The key reason for varied outcomes in blood transfusions during the 1800s was whether patients received compatible blood types. Without knowledge of blood compatibility, many patients suffered serious complications or died after transfusions. Those who received the right match had better chances of recovery.
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In the 1800s, the key reason for the varying outcomes of blood transfusions was due to whether patients received compatible blood types. The practice was still new, and the absence of knowledge about blood types led to many unsuccessful and even fatal exchanges. The crucial role of blood compatibility highlights why some individuals survived while others did not. ;