Unlike all other medicines, blood transfusion was put into use without ever having had a definitive, double-blind test. Is it safe? Was it ever safe?
Likely you've heard blood being referred to as "type A," "type B, or "type O." These distinctions refer to antigens, markers on the surface of red blood cells. So far researchers have discovered 29 different "types." The antigens essentially make each person's blood unique; they do not play well with others. Mismatched blood was the reason for the death of nearly all early transfusion patients. Even with all the technology available today, it is estimated that about one in 12,000 units of transfused blood in the United States is not matched correctly to the recipient.
Your body creates red blood cells at the astonishing rate of 2 million to 3 million per second! It does so because 2 to 3 million blood cells are dying per second. You have 10 units of blood, all together. That means in any given stored unit of blood, 200,000 to 300,000 red blood cells are dying each second. If a unit of blood is stored for just one hour, it now contains 72,000,000 dead cells. In a day, that's over 18 billion dead cells! I'm not feeling real great about 18 billion dead anything being put into my body.
What's the number of dead cells after a week? How long before they begin to putrify?
Other blood constituents, such as white blood cells, platelets, antibodies and hormones also begin to break down and die in stored blood.
In the normal course of things, these broken down and decaying blood constituents are filtered out by your liver and kidneys. They pass out of your body in your feces and urine.
When a unit of blood is drawn from someone, some of this waste material in their blood was on it's way to the donor's kidneys and liver and got sidetracked into the IV needle, to be stored for transfusion. I'm sure this isn't a picture you want in your mind, but like it or not, accepting a blood transfusion means you are taking into your body a stranger's waste products.
But there's more.
The blood rushing around in your bloodstream, particularly as it goes by your nasal passages, collects nitrogen atoms and oxygen atoms and generates a chemical called nitric oxide. Nitric oxide is vital to your blood's ability to distribute oxygen. Nitric oxide signals your capillaries to dilate to allow the comparatively large red blood cells to squeeze in. Without that snug fit, they can't offload oxygen. And getting oxygen to your cells is kind of the whole point of transfusing blood.
However, nitric oxide is a gas. When blood is removed from a donor and stored, it immediately begins off-gassing its nitric oxide, just as the fizz leaves an open bottle of Pepsi. Some tests indicate that stored blood has lost most of it's nitric oxide - hence most of its oxygen-delivering capacity - within three hours of being removed from a donor.
For these and other reasons, many doctors are taking a long, hard look at blood transfusions. Several studies have shown that patients that are treated without blood transfusions have shorter stays in the hospital, and fewer post-operative problems.
For example, doctors such as Dr. Jimmy Chow of St. Luke's Medical Center in Phoenix, as well as others, have developed micro-invasive hip replacement procedures. Hip replacement used to be a bloody operation, but nowadays hip-replacement patients lose almost no blood.
Next time you read a story that uses the expression "life saving blood transfusion," you might want to forward this article to the writer of that story.
Your comments are welcome. To read my other columns about blood medicine, click here.
Bill K. Underwood is a columnist and author of several books. You can help support this site by following the link here to Amazon.com to purchase a book.
Fascinating! Well-written!
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