SIMULTANEOUS LASER-DOPPLER AND TRANSCUTANEOUS OXYGEN-TENSION MEASUREMENTS IN CLAUDICANT PATIENTS

Laser Doppler (LD) flux and transcutaneous oxygen tension (TcPO2) were measured in supine and sitting position at the dorsum of the foot wit h local skin temperature of 37 degrees C and 44 degrees C in 50 patien ts with stage IIb of chronic peripheral arterial occlusive disease (CP AOD) and in 30 healthy controls. The statistical analysis showed no si gnificant differences between patients and controls in the supine and sitting position at 37 degrees C. A lower increase of LD- flux and TcP O2 could be noticed during hyperthermia and reactive hyperaemia in the patients group as well as a significant prolongation of oxygen (ORT) and flux reappearance time, of postocclusion time to peak flux and oxy gen peak, of postocclusion time to half of peak flux and oxygen peak a nd of time to flux restoration at preocclusion levels (FTMAX) during r eactive hyperaemia test. FTMAX and ORT allowed a clear separation betw een patients and controls and exhibited a high reproducibility. A regr ession analysis equation was derived with the most significant paramet ers indicating the presence and the severity of the disease. Moreover, the estimated time parameters of LD - flux and TcPO2 were correlated with the US - Doppler ankle systolic blood pressure indices and theref ore with the impairment of the macrocirculation. In summary, we find t hat skin perfusion in patients with intermittent claudication is not d ifferent from normal subjects under basal conditions. However, maximal perfusion is reduced and the time to peak perfusion after a provocati ve stimulus is delayed. These findings confirm the importance of the u se of provocative tests (i.e., local hyperthemia or reactive hyperemia ) when using transcutaneous oximetry or Laser Doppler flowmetry to eva luate peripheral arterial occlusive disease. Moreover, our studies ind icate that dynamic measurements (i.e., time to peak flow) may be more discriminating than absolute values of peak flow.