THE SHIFT TO THE LEFT

For many years it appeared that physiologists, and physiologists alone, puzzled over the causes and significance of alterations in the position of the oxygen-hemoglobin equilibrium curve. The reports by Benesch and Benesch1 and Chanutin and Curnish2 in 1967, concerning the role of red cell organic phosphates in determining the affinity of hemoglobin for oxygen, have served to rekindle curiosity in this problem of oxygen transport and produced a common focus of clinical interest for neonatologists, hematologists, biochemists, and the now nearly forgotten physiologists. The oxygen-hemoglobin equilibrium curve of normal adult blood is depicted as the center curve in Figure 1.