Blood transfusion

Blood transfusion is the process of transferring blood from one person's body to another. A severely injured person or one undergoing surgery may need extra blood to replace that which has been lost. If the extra blood is not available, the person can go into shock and die.

Folk medicine and ancient practice long considered blood to have beneficial, healing properties. Perhaps the earliest recorded case of blood transfusion was that of Pope Innocent VIII (1432-1492). The Pope was transfused in April 1492 with the blood of three young boys. The outcome indicates why transfusion attempts were rare and dangerous: all three boys died.

After William Harvey (1578-1657) explained the mechanism of blood circulation in 1628, interest in transfusion grew. An Italian physician, Giovanni Colle, gave the first concise description of a blood transfusion in 1628. An English clergyman, Francis Potter, seems to have experimented with transfusions in the 1650s. In the 1660s, the Royal Society of London (England) sponsored a series of transfusion trials. This was after Sir Christopher Wren (1632-1723), the famous architect, used a quill-and-bladder syringe to inject fluid into the vein of a dog. The injection was done to demonstrate a new method of administering medications. Richard Lower (1631-1691) continued the experiments at Oxford University in England and performed the first direct blood transfusion from one dog to another in 1665 by connecting an artery to a vein via a silver tube.

French physician, Jean Baptiste Denis (1643-1704), used Lower's technique in June of 1667 to perform a transfusion from a lamb to an ill human. Several months later, both Denis and Lower transfused blood from a sheep to a man. The promising new technique was abruptly halted in 1668 when one of Denis's transfused patients died. Even though the cause of death was poisoning by the patient's wife, transfusions were banned in France and did not become medically established in England.

In 1818 James Blundell, a physician at Guy's Hospital in London, revived the practice of transfusion by using a syringe to inject blood from human donors. At first Blundell transfused only hopeless cases, but in 1829 he used blood transfusion successfully to treat a woman with postpartum hemorrhage. Both Blundell and James N. Aveling improved the apparatus for carrying out transfusions. The technique was widely used during the Franco-Prussian War (1870-1871).

Typing Blood

Blood transfusion remained a risky procedure. The donor's blood tended to coagulate, and recipients were likely to suffer a fatal transfusion reaction. The discovery of blood groups in 1900 solved the problem of fatal reactions. In 1914 the use of sodium citrate as an anticoagulant answered the problem of blood clotting. Austrian-American pathologist Karl Landsteiner (1868-1943) showed the existence of three distinct blood types (groups; the number rose to four in 1902) in an "ABO" system. Antigens in some types reacted adversely to antibodies in other types, causing the clumping of red cells. The clumping could fatally block blood vessels. Landsteiner's findings made it possible to identify donor and recipient blood types and thus avoid the deadly transfusion reaction in most cases. Typing of blood for transfusion began in

Perhaps most serious of the remaining risks of blood transfusion is the possibility of transmitting disease via the donor's blood. Of special concern is the transmittal of the HIV virus and hepatitis.

The Modern Procedure

At first, blood transfusion was done via direct connection between donor and recipient. George Washington Crile (1864-1943), an American surgeon, developed a standard surgical method of blood transfusion. After surgically exposing a recipient's vein and a donor's artery, a physician clamped shut the vessels and attached a small tube as a conduit between them. When the surgical clamps clamps were opened, blood flowed from donor to recipient. Edward Lindeman took the procedure out of the operating room in 1913 with a simple needle puncture technique. This method also allowed exact measurement of the amounts of blood being transfused. With all these advances in place, blood transfusion spread rapidly and became firmly established during World War I (1914-1918).

Blood Banks

Once blood transfusion was in wide use, storage of donated blood became a problem. The first "blood bank" was set up by Dr. Bernard Fantus in 1937 at Cook County Hospital in Chicago, Illinois. A method of preserving red blood cells for up to 21 days with acid citrate dextrose was developed in the 1940s. African-American surgeon Charles Richard Drew studied in depth a way to preserve and store blood ready for instant use. He discovered that plasma could be processed and reserved for a long time, and transfused without regard to blood type or matching in place of whole blood. Drew established blood banks in England and the United States during World War II (1939-1945). These banks saved thousands of lives by making blood transfusion available to the wounded.

Today, blood transfusion remains a widely used and critical medical procedure. After World War II, methods were developed for separating the various constituents of blood. As a result, in addition to whole blood, a patient may receive "packed" red cells, granulocytes (white cells), platelets, plasma, or plasma components. Both natural and artificial blood substitutes are also used. Perhaps most serious of the remaining risks of blood transfusion is the possibility of transmitting disease via the donor's blood. Of special concern is the transmittal of the HIV virus and hepatitis. For this reason, donated blood is carefully screened.