Clinical and Hemodynamic Effects of Stepwise Lowering of Hemoglobin Concentration in Patients with Intermittent Claudication

Abstract

This study evaluates the effect of stepwise lowering of the hemoglobin (Hb) concentration on maximal walking distance (MWD) and hemodynamics in pa tients with intermittent claudication. The results in a study group (n = 6) were compared with those of a control group (n = 6) whose members were not sub jected to venesections. An average decrease of Hb concentration from 151 ± 4 to 121 ± 3 g/L did not significantly influence MWD, the result being 282 ± 62 meters before venesections and 255 ± 54 meters after three to five (mean four) repeated venesections. Transcutaneous oxygen pressure was measured at the dorsum of the foot before and after exercise and did not change with a gradual decrease of the Hb concentration. Maximal heart rate, painfree walking distance, ankle pressure, and blood lactate concentration were also unchanged. An average venesection volume of about 1.4 liters whole blood within fourteen days, without isovolemic replacement, did not change the blood volume, which was 5.1 ± 0.4 liters be fore and 5.0 ± 0.5 liters after venesections. In conclusion, hemodilution accomplished by venesections did not have a clinically or physiologically beneficial effect in patients with severe intermittent claudication. However, hemodynamics and clinical symptoms were not affected by a considerable decrease in the arterial oxygen content within the normal Hb concentration range.