Tissue hypoxia in complex regional pain syndrome.

Untreated complex regional pain syndrome (CRPS) may progress from acute stages with increased hair and nail growth in the affected limb to chronic stages with atrophy of the skin, muscles and bones. The aim of this study was to investigate whether tissue hypoxia could be one mechanism responsible for this late CRPS symptoms. Nineteen patients with CRPS and two control groups (healthy control subjects, surgery patients with edema) participated in this study. Skin capillary hemoglobin oxygenation (HbO(2)) was measured non-invasively employing micro-lightguide spectrophotometry (EMPHO). The EMPHO probe was mounted force-controlled onto the skin of the affected and unaffected hand. HbO(2) was m…