A Study of the Sickling Phenomenon and Oxygen Dissociation Curve in Patients with Hemoglobins SS, SD, SF and SC

Abstract 1. Data on pO2, T50, n values and per cent of sickle cells were obtained in patients with hemoglobins SS, SD, SF (S-thalassemia) and SC. In general the per cent of sickle cells was proportional to the per cent of hemoglobin S. The number of sickle cells was, however, influenced by the other type of hemoglobin present and by the pO2. Values for T50 were greater than normal, and values for n were less than normal. 2. The effect of therapy with O2, CO2, NaHCO3 and MgSO4 on the per cent of sickle cells in arterial and venous blood was determined. Only inhalation of O2 reduced the per cent of sickle cells. 3. The rate of sickle cell formation and its reversal were determined under conditions of deoxygenation and oxygenation. These were found to be a function of the type of hemoglobin combinations present. 4. The oxygen dissociation curves were found to be shifted to the right of the normal curve indicating a decreased affinity for oxygen. In two patients the Bohr effect was determined and found to be normal.