Effect of Hemodialysis on Oxygen-Hemoglobin Affinity in Chronic Uremics

¹ Recipient of grants-in-aid from Eli Lilly Company and Indiana Kidney Foundation
² Departments of Medicine, Indiana University and Veterans Administration Hospital, Pulmonary Research Laboratories, Indianapolis

P₅₀, plasma pH, red cell pH, 2,3-DPG, ATP, lactate, pyruvate, and glycolytic rate were measured before and after hemodialysis in 25 patients on chronic hemodialysis, The prehemodialysis—resting 2,3-DPG level and P₅₀ were elevated in accordance with the degree of anemia. The resting lactate and glycolytic rate were mildly elevated. Plasma and red cell pH increased significantly with dialysis. The in vivo P₅₀ decreased significantly, whereas the in vitro P₅₀, 2,3-DPG, and ATP levels remained constant. The fall in the in vivo P₅₀ can be attributed entirely to the rise in red cell pH or Bohr effect. The decrease in the in vivo P₅₀ during hemodialysis may transiently impair oxygen oxygen delivery in these Patients. Marked shifts in pH, especially into the alkalemic range, should be minimized, particularly in patients undergoing frequent or prolonged hemodialysis.