Alfred Blalock

The Blalock-Taussig shunt is a surgical procedure developed by Alfred Blalock and cardiac surgeon Helen Taussig (with vital lab work by Vivien Thomas) at Johns Hopkins in 1944 to treat Tetralogy of Fallot, a congenital cyanotic heart defect commonly called 'blue baby syndrome.' The operation connects the subclavian artery to the pulmonary artery, increasing blood flow to the lungs and improving oxygenation.

While at Vanderbilt University in the 1930s, Blalock demonstrated that traumatic shock was primarily caused by the loss of blood and other fluids from the circulatory system, not by a hypothetical circulating 'toxin.' His finding that whole blood or saline replacement was the critical intervention overturned earlier theories and became the standard treatment for shock, especially relevant during World War II battlefield medicine.

Vivien Thomas was an African American surgical technician and lab supervisor who worked alongside Blalock for decades at Vanderbilt and then Johns Hopkins. Thomas designed and perfected the surgical technique for the Blalock-Taussig shunt in animal experiments, standing behind Blalock during the first human operation in 1944 to guide him through the procedure.

Blalock spent the first part of his career at Vanderbilt University in Nashville, Tennessee, where he conducted his landmark research on shock, before moving to Johns Hopkins University in Baltimore in 1941 as chairman of surgery. At Johns Hopkins he remained for the rest of his career, establishing it as a major center for cardiac surgery through the blue baby operations.