Algodystrophie de la main, un test diagnostique precoce: Le dosage de la pression veineuse d'oxygene

Introduction: The clinical diagnosis of hand algodystrophy is usual, but a confirmation by bone scan in the early stage of the disease is classical. We propose a new test based on the measurement of the oxygen venous pressure. Method: Two series have been studied, a retrospective one, 15 patient included from 1980 to 1985, and a prospective serie, 21 patients included from 1991 to 1996. There are 22 females and 14 males. Blood samples were obtained from the normal and the algodystrophic hands. The oxygen pressure has been tested and the difference calculated. In the prospective serie the oxygen saturation in the dorsal vessels was also measured. The results were studied depending on the delay since the initial creating factor. X rays and bone scans were done for some patients. Statistical evaluation is supported by the F test for each series and the Pearson test to compare the two series. Results: In the retrospective series only the difference between the oxygen pressure in the normal and the pathologic hands was reported. The mean difference is: 15.78 mmHg ± 3.69 (1.25 to 43.5), p < 0.01. The average figures of the prospective serie are the following: - algodystrophic hand: 9.19 kpascal ± 1.20 (2.45 to 24.08 kpascal); - normal hand: 5.96 kpascal ± 0.48 (3.01 to 10.1 kpascal); - difference: 3.22 kpascal ± 1.01 (2.13 to 15.02 kpascal) (p < 0.01). In the serie of the oxygen saturation in the vessels is as follows: - algodystrophic hand: 82.38% ± 4.63; - normal hand: 71.46% ± 4.87; - difference: 10.91% ± 3.33 (p < 0.01). The more significant differences are noticed in the first 4 months following the initial aggression. X rays, when done, are normal in fifty per cent of the time. Bone scans are usually positive. Discussion: In the reflex sympathetic dystrophic hand, there is an increasing venous oxygen pressure. Sonneveld reported lower than normal transcutaneous PO₂ values. Christensen demonstrated an increase in subcutaneous blood flow. That means that an arterio-venous shunting of blood exists in the affected hand, so the capillary pressure increases, edema and peripheral ischemia occurs.