Raynaud's phenomenon in forestry workers in Quebec.

A survey of 1540 forestry workers in Quebec found a prevalence of Raynaud''s phenomenon of 30.5% among chain-saw users and 8.7% among nonusers. Prevalence was related directly to duration of use of the chain-saw. The mean interval (+/- the standard deviation) between the time the chain-saw was first used and the onset of Raynaud''s phenomenon was 7.8 +/- 5.6 years. After 20 years of chain-saw use over 50% of the population had Raynaud''s phenomenon. Relative risks among those using a chain-saw for more than 10 years were 3.60 for nonsmokers and 6.55 for smokers. Other factors associated with the phenomenon included a family history of nonoccupational Raynaud''s phenomenon, previous injuries to the arms, climate and type of residence during the wood-cutting season. Decreased work capacity, interference with leisure activities and changes in professional orientation often resulted from this disease. These problems should be taken into account when disability compensation is being considered.     

Treatment of Raynaud's phenomenon by fibrinolytic enhancement.

Twenty patients with advanced Raynaud''s phenomenon, in 14 of whom it was secondary to scleroderma, were treated with stanozolol, an anabolic steroid that enhances natural fibrinolysis. All showed an increase in hand blood flow and a reduction in symptoms during treatment. This response may have been caused by the lysis of fibrin deposited in the digital arteries and the reduction of plasma viscosity. Stanozolol is a useful addition to the treatment of patients with advanced Raynaud''s phenomenon who have trophic changes.     

Raynaud's phenomenon as side effect of beta-blockers in hypertension.

A series of 102 hypertensive patients were assessed for the frequency of symptoms of Raynaud''s phenomenon and absent peripheral pulses. Out of 21 patients receiving methyldopa alone only one had cold hands and feet whereas among patients on beta-blockers the incidence was 50%. The frequency of both symptoms and absent pulses was highest in patients taking propranolol compared with those taking atenolol or oxprenolol. Patients without a foot pulse were much more likely to have cold hands. A change from propranolol to oxprenolol in some symptomatic patients resulted in improvement. In two patients the skin temperature fell after an 80-mg dose of propranolol. The mechanism by which beta-blockers induce Raynaud''s phenomenon is still not clear.     

Prevalence of symptoms of Raynaud's phenomenon in general practice.

OBJECTIVE--To investigate the prevalence of Raynaud''s phenomenon in the populations of five general practices. DESIGN--Two populations studied. A questionnaire was given to all new patients attending five general practices over four weeks, and the same questionnaire was sent by post to a random sample of adults from two of the practices. SETTING--General practices in inner London, Merseyside, and Cheshire. SUBJECTS--1532 Patients who completed questionnaires (1119 who attended the surgeries (response rate unknown) and 413 respondents to the postal survey (response rate 69%)). MAIN OUTCOME MEASURES--Response to questionnaire on symptoms of Raynaud''s phenomenon: patients were regarded as having the disease if they had episodes of blanching of the fingers that were precipitated by cold and accompanied by sensory symptoms (pins and needles or numbness). Subsequent interview and clinical appraisal of patients with the disease according to their responses to the questionnaire. RESULTS--The prevalence of Raynaud''s phenomenon was 11% (26/231) and 19% (34/182) respectively in men and women who completed the postal questionnaire and 16% (56/357) and 21% (157/762) respectively in those who completed the questionnaire when attending their general practice. Thus the overall rates were slightly higher in women, but there was no effect of age even after adjustment of the rates for practice and method of survey. CONCLUSION--The prevalence of Raynaud''s phenomenon is high compared with the low number of patients who seek treatment for the disease.     

Exaggerated muscle mechanoreflex control of reflex renal vasoconstriction in heart failure.

