Tissue pO2 and transcutaneous pO2 as guidelines in experimental and clinical drug evaluation

Tissue pO2 measurements on skeletal muscle surface both in patients and in animals in a model of occlusive disease revealed local tissue hypoxia that, until now, had not been detected with any other method. This kind of local tissue hypoxia is interpreted as a disturbance of local microflow distribution in the presence of unchanged regional blood flow rate. In response to buflomedil infusion, tissue pO2 histograms improved without any change in regional blood flow or distal blood pressure. In comparison to healthy volunteers, transcutaneous pO2 measurements in patients allowed establishment of of tcpO2 profiles along the lower extremity which were in agreement with angiographic localization of vessel occlusion. In a preliminary study, buflomedil infusion (3 mg/kg) over 30 minutes caused a significant increase in tcpO2 in 5 patients in the absence of any significant change of segmental blood pressure. It is concluded that both tissue pO2 and tcpO2 measurements are able to provide unique information about local changes of the microcirculation in occlusive vessel disease.