A NEW METHOD FOR THE ASSESSMENT OF TISSUE HEMOGLOBIN OXYGENATION IN PATIENTS WITH CHRONIC VENOUS INSUFFICIENCY

Venous incompetence often leads to ulceration of the skin of the lower limb due to a disturbance of skin microcirculation. We investigated 1 0 healthy subjects and 18 patients with chronic venous insufficiency b y means of a fast scanning reflection photometer and determined noninv asively the hemoglobin oxygen saturation (S-HB) and the relative conce ntration of hemoglobin (C-HB) in the skin of the forefoot and at the c alf, 10 cm proximal of the inner malleolus during positional changes. In supine position no significant differences were found. During sitti ng and standing S-HB dropped and was significantly lower in patients a t both locations (calf, standing, patients 22.2 +/- 10.6% vs controls 48.2 +/- 13.5%, P < 0.001). C-HB increased in patients during standing from 0.71 to 2.13 +/- 0.33 aU (in controls from 0.69 to 1.49 +/- 0.28 aU, P < 0.001). Activation of the muscle pump decreased C-HB and incr eased S-HB in patients and in controls. After the movements were stopp ed, S-HB decreased again and fell to the initial low values eight time s faster in patients (7.4 +/- 5.3 vs 57.5 +/- 19.6 sec, P < 0.001). C- HB increased four times faster in patients (7.2 +/- 6.1 vs 29.9 +/- 13 .6 sec). In sitting and standing positions hemoglobin oxygenation in t he skin of the lower limb was markedly reduced in patients, but normal perfusion conditions were restored in supine position, indicating rev ersibility of the changes. Reflection oxymetry seems a valuable tool f or the assessment of chronic venous insufficiency. The substantially r educed oxygenation of dermal hemoglobin in standing patients may contr ibute to the development of venous ulcers. (C) 1996 Academic Press, In c.