Transcutaneous PCO2 level as an index of tissue resistance to ischemia

The authors performed a retrospective study on a data base of 525 patients with peripheral arterial disease, to analyze the pathophysiologic meaning of resting transcutaneous pressure of carbon dioxide (PCO2) and of CO2 production during three minutes of local ischemia. The resting and postischemic PCO2 and its maximum increase related to rest (PCO2 production) were measured with Kontron 7640 equipment. The results show a significant increase of PCO2 production in the Fontaine stage 2A (183 patients, 4.61 mmHg, P < 0.0001), in stage 2B (194 patients, 5.22 mmHg, P < 0.0001), in the third stage (83 patients, 6.10 mmHg, P < 0.0001), and in the fourth stage (53 patients, 8.66 mmHg, P < 0.0001). Only the patients at the first stage showed an insignificant increase, perhaps because of the small number (12) in this group. The authors feel that the measurement of tcPCO2 production during local ischemic stress can be a very important parameter for evaluating peripheral arterial disease as an expression of metabolic tissue performance and, overall, of the tissue resistance to ischemia.