In heart failure (HF) patients, reflex renal vasoconstriction during exercise is exaggerated. We hypothesized that muscle mechanoreceptor control of renal vasoconstriction is exaggerated in HF. Nineteen HF patients and nineteen controls were enrolled in two exercise protocols: 1) low-level rhythmic handgrip (mechanoreceptors and central command) and 2) involuntary biceps contractions (mechanoreceptors). Renal cortical blood flow was measured by positron emission tomography, and renal cortical vascular resistance (RCVR) was calculated. During rhythmic handgrip, peak RCVR was greater in HF patients compared with controls (37 +/- 1 vs. 27 +/- 1 units; P < 0.01). Change in (Delta) RCVR tended to be greater as well but did not reach statistical significance (10 +/- 1 vs. 7 +/- 0.9 units; P = 0.13). RCVR was returned to baseline at 2-3 min postexercise in controls but remained significantly elevated in HF patients. During involuntary muscle contractions, peak RCVR was greater in HF patients compared with controls (36 +/- 0.7 vs. 24 +/- 0.5 units; P < 0.0001). The Delta RCVR was also significantly greater in HF patients compared with controls (6 +/- 1 vs. 4 +/- 0.6 units; P = 0.05). The data suggest that reflex renal vasoconstriction is exaggerated in both magnitude and duration during dynamic exercise in HF patients. Given that the exaggerated response was elicited in both the presence and absence of central command, it is clear that intact muscle mechanoreceptor sensitivity contributes to this augmented reflex renal vasoconstriction.     

Raynaud's phenomenon and thermal entrainment: an objective test.

A new objective test for diagnosing Raynaud''s phenomenon was assessed in practice. The test is based on entrainment of the thermal vasomotor control system and entails non-invasive measurement of blood-flow responses in one hand while alternating thermal stimuli are applied to the contralateral hand. A significant (p less than 0.001) abnormality of vasomotor control was found in patients with Raynaud''s phenomenon compared with normal subjects. When applied clinically this test is diagnostic and indicates the severity of the disease and the effect of treatment.     

Biofeedback treatment of Raynaud's disease and phenomenon

Six Raynaud's disease and four Raynaud's phenomenon patients were treated with 12 sessions of finger temperature biofeedback. The mean frequency of vasospastic attacks was reduced to 7.5% of that reported during the pretreatment baseline and was maintained for a 1 year follow-up period. Significant control of digital temperature was demonstrated during laboratory training sessions. Raynaud's phenomenon patients showed significantly greater temperature increases during feedback periods than Raynaud's disease patients. Correlations between finger temperature and other physiological measures suggested that results could not be attributed to general physical relaxation. The role of imagery in self-control of digital temperature is considered.Portions of this paper were presented at the annual meeting of the Biofeedback Society of America, Albuquerque, March 1978.     

Thermal entrainment methods for studying Raynaud's phenomenon

Entrainment occurs when an externally applied periodic temperature stimulus forces the peripheral bloodflow component of thermoregulation to oscillate at the same frequency. This phenomenon can be demonstrated using frequency transforms to analyse the spectral content of the bloodflow, and can be used as a diagnostic test for Raynaud's phenomenon. Correlations were performed between the clinical diagnosis and the objective tests. The average inter-clinical correlation coefficient was r = 0.66. When the average clinical diagnosis was compared with a combination of thermal entrainment and digital patency testing the correlation coefficient rose to r = 0.68. These results highlight the difficulties encountered when assessing patients with Raynaud's phenomenon and the necessity of applying both physiological and clinical techniques.     

Oral L-arginine can reverse digital necrosis in Raynaud's phenomenon

Raynaud's phenomenon is characterized by transient reduction in blood supply through the small arteries in the hands and feet. Severe Raynaud's phenomenon can cause digital necrosis. It has been hypothesized that nitric oxide may have a role in Raynaud's phenomenon. We report two cases in which oral L-arginine reversed digital necrosis in Raynaud's phenomenon and two additional cases in which the symptoms of severe Raynaud's phenomenon were improved with oral L-arginine. These reports suggest that a defect in nitric oxide synthesis or metabolism is present in Raynaud's phenomenon. They also suggest a potential role for oral L-arginine therapy in Raynaud's phenomenon, especially in Raynaud's phenomenon with digital necrosis.     

Treatment of Raynaud's phenomenon with ketanserin in patients with connective tissue disorders.

The serotonin receptor blocker ketanserin was given orally in a double blind crossover study to 10 patients with connective tissue disorders and Raynaud''s phenomenon. Eight of the 10 patients improved clinically on ketanserin and none on placebo. Digital blood flow was assessed with laser Doppler flowmetry (LDF), photoplethysmography, and skin temperature measurements. Laser Doppler flowmetry was the most useful method, showing a significant reduction in recovery time after a standard cold provocation. Although the resting flow was not significantly improved, digital ulcers healed in four out of five patients, providing evidence of increased nutritive flow. The results of this study suggest that orally administered ketanserin may be an effective and well tolerated treatment for Raynaud''s phenomenon associated with connective tissue disorders, especially scleroderma.