CHANGES OF DERMAL HEMOGLOBIN OXYGENATION AND CONCENTRATION IN HEALTHY-SUBJECTS AND IN PATIENTS WITH PERIPHERAL ARTERIAL OCCLUSIVE DISEASE DURING AND AFTER ACUTE-ISCHEMIA

Background: Oxygen saturation (S-HB) and concentration (C-HB) of derma l haemoglobin play an important role in the nutrition ofthe skin. In p atients with severe peripheral arterial occlusive disease (PAOD) they are reduced at the forefoot. We investigated the changes of the named parameters during an acute ischemia and during reactive hyperemia usin g an occlusion test. Patients and Methods: Dermal reflection spectra w ere conducted from the forefoot of 11 healthy subjects and 39 patients with peripheral arterial occlusive disease of various stages at rest, during, and after an arterial occlusion at the thigh. Using a multico mponent analysis S-HB and C-HB were calculated iteratively. The halfti me of the post-occlusive increase of S-HB (post-occlusive recovery hal ftime PORHT) and the relation of post-to pre-occlusive C-HB (post-occl usive reactive hyperemia PORH) were calculated to estimate the dynamic of the post-occlusive inflow of blood. TcPO2 (37 degrees C) was addit ionally determined at the forefoot. Results: In patients from stage II I and IV all resting values were lower compared to controls. TcPO2 dec reased in all persons to 0 mm Hg during the occlusion, S-HB was betwee n 0 and 10%, while C-HB remained unchanged. In healthy subjects and in patients with claudication the post-occlusive values exceeded the pre occlusive ones, while in some patients with higher stages of the disea se this could not be found. There was a marked on the stage of the dis ease depending difference in the post-occlusive course between control s and patients: in healthy subjects it rook only 5.5 +/- 4.8 s until S -HB reached half of the maximum value, in patients from the stage IIa group 26.8 +/- 16.9 s (p < 0.001) was measured while in stage III and IV the value was 132 +/- 75 s (p < 0.001). Conclusions: During ischemi a a decrease of the haemoglobin oxygen saturation (S-HB) and tcPO(2) w as found Haemoglobin concentration (C-HB) remained constant, hence a s ignificant shift of blood from skin to muscle did not take place. PORH T was selectively dependent on the stage of the disease. The occlusion manoeuvre enhances the significance of reflection photometry in PAOD.