Can a transfusion of the wrong blood type hurt you? Kill you? Or does it just not do what it’s supposed to do?
All of the above. Your immune system attacks the red blood cells in the donor blood if it’s incompatible.
Implicit’s answer is why there are important safeguards that are supposed to be in place when blood is transfused. When blood is picked up from the blood bank, both the lab tech and the nurse receiving the blood are supposed to independently confirm the name, ID numbers and blood type. At the patient’s bedside, two nurses independently cross-check the patient name, ID band, blood type, ID numbers on the blood bag itself. I have a few patients who have to get frequent transfusions and I encourage them to look at the blood bag and make sure their name and their blood type is there. It can never hurt to have one more safeguard!
The fatal reactions that occur from “mismatched” blood are virtually all due to ABO blood group incompatibility. More common, but usually much less severe, are reactions due to incompatibility of minor blood group antigens. This type of incompatibility is checked for before transfusing blood, but some reactions will occur regardless (e.g. if the person had only a very low quantity of antibody against the donor blood before the transfusion, it may not have been sufficient to cause a positive test. However, after the blood has been transfused, it serves to “remind” and then stimulate the recipient’s immune system to make more antibody against the transfused cells. The test would then be positive, but it is now too late).
Another cause of severe transfusion reactions occurs when the recipient is one of the rare individuals who lack all antibodies of the IGA type and then receives blood containing such antibodies (which are present in virtually everyone else). When that happens, the recipient can develop a severe allergic reaction that can even be fatal. This phenomenon is briefly discussed here. Despite the potential for this type of problem, AFAIK, IGA deficiency is not (routinely) checked for in people before they receive a transfusion.
Reading things like that makes me sooo glad I’m AB-positive, the universal receiver. Bring your antibodies on, I already got a whole set! knock wood that I’ll never need a transfusion
[slight thread hijack]
I have a not entirely unrelated question here if I may.
Imagine a triage scenario such as a battlefield or major disaster. A severely injured person is brought in and he is right on the cusp of being able to be saved if he goes into the operating room NOW or being one of the unlucky few who get a shot for the pain and a quiet place to rest while they die. Is having enough of the right kind of blood a valid question the medical staff might consider in making the determination?
[/slight thread hijack]
Yes. Considering my current resources, resources expected to be delivered and on what schedule and the patient’s chances of survival are all things we’re trained to take into account when performing triage in Mass Trauma or Disaster Scenarios. If I don’t have enough of the right kind of blood (assuming the patient is going to need typed blood products and can’t use, say, plasma or synthetic blood)…there’s no sense using the other resources (surgeon, circulating nurse, scrub nurse, anesthesiologist, assistants, oxygen, medications, saline, etc., not to mention what typed blood I have) that are needed by people I can likely save.
Not having the right kind of blood might be a triage consideration, yes. But most hospitals and armies try to have a lot of O-negative blood on hand, to fill in when the right kind of blood isn’t available. Or when there’s not enough time to check.
O-neg isn’t a perfect match, but it’s less likely to cause a reaction. Those of us with O-neg blood get nagged by blood banks regularly, once they have our phone numbers.
When I worked in the OR in Bagram, Afghanistan, we had an American service member who needed whole blood, not packed red blood cells, which is what banked ‘blood’ almost always is. I don’t remember why, but he did. We had no whole blood on hand, so I went into the DFAC (eating facility), stood on a table and announced that we needed immediate donations of his type of blood. We immediately had 50+ people willing to donate.
In short, the typical immediate crisis is due to the transfusee’s immune system attacking the donated red cells. This causes two severe problems:
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The transfused red cells dissolve, dumping their contents into the blood stream. The hemoglobin in the red cells is toxic to the kidneys in such free amounts and can shut them down.
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Meanwhile, the immune factors involved in the battle to destroy the “invading” red cells cause the patient’s own blood vessels to leak, leading to low blood pressure, fluid leaving the circulatory system and going places it shouldn’t, like the lungs; and the patient becomes shocky.
To expand a bit on precisely what happens with an acute transfusion reaction, I quote the subscription medical website UpToDate:
Like anything in medicine, there are other ways that transfusions can go very, very wrong. KarlGauss and others have touched on them, too.
Thanks, everybody. Very informative.
That must be what my father was. Being the head of a small general hospital he was often called for when they had a shortage of blood during an operation.
Can anything be done about this as it is happening?
First thing you do is stop the blood transfusion. You remove the tubing, too, and set up new tubing for saline and whatever the doctor orders. You send samples of the patient’s blood and urine and the donor blood to the lab Then you call the doctor and tell her what’s happened and find out what she wants to do - which will be based on what the patients’ symptoms are. Frequent vital signs and close monitoring of the patient’s “ins and out” (how much liquid goes into them by IV and/or mouth, and how much urine comes out) help you figure out what other interventions might help. They may need oxygen, or even to be intubated (put on a breathing machine), need medications to raise their blood pressure, meds to help open their airway if they’re wheezing, meds to lower their temperature, or other supportive measures.
