Q: I am writing a time travel where one of the characters is a modern doctor who is sent back in time (15th century) with his family. I want to have him do something medical to save the life of the heroine (I was thinking heroine needs blood transfusion which would require a blood typing system) Any idea how it could be accomplished? I was also thinking that the heroine has rare blood type. Would that be Type B?
Doreen Jensen, Ontario, Canada
A: This is an interesting scenario in that you have someone with modern knowledge transported back to medieval times. This means he would have all the medical knowledge of transfusions––which of course did not exist then––but no scientific equipment to help. Not to mention that merely bringing it up might get him killed by the church––but that’s another issue.
The first human transfusion took place in France in 1667 when Jean-Baptiste Denis successfully transfused sheep blood into a fifteen year old boy. The first human to human transfusion was in 1818 and was performed by James Blundell on a patient suffering from postpartum bleeding. Even he had no way of matching the blood and, in fact, didn’t understand that there were blood proteins that made transfusions incompatible between many people and successful between others. It wasn’t until 1901 that Karl Landsteiner discovered the ABO blood groups and begin to understand the nature of transfusions and transfusion reactions. In 1939, the Rh factor was discovered, also by Landsteiner along with several other physicians, thus refining the process further.
So your time-traveling doctor would know all of this and would also know that transfusions are only successful if the donor and recipient match one another as far as blood type is concerned. But he would have no way of testing the donor and recipient for blood type and compatibility, which of course is essential to avoid harming or killing the recipient. But, there is a way around this. He would know that two compatible bloods could be mixed and no reaction would occur while if they were not compatible clumps would form. We call this agglutination and it is the basis of a transfusion reaction. He could simply mix the blood of the donor with that of the recipient––which is more or less the way it’s done today––and look for this reaction. The problem? This agglutination can only be seen microscopically and there were no microscopes in the 15th century.
The microscope was discovered in 1590 by two Dutch spectacle makers–Zacharias Janssen and his son Hans. They employed the glass lenses they used in their spectacle making, which had been around since the 13th century. When they placed these lenses in tubes, they discovered that they magnified any image viewed through the tube. This was the precursor of the true microscope which was developed nearly 70 years later (1660s) by Anton van Leeuwenhoek. So, your modern physician would know this and could perhaps fashion his own crude microscope from spectacle lenses. This would allow him to see any agglutination that might occur. He could then simply take the recipient’s blood and test it against several potential donors and see which one had the least reaction. This would be crude cross matching but it could work. He would then know whose blood to use in the transfusion process.