Effect of Altitude on Erythropoiesis and Oxygen Affinity in Anaemic Patients on Maintenance Dialysis

Abstract

Abstract. Six anaemic patients with terminal renal failure on maintenance haemodialysis and three healthy control subjects were exposed to altitude hypoxia at Jungfraujoch (3450 m above sea‐level). In normal subjects plasma erythropoietin (ESF) as determined by the exhypoxie mouse assay exhibited the expected rise after 24 h (from 0.25 to 3.09% 6 *Fe incorporation). In the patients a smaller but still significant rise was demonstrable (from 0.39 to 2.18% M Fe incorporation), indicating that even severely damaged kidneys with negligible exocrine function retain a definite endocrine reserve for ESF production. For this reason bilateral nephrectomy should be avoided in these patients if possible. 2,3‐DPG and P 50 (as corrected to pH 7.4) as well as blood pH increased within 24 h after altitude exposure in the control subjects, as described previously. In the patients the two parameters were already elevated under baseline conditions. Upon hypoxic stimulation they rose further (from 44.7 to 56.5 (junoles/10 11 Ec. and from 28.6 to 30.1 mmHg respectively), while a definite fall in whole blood pH occurred. High altitude exposure was tolerated remarkably well by the dialyzed patients in spite of the presence of anaemia and severe renal failure.