Monday, March 19, 2007

Evolution of blood transfusion

This morning's Dept. of Surgery Grand Rounds featured an historical talk by resident Dr. Laszlo Kiraly on the "Evolution of Blood Transfusion." Studies of the efficacy of transfusions and papers on best practices abound in the contemporary literature, and Dr. Kiraly's talk reflected this pace of development: nearly two thirds of his presentation discussed the history of the field since the 1980s.

Kiraly started at the beginning, though, mentioning the literal blood baths once taken by the ancients as remedies for a host of maladies. He traced the first transfusion to 1492, when Pope Innocent VIII reportedly received blood from three young boys before he (and they) died. (Kiraly admits that this may be a legend dating from a slightly later time period, but notes that the story shows that at least the idea of blood transfusion existed early on.)

Zipping through the intervening centuries, Kiraly brought the audience to the brink of World War I, emphasizing that wars and medical breakthroughs often go hand-in-hand. By 1918, preserved blood was being used successfully on the battlefields of Europe, but it was really the Spanish Civil War (according to Kiraly) that saw widespread use of transfusions for casualties, primarily because civilians began to be tapped as donors for blood banks. In WWII, America developed the "Blood for Britain" program, and started checking blood for bacterial contamination. Germans, meanwhile, began paying civilian donors while the Russians used cadaveric blood with some success.

The next advance came with the development of plastics for storage (see, they're not all bad!) and by 1979, shelf life had increased to 42 days. The 1960s and 1970s were the golden days of transfusion, and there was little thought devoted to disease transmissibility. That all changed, of course, with the appearance of HIV/AIDS on the world scene; in 1983 the FDA mandated the first donor screenings.

These days, the public perception of blood transfusion is that it is a very high-risk procedure. Kiraly notes that while perceived risk from viral infection is actually quite low, there is some moderate risk from misidentification (being addressed now with plans to individually barcode all blood containers), and risk as well from bacterial contamination. He focused on complications from transfusion-related acute lung injury (TRALI) and transfusion-related immunomodulation (TRIM)--the latter actually being of possible benefit in patients in whom a depressed immune system may be favorable to a positive outcome (such as transplant recipients).

After touching on a few of the blood substitutes used over the years, from milk to PolyHeme, Kiraly ended by describing the current state of transfusion science as perched on a balance point between skepticism and enthusiasm. As research progresses, the history of blood transfusion will only get more interesting...

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