Although finger temperature feedback has been used to produce digital vasodilation in normal persons and those with Raynaud's disease, the mechanism and site of this effect have not been studied. In the present investigation, feedback-induced vasodilation was attenuated by brachial artery infusions of propranolol in infused, but not contralateral, hands and was not affected by digital nerve blockade. Quantitative measurements of finger blood flow demonstrated that this vasodilation occurred in arteriovenous shunts in normal persons and in the finger capillary bed in those with Raynaud's disease. Raynaud's disease patients who received finger temperature feedback reported 80 fewer percent symptoms 1 and 2 years after treatment and retained the ability to increase finger temperature and capillary blood flow at these times. These effects were not shown by patients given autogenic training, a relaxation procedure.
Using a combination of environmental and local cooling, we induced vasospastic attacks of Raynaud's phenomenon in nine of 11 patients with idiopathic Raynaud's disease and in eight of 10 patients with scleroderma. Attacks were defined as occurring if two of the possible three color changes (pallor, cyanosis, and rubor) occurred, and serial photographs were scored by three independent raters. Two fingers on one hand were anesthetized by local injection of lidocaine, and the effectiveness of nerve blocks was verified by plethysmography. The frequency of vasospastic attacks in nerve-blocked fingers was not significantly different from that in the corresponding intact fingers on the contralateral hand. These findings show that the vasospastic attacks of Raynaud's disease and phenomenon can occur without the involvement of efferent digital nerves and argue against the etiologic role of sympathetic hyperactivity.
The use of this technique for diagnosing pneumocystis pneumonia does not seem to be widely known in Great Britain, and we were unaware of its use in such cases until it was brought to our attention by Dr C Danel from Paris. Its use was first described in 1974 by Drew et all using a catheter and later by Kelly et a12 and Even et al3 using a fibreoptic bronchoscope. The success rate seems to be almost 1000% with no false positives. The lavaged fluid is centrifuged, and the cells stained with methenamine silver stain, which shows the pneumocysts clearly. We have used the technique in one suspected case, and it was gratifying to be able to have a definite positive result within three hours of the bronchoscopy. Lung biopsy samples taken at the same time eventually were also positive, but in future we plan not to run the small, but appreciable, risk of transbronchial biopsy in such cases.
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