Blood Type : LUSENET : ER Discussions : One Thread

In "All In The Family", Benton asked for type specific blood for Carter when he found O neg on the stand (although Carter turned out to be O neg anyway). But why would type specific blood make a difference? Does it improve the outcome for the patient? Or does it let you save stocks of O neg, which must be the most useful type, since anyone can have it. Just curious.

-- Steph (, July 01, 2000


I'm not sure but I expect that it is better for the patient giving Benton's angry reaction when he thinks that Carter isn't getting type specific blood. Curiously we are told about Carter's blood type earlier in this season too, when due to a shortage Carter has to donate some Oneg for a patient, twice in one season...a future storyline perhaps?!

-- mags (, July 01, 2000.

Yes, type specific is preferable, because the blood involves other lesser "antigens" or types besides A, B, AB and O and Rh positive or negative. These lesser antigens may be characteristic or common to certain blood types, so it is less likely that a patient with A blood will react to a unit of A blood, since most people with A blood are likely to have many of the lesser antigens in common too.

In a normal type and crossmatch test, the lab will screen your blood against the unit you're getting to check for reactions to these lesser antigens, but in an emergency where the patient needs the blood sooner than the time constraints of a full crossmatch test would allow, they try to at least screen for and give type-specific blood (i.e., A neg blood to an A neg patient), to reduce the possibility of a reaction to one of the lesser antigens. If they don't have time for that, O negative, the "universal donor type," is given because the O blood will not cause a reaction with A, B or AB type patients (O blood is simply blood that does not have either the A or B antigen), and negative blood will not cause a reaction in an Rh positive patient. That's why when they are prepping for a bad trauma on ER, you often hear them order 4 units of O neg - if they have to, they can give the O neg to a trauma patient until they can test for his actual blood type. The O neg blood may still contain lesser antigens that are uncommon to an A, B or AB patients. This may cause a few patients to react immediately, and other patients may develop antibodies and have problems down the road with later transfusions, but if the level of blood loss is life threatening, the risk of a bad reaction is significantly outweighed by the need for immediate transfusion.

Hope this makes sense ...

-- Beth (, July 01, 2000.

I have to correct some of the points that the previous contributor (Beth) had to say about blood group antigens and antibodies. The lesser antigens on red blood cells are not more common to any A, B, O blood groups. THAT is not the reason that is is better to go with type specific blood. The reason for that is that even when you give a unit of packed cells (rbcs with the plasma taken off of the unit of blood) there is still some lingering plasma in the unit of blood that is given. If- for example an A-neg person receives several units of O neg packed cells, the antibodies in the plasma of the O neg include anti-A. This anti-A attacks the patients own cells and causes them to pop. This is called intravascular hemolysis. It can negate some of the good that the transfusion is trying to do in the first place. True there are lesser antigens on rbcs and they can cause death if the person has an antibody to that antigen. (But only if the person has had a previous transfusion or pregnancy) These lesser antigens are not more prevalent in one ABO group than another. The other reason to give type specific- and in my opinion it is VERY important- is that if you use up all the O neg on the emergency patients that you do not get a specific type on- say on all the A pos car wrecks and the B neg knife wounds-- and then you have a gunshot wound come in that is O neg and you don't have anymore O neg- then your O neg patient will bleed to death because that is the ONLY blood he can receive. For this reason it is good to at least get type specific if at all possible. Sometimes ER makes it seem like there is an endless supply of O neg---NOT TRUE. And anybody out there who cares to know- if your loved one needs blood in an emergency situation, you better hope that someone has had the good will to give ahead of time, because at the time of the emergency it is too late for your loved one to get your blood. Processing takes about 48 hours from the time of the donation. ----Sorry for the length----

-- joan(a former blood bank tech) (, July 01, 2000.

Thanks Joan, or correcting my misinformation - you are correct of course. I am also a former medical technologist (I left when the health care industry tanked in the early 90's), but Blood Bank was not my specialty. I was responding from distant memory from my days in training almost 20 years ago- an impulse I promise to resist in the future! Apologies to everyone reading my earlier post.

Thanks, too, to Joan for urging everyone to consider donating blood - it is one of the easiest ways for you to help your fellow man, woman or child, and is well worth the small amount of time involved. Donation can be done on your schedule, too - not just when there are blood drives in your workplace. End of public service announcement :-)

-- Beth (, July 01, 2000.

