“…Data from humans are sparse. In a randomized trial of patients undergoing elective knee surgery under regional anesthesia, the oxygen and lactate contents in the femoral vein decreased significantly after local ischemic preconditioning using a tourniquet (Van et al, 2008). These authors did not measure flow to calculate VO 2 , but several studies have demonstrated, during ischemic arterial occlusion in the coronary, femoral or brachial arteries, that flow is increased during the period of reactive hyperemia, but returns to baseline values in 3 to 10 minutes (Ellins and Halcox, 2011;Engelke et al, 1996;Hayman et al, 2010;Krishnan et al, 2011;Olivecrona et al, 2004;Olivecrona et al, 2007).…”