Depressant effects of high concentrations of inspired oxygen on erythrocytogenesis. Observations on patients with sickle cell anemia with a description of the observed toxic manifestations of oxygen

This report describes the effect of the continu-ous inhalation of 70 to 100 per cent oxygen for 8 to 20 days on the cellular elements of the blood of patients with sickle cell anemia. The investi-gation was originally begun in an effort to reduce the degree of intravascular sickling of red blood cells. There were two reasons for trying to pro-duce this result: (1) Diggs (1) and Bauer (2) have suggested that the pain of sickle cell crises may result from anoxia of tissues caused by oc-clusion of blood vessels with elongated clumped cells, and (2) the increased rate of hemolysis in sickle cell anemia might possibly be due to the greater trauma to which sickled cells are sub-jected during circulation. Therefore, if the ab-normal shape could be corrected, the pain of crises might be relieved, the rate of hemolysis decreased, and the degree of anemia lessened. It is well known that in vitro the erythrocytes of patients with sickle cell anemia will become bi-concave discs when they are exposed to air or oxygen, and become sickled when they are ex-posed to carbon dioxide (3, 4). Sherman (4), furthermore, demonstrated that there are fewer sickled cells in arterial than in venous blood. But, when this study was begun, no one had shown that the oxygen tension of arterial blood could be increased sufficiently to influence the degree of intravascular sickling. That this re-sult might be accomplished, however, seemed likely since (1) Boothby, Lovelace, and Uihlein (5) were able to increase alveolar oxygen tension to more than 500 mm. Hg, and (2) Behnke (6