Blood Transfusion: Receiving Blood
Guest: Dr. Jerry Squires – Pathology and Laboratory Science, MUSC
Host: Dr. Linda Austin – Psychiatrist, MUSC
Dr. Linda Austin: I’m Dr. Linda Austin. I’m interviewing Dr. Jerry Squires, who is Associate Professor of Pathology and the director of our transfusion service here at the Medical University of South Carolina. Dr. Squires, in a previous podcast, we talked about donating blood. Let’s talk about the other end of it; receiving blood. I’m sure question on most on people’s mind is; especially in this post-HIV environment; actually, HIV is an ongoing issue, how safe is it to receive blood?
Dr. Jerry Squires: You know, the praise we often hear from blood centers is that blood is safer than it has ever been. In some ways, that sounds somewhat trite. But, if one looks at the statistics related to infectious diseases caused by blood transfusion, it really is safer than it has ever been.
I’ll give you a couple of examples. Certainly, the disease that alerted all of us to the potential infectious risks of blood was HIV. Right now, the risk of contracting immunodeficiency virus through a blood transfusion is about one in two million. The risk of getting hepatitis C from a blood transfusion is also about one in two million. So, the risks of the diseases that we all fear the most, with regard to blood transfusion, are, really, remarkably rare.
Dr. Linda Austin: Now, you mention diseases that we fear the most. How about other diseases that we’re not even so aware of? Are there risks?
Dr. Jerry Squires: There are risks with blood transfusion, just as there are risks with all medical therapies. There’s a risk for hepatitis B. The risk there is about 1 in 200,000. There’s a risk for HTLV-1, and -2. Again, the risk there is about one in four million. There’s a very remote risk for syphilis. There’s a very remote risk for West Nile Virus. There’s a very remote risk of even diseases such as Chagas Disease.
Dr. Linda Austin: But those are teeny tiny risks.
Dr. Jerry Squires: It’s extremely rare to contract any illness as a result of blood transfusion.
Dr. Linda Austin: Now, let’s talk about who ends up getting blood transfusions. This may be a hard question to answer, but how often is it anticipated, or predicted, and how often is it just something that comes up out of the blue; either an operation that doesn’t go the way the surgeon thinks, or, let’s say, an accident, or that sort of thing?
Dr. Jerry Squires: Well, for many surgical procedures, we can, with a good deal of accuracy, predict how much blood is going to actually be used. So, if you’re going to need a certain type of surgery, your surgeon, with about 90 percent accuracy is going to be able to tell you just how many units of blood you’re actually going to need for that surgical procedure. What is more difficult though are the unexpected needs for blood; the motor vehicle accident, the trauma that results from gunshots, or other unexpected events. Those, in many instances, require really significant amounts of blood.
Dr. Linda Austin: How much blood does a human being have to lose before the physician says they need a blood transfusion?
Dr. Jerry Squires: About three to four units of blood is when a person begins to be symptomatic.
Dr. Linda Austin: A unit is a pint?
Dr. Jerry Squires: It’s about a pint. So, if you lose three to four pints of blood, you will begin to exhibit those symptoms that are suggestive of your need for blood. And it’s about that time that the physician will begin considering transfusing you.
Dr. Linda Austin: And we’ve all heard, maybe from watching ER, of the term type and cross-match.
Dr. Jerry Squires: Sure.
Dr. Linda Austin: What is that? That must be what you become engaged in, supervising, a good bit.
Dr. Jerry Squires: Mmhmm. Well, we, as humans, have eight different blood types. We have A+, A-, O+, O-, B, AB+, and AB-. So, you add all that up, it’s about eight different types. In order for a blood transfusion to be safe, you must get blood of your type, or you must get what’s called universal donor blood. In other words, I’m a group A+. I should receive A+ blood. I could, in an emergency, if there’s no time to determine what my blood type is, get O+, or O-. That’s the universal donor.
So, a typing is just to determine what your blood type is so that we can, then, provide you blood of the same type. A cross-match, on the other hand, is just that final check. It’s a double-check on the type that you are, and the type of the selected unit. We mix those two together to make sure that there’s no abnormal reaction. That’s called the cross-match, or compatibility test. That is, sort of, the double-check; the final check, that everything is fine for your transfusion.
Dr. Linda Austin: How often, on a national level, is there human error in that process, so that a mistake is made?
Dr. Jerry Squires: That is very difficult to determine. And part of that is that we, in the United States, don’t have a national registry, where all of this data, from all of the hospitals, and blood centers, is nationally accumulated. However, depending on the type of hemolytic reaction, which is, generally, the wrong person getting the wrong unit of blood occurs in about 1 in 100,000 instances.
Dr. Linda Austin: And I’m sure institutions track their own; their own statistics on that.
Dr. Jerry Squires: Oh yes, we do. And we haven’t had, knock on wood, any of those in a long time.
Dr. Linda Austin: Here at MUSC?
Dr. Jerry Squires: Exactly.
Dr. Linda Austin: Good. After a person has received a transfusion, I’m sure, oftentimes, they want to give back. How long do they have to wait in order to do that?
Dr. Jerry Squires: Once you get a unit of blood, we ask people to wait at least a year before they donate themselves. The reason for that is, number one, we want to make sure you’re well. And, number two, we want to make sure, with that unit of blood we’ve given you, even as safe as it is, there wasn’t that incredibly remote chance that a disease was transmitted; and then when you donate, transmitted, yet, to another person. So, we put in, with an abundance of caution, that one-year deferral.
Dr. Linda Austin: How about international donations? Are there situations when that happens, when there is, let’s say, a great catastrophe in some foreign country?
Dr. Jerry Squires: That can happen. It’s remarkably difficult to ship blood from one country to another, unless it is for a bona fide very rare, or unusual, unit, or a very rare, unusual blood type. That can be done on a unit-per-unit basis. But it’s very difficult to ship blood in bulk; many units, from one country to another. One country, versus another country, will have slightly different criteria for their donors, and for transfusion.
Dr. Linda Austin: So, as director of our transfusion program here, what are your biggest headaches, concerns? What are the things that you worry about most that you’re responsible for?
Dr. Jerry Squires: One of the most important things that I worry about is making sure that we sufficient blood to treat all of the patients that we have. Generally, our inventory is very dependent upon what our supplier can provide. That, in turn, is dependent upon altruism; the will, the desire, of individuals in our community.
Having enough blood is certainly one of the biggest concerns that I have. The second concern is that, because we’re a referral center, many of our patients come in with somewhat unusual problems and, therefore, somewhat unusual blood needs. So, being able to meet those specific needs is a concern as well.
Dr. Linda Austin: Dr. Squires, thank you so much for talking with us.
Dr. Jerry Squires: Glad to do it, and thank you.
If you have any questions about the services or programs offered at the Medical University of South Carolina, or if you’d like to schedule an appointment with one of our physicians, please call MUSC Health Connection at: (843) 792-1414.