Laser Doppler imaging of skin blood flow for assessing peripheral vascular impairment in hand-arm vibration syndrome

The objective of this study was to evaluate the usefulness of laser Doppler imaging (LDPI) of the skin blood flow for assessing peripheral vascular impairment in the hand-arm vibration syndrome (HAVS). The subjects were 46 male patients with HAVS, aged 50 to 69 yr, and 31 healthy male volunteers of similar age as controls. A cold provocation test was carried out by immersing a subject's hand on his more severely affected side into cold water at a temperature of 10 degrees C for 10 min. Repeated image scanning of skin blood flow of the index, middle, and ring fingers was performed every 2 min before, during, and after the cold water immersion using a PMI-II laser Doppler perfusion imager. The mean blood perfusion values in the distal phalanx area of the fingers were calculated on each image. The patients suffering from vibration-induced white finger (VWF, n=20) demonstrated significantly lower skin blood perfusion at each interval of the test as compared with those without VWF (n=26) and the controls (p<0.01, ANOVA). The blood perfusions in the HAVS patients were associated with the severity of the symptoms as classified by the Stockholm Workshop scale for vascular staging. When a subject was considered to be positive if any of the tested fingers showing a decreased blood perfusion and/or a delayed recovery pattern, the sensitivity was 80.0%, and the specificity was 84.6% and 93.5% for patients without VWF and the controls, respectively. These results suggest that the LDPI technique could provide detailed and accurate information that may help detect the existence of impaired vascular regulation to cold exposure in the fingers of workers exposed to hand-transmitted vibration.     

A Cross Sectional Study on Hand-arm Vibration Syndrome among a Group of Tree Fellers in a Tropical Environment

This study aimed to explore the clinical characteristics of hand arm vibration syndrome (HAVS) in a group of tree fellers in a tropical environment. We examined all tree fellers and selected control subjects in a logging camp of central Sarawak for vibration exposure and presence of HAVS symptoms utilizing vibrotactile perception threshold test (VPT) and cold water provocation test (CWP). None of the subjects reported white finger. The tree fellers reported significantly higher prevalence of finger coldness as compared to the control subjects (OR=10.32, 95%CI=1.21–87.94). A lower finger skin temperature, longer fingernail capillary return time and higher VPT were observed among the tree fellers as compared to the control subjects in all fingers (effect size >0.5). The VPT following CWP of the tree fellers was significantly higher (repeated measures ANOVA p=0.002, partial η²=0.196) than the control subject. The A (8) level was associated with finger tingling, numbness and dullness (effect size=0.983) and finger coldness (effect size=0.524) among the tree fellers. Finger coldness and finger tingling, numbness and dullness are important symptoms for HAVS in tropical environment that may indicate vascular and neurological damage due to hand-transmitted vibration exposure.     

Preliminary study on the assessment of peripheral vascular response to cold provocation in workers exposed to hand-arm vibration using laser Doppler perfusion imager

Measurements of changes in finger skin blood flow with laser Doppler perfusion imaging (LDPI) in response to cold provocation test (10 degrees C, 10 min) were performed in 12 men suffering from vibration induced white finger (VWF) and 13 exposed controls. The mean perfusion values in both groups reduced markedly as a result of immersion of the hand in cold water. In the controls, however, the mean value increased gradually until the end of the cold provocation, while that in the VWF subjects remained at the lowest level. After removal of the hand from the cold water, the skin blood perfusion in the controls recovered rapidly and nearly reached the baseline value. In the VWF subjects, it had a slight increase immediately following the cold immersion but no tendency to rise as the time span increased. Analysis of covariance controlling for possible confounders revealed that the VWF subjects had significantly lower perfusion values compared to the controls in the last several minutes of the cold provocation and the following recovery. These findings suggest that the LDPI technique enables visualizing and quantifying the peripheral vascular effects of cold water immersion on the finger skin blood perfusion and thus has the potential of providing more detailed and a&curate information that may help detect the peripheral circulatory impairment in the fingers of vibration-exposed workers.     

Diagnosis of vascular injuries caused by hand-transmitted vibration

Objective

For a reliable objective