Don't you have to weigh a certain amount though? I once was told that you had to weigh at least 116 lbs.

-- Tracy (, July 01, 2000.

There's a weight minimum and an age minumum. Also, the person can't have had any piercings or tattoos for the past six months. I can't ever give blood because I take anti-coagulants. I would if I could-- really.

-- Carin Haseltine (, July 01, 2000.

I think I can answer the weight question.

When I was in high school (about 15 years ago-damn I'm old!)We had a blood drive. I couldn't donate because I was underweight. I was told I had to weigh at least 110 pounds. This is unfortunately not the case now!

-- S.Trelles (, July 02, 2000.

For those of you who want to donate but you might tip the scales a little on the low side, if you are not a minor you would probably be eligible to donate a half a unit. These small units are often needed for the premies or newborns since they could never use an entire adult unit of blood. There are many reasons that people cannot give blood and the list is too long to go into on this post. **The more common your blood type, the more your type is needed. An interesting tidbit: If you or one of your loved ones needs a transfusion, the best donor is an anonymous donor. The reason for this is ---- if the person that you know that you might ask to give so that his/her blood can be given to your loved one- if that person has a lifestyle that everyone does not know about- they are not likely to want to divulge this to everyone. They would just give and not disclose that they might be at a high risk to give the recipient an infectious disease. If not put on the spot- this person would stay out of the donor population and not put anyone at risk. Thus, rely on the good samaritan that gives because they know that they are a totally safe donor. EX: You have a child that needs to receive blood so you ask your cousin to give because she knows that she is A pos- the same as your child. You think this is a safe bet. Do you think that she would tell you that she has slept with three men in the last six months and that she is not sure of the HIV status of all three of these men? Probably not. So your child receives blood that is contaminated because the donor does not want to tell the family about all her possible encounters with possible disease. Scary but true!

-- joan (, July 02, 2000.

I was also told that I had to be over 110 lbs. at a college blood drive my freshman year 2 years ago. I thought it was rather silly since I'm not THAT much under 110.

-- JLS (, July 02, 2000.

I remember reading somewhere that the most in demand bloodtype is Oneg because it is the only one that can be recieved by other blood types thus making it in demand, but only approx 6% of the population have and can donate it. (I could be wrong)

-- mags (, July 02, 2000.

While O neg is the rarest and the only one that can be given if the recipient has not been typed yet, O pos is still the type that is in the greatest demand. Call your local Red Cross or the equivalent in your town and ask them. O pos + A pos people make up about 60% of the population. (That % may be a little off, but it is close) Most ERs get a type before they start pumping blood into the patient. They have to or they would run out of O neg every day. Generally speaking, if the person cannot live for the few minutes that it takes to spin an ABO and Rh type on them, their chances are slim to ever see the light of the next day. Not always but generally speaking.

-- joan (, July 02, 2000.

I've given blood for years and a few years ago switched to donating takes a lot longer (about 2 1/2 hours in total) but you can give more often because the blood is taken out of what arm, the platelets removed as it passes (in a sterile environment) through a machine, then the red cells and liquids are returned in your other arm. They can also remove plasma. Platelets are needed for sick people with immunity issues, such as cancer patients undergoing chemo, etc. When you give whole blood you can only give every 56 days (something like that). I gave about once a month with platelets (I moved a little while back and haven't established myself here with the ARC) but think I could have given about every two weeks or maybe even more often. The only problem is there's not much you can do when you give platelets...they had TV's where I lived but you shared them and were at the whim of everyone could bring a tape and listen to it through headphones. Of course you can't read because you can't move your arms. I met some interesting employees and other donors there though, many giving for specific friends and family members (they gave very often). Just thought I'd share.

-- Diana (, July 02, 2000.

Julianna donates blood regularly because she's "A positive and they need it".

-- JLS (, July 02, 2000.

You can also donate white blood cells for the same kind of patient that needs the platelet transfusions. Many leukemia patients need WBC transfusions. The one epi where TPTB had Carter donate his O neg by sitting on a chair in one of the treatment rooms without one single question about his donor status and they just jabbed his arm while he sat on the stool--It was a very irresponsible way for the writers to handle the situation of a blood shortage. It gives everyone the wrong idea about how the critical situation can be handled.

-- joan (, July 04, 2000.

Amen, Joan - I noticed that too! I also hate the way they all go around touching everything (door knobs, telephones, each other) with visibly bloody gloves. Ick.

-- Beth (, July 04, 2000.

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