When the lab finally gets back to you, they’ll have information about exactly what kind of reaction is going on (hemolytic - mismatched blood, febrile - sensitivity to white blood cells, platelets or plasma in the blood but not the red blood cells, allergic - allergy to another protein in the blood or sepsis - bacteria got into the donor blood) and how badly the patient’s kidneys have been damaged already.
This is the bit that always worried me. It seemed to me that there was a significant risk of stroke, heart attack, or other quickly fatal outcomes. Yet this is the one I don’t see discussed. Given that the simple tests for blood type depend upon antibody mediated coagulation, it always struck me as a reasonably aggressive reaction, and one that I imagined would be hard to survive. But it seems that it isn’t so, or at least not so bad.
On the contrary, DIC* is as close as we have to a death sentence in this scenario. There’s not a whole lot to discuss about it, honestly, because 50% of your patients who get it will die no matter what you do, and 50% will survive despite anything you do.
We give you fluids. We wait. We watch. Sometimes we give you antithrombins or platelets (things that make your blood clot less or clot more), but that’s pretty rare.
Luckily, most people don’t get DIC from a blood transfusion reaction.
*It’s not nice, but the nickname for DIC in hospitals is “Death Is Coming”. 
OK, that is more what I would expect. However, the above response was the first discussion of the issue, except to name it in passing. With the discussion of management and, at least, some passable expectation of recovery from the other problems, it seemed this one just didn’t rate, which was rather in opposition to my expectations. My gut feeling had been that a wrong group transfusion would kill you outright from DIC, and the other complications were hardly going to rate at all.
That is the bit I find a little puzzling.
My father was a medico, he used to get the annual report from his medical indemnity insurer, which listed many of the cases they had had to either fight, or pay out on in the previous year. I remember reading one of these when I was quite young, and it was a case where a stupid bit of inattention had mixed up blood samples prior to an operation. The patient was given the wrong blood type and died in minutes from DIC. So this set my expectations. I would guess that the rate of transfusion is perhaps an important determinant as to the order things happen in.
The rate, the amount transfused, the procedure, the product, the patient’s condition… Lots of variables.
Lots of safeguards have been put into place since your father’s time, I bet. First of all, we try really hard not to use whole blood anymore - there are just too many different things that can trigger a reaction in whole blood. So if you need platelets, you get a bag of platelets - no red blood cells, no white blood cells, no plasma. If you need volume, you’re probably going to get saline or lactated ringer’s or, much more rarely, plasma - no red blood cells, no white blood cells, no platelets. This change alone reduces the number of transfusion reactions considerably. Think of it like this: if you’re allergic to cats, you need to avoid cats. If we send you into a room filled with dogs and cats, your allergies will act up. If we separate the dogs and the cats and put them into two different rooms, you can go into the dog room without any problem!
Now when you pick up blood products from the lab, a nurse has to go get it, not a tech. The nurse and the lab person have to both independently verify the tag on the blood and its match to the patient. Then when you get the blood to the floor, you have to take it into the patient’s room along with another nurse (RN, not LPN) and both nurses have to check the label and the patient’s wristband *and *ask the patient for their name and birthdate, again independently. These changes also reduce the number of transfusion reactions, especially those of the wrong blood type or the dreaded “Mary Smith got the blood meant for Marty Smith”.
Once you start the blood running (far slower than they used to let it run - you’re right, the rate matters a lot), you’re supposed to stay with the patient for the first 15 minutes to observe any adverse effects. If you think maybe you see a little pallor, or there might be the barest hint of a wheeze, you stop the infusion immediately and get another nurse or your supervisor for a second opinion in minutes. If there’s any doubt, you pull the tubing (so the blood IN the tube doesn’t go into the patient) and flush with saline, and then keep running saline in while you call the doctor. After 15 minutes, if there’s no reaction, you can leave, but you have to check on them every half hour. This increased monitoring and decreased intervention time means that, if a reaction occurs, a minimum of blood has gone in for the body to contend with.
These safeguards, all taken together, have dramatically improved the safety of getting blood products. They haven’t eliminated transfusion reactions, but they’ve made them much, much rarer than they were a decade or two ago.
DIC from a blood transfusion is, generally, a later and rarer reaction than the headache, chills, fever, etc. that we’re looking for. There are nurses who never see a case of it during their careers. DIC is more likely if a lot of blood has gone in, or if someone hasn’t monitored their patient appropriately or (as the quote says) if the patient is in a coma or under anesthetic when they get blood. (It’s a lot harder to assess an unresponsive patient.)