The Oxygen Affinity of Haemoglobin in Chronic Renal Failure

Abstract

S ummary . The position of the oxygen dissociation curve of haemoglobin was established in 42 healthy subjects and 30 anaemic patients with chronic renal failure, 20 of whom were being treated by maintenance haemodialysis. Twenty‐four patients showed right‐shifted dissociation curves with a different distribution pattern from that in normal subjects. This study has shown a negative correlation between the degree of anaemia and the half saturation value of the dissociation curve (r = ‐ 0.59) in chronic renal failure. In patients with undialysed chronic renal failure the patient's own hydrogen ion concentration was found to be important in determining the position of the curve. The mean advantage in the calculated haemoglobin concentration due to the right shift in the curve was 0.5 g/100 ml more than that measured photometrically. These changes could result in as much as 25% saving in cardiac output in a resting subject. We therefore consider that these compensatory changes are helpful in ameliorating tissue hypoxia in anaemic subjects.