Finally, I'm getting to this segment of my clinical rotations. It's been busy with the weekly tests and unexpected management homework, but with this "winter vacation," i should be able to update on my time in the blood bank, and n'er spare the details.
i spent 3 weeks at Carter Blood Care in Hurst (or Bedford), Texas. It is the major blood bank for Fort Worth and Dallas and everything in between. Recently they acquired a blood bank in Tyler, which has a strong HLA department and is a core HLA lab (to my recollection, my mind is fuzzy on this matter at the moment). I stayed in the Reference and Transfusion Lab, where essentially the lab is. It is comprised of med techs that are always there. They will perform the lab testing to determine a person's blood type and presence of antibodies in order to find and send out bags of blood.
"compatible blood" is what people hear when they think of transfusions, and that's what we do. usually, a doctor will order an Antibody screen and crossmatch. this is usually for surgery. a med tech will then receive the patient's blood sample and centrifuge it into two parts: serum (or plasma) and packed red blood cells (RBCs). serum is the fluid in which your red blood cells flow through and contains anything else that may be flowing through your veins (such as antibodies).
a patient's serum is used to determine what antibodies they have and indirectly determine what antigens they don't have. the word antibody is said a lot in the news and media, making people think that it's a supercure that is within our blood, but it's just a half truth. it's actually a small protein that binds to something foreign to your body. Your body makes these all the time and they are specific to many foreign substances that you encounter. for instance, whenever you are vaccinated, you're actually infected with a disease. the disease is actually weak or dead and cells in your body will attack it. As a result, your body will make antibodies to that disease so that body will respond to any re-infection.
a patient's cells are used to determine what is on your cells and group you into a "type." like type A, B, AB, or O. what you may not know is these types are determined by what sugars are on the surface of your red blood cells. the type O sugars are the base sugars for RBCs, so A, B, and AB types will also have O sugars, but with additional sugars on top. this is the reason why O blood is the universal blood type. the other types have O sugars and do not make any antibodies against type O blood. on the other hand, type O serum has antibodies to A and B type sugars. so only type O blood can accept O blood. at the same time, type A will have antibodies against B type blood and vise versa. AB blood types do not have any antibodies against A, B or O because they have all three sugars on their RBCs.
now, what does positive or negative mean? it's actually another sugar that is on the RBC in a group/family/system called the Rhesus system (Rh system). positive means you have it and negative means you don't. if you don't have it, then that means you can make an Rh antibody which is a very quick to acting antibody. This because a big problem in the blood bank because majority of the world is Rh positive. so in order to stop Rh negative people from making these antibodies, the hospitals will make sure to give the patients Negative blood.
though there are different ways other than blood transfusions can a person get exposed to blood and developing an antibody. an example is sharing needles or an accidental stick, or through a pregnancy (baby blood will mix with the mother's during delivery). basically your body is exposed to a foreign blood and your body will then identify the foreign substance and create an antibody to it.
so now you have a general idea on what a blood bank does and what the meaning is behind blood types. now you think A, B, AB, and O types is just so little and easy to remember, why need for techs to do this? well, the human red blood cell contains over different antigens on cell membrane, making the serum capable of making a bunch of antibodies whenever it is exposed.
sometimes patients will come into the emergency room and will need some blood. later, techs will dicover that the person has antibodies to a couple of different types. well, it is possible that the blood will be destroyed by the patient and they will lose blood. though, because of techs, they will ID those antibodies and find blood in the blood bank that does not have those types and we call that compatible blood.
the blood bank makes different products, including red cells (blood), plasma, platelets and other miscellaneous products for specific procedures or treatments. platelets are the cells in your body that clots wounds and assists with healing. they only last for 5 days. any platelet that doesn't get used for 5 days can be sold to a cosmetic company to create makeup. that's right ladies, some of the makeup you are using is probably made from a person's blood.
though, you have nothing to worry about, because diseases can not be tranmitted by this way.
plasma is sometimes used for people that lose fluid. so they need a medium for the blood to flow through. AB plasma contains no A or B antibodies. in terms of plasma, the less antibodies the better.
well, that's a generally look into the blood bank. if you have any questions, i'm always a comment away. i feel very satisfied with my experience and it will be my choice to go into the blood banking specialty. it has instant-gratification because you work about 30 mins to an hour and a half on a patient in order to discover a patient's complete type and antibody screen.
i've also become a big advocate for donating blood. blood is needed all the time, but it expires. so instead of donating at big drives, you should donate periodically through out the year. it is important that a blood bank is fully stocked all year round and not only during one season. blood can last up to 42 days max without freezing and the older a bag of blood is, the less chance of it will be healthy for the patient.
plasma or platelet donors are also needed as well. so if you have a high platelet count or want to donate plasma, you should take that opportunity too. plus, at the end of every donation, they feed you with a snack and juice. :)