[Attenuation of post-ischaemic reactive hyperemia during lifting of the lower limbs]

With a view to determining to what extent changes in the position of the lower limbs influence post-ischaemic reactive hyperaemia, an ischaemic test was run on a group of normal subjects and patients with peripheral obliterative arteriopathy. Reactive hyperaemia was induced both in the usual supine position and then with the leg raised at 60 degrees to the horizontal. Raising of the leg significantly reduced the amplitude and duration of hyperaemia in both groups, though the differences between them with regard to the hyperaemic flow pattern were not affected. Various explanations of the results are offered. Raising of the limb appears to act more on local mechanisms controlling the peripheral arterial flow than on factors responsible for the genesis of RH. In particular, over and above the reduction of hydrostatic pressure, importance may be ascribed to the disequilibrium created by raising the limb on the component of vasal transparietal pressure. In arteriopaths, these factors are made more potent by obstruction of the main limb artery and arteriosclerotic impairment of the colateral circulation. Lastly, emphasis is placed on the possibility that the apparent metabolic deficiency created by ischaemia and remedied by RH is at least partly greater than the real deficiency and the tissues actual metabolic requirements.