Optimal hematocrit in patients with intermittent claudication. Exercise-induced muscle tissue oxygen pressure after stepwise hemodilution.

In patients with severe intermittent claudication and concomitant high hematocrit values a hypervolemic (stepwise infusion of 500 ml 10% hydroxyethylsolution: mean molecular weight 200.000/substitution degree 0.5) or isovolemic hemodilution (stepwise venesection and subsequent infusion of 10% hydroxyethylstarch solution 200/0.5) was performed intraindividually. Measurements of muscle tissue oxygen pressure (pO2) values using a standardized pedalergometric exercise test were performed. The optimal results of muscle tissue pO2 behaviour after pedalergometric exercise were found at average hematocrit values of 40%-41% when isovolemic hemodilution was applied. Hypervolemic hemodilution improves muscle tissue oxygen supply at rest, but shows a retarded reactive hyperoxia under exercise conditions. Thus it is likely that in patients with severe intermittent claudication an optimal tissue oxygen supply can be obtained in the case of isovolemic hemodilution at hematocrit values of about 40-41%.