, and the feeling was more persistent than if I had gone outside for a couple minutes and gotten cold that way.
Overall, I would certainly do this procedure again the next time I donate. The needle is significantly more comfortable than that used with a normal whole blood donation (though that may be due to that fact that, according to the nurse, I have narrow veins), and the only difficulty was the chill at the end — the nurse said mine were a lot stronger than with most people. I’ll just have to request one of those heating pads and I should be fine.
(Disclaimer: I don’t own stock in the company [NYSE: BAX], but if they make more stuff this good, I may just consider buying it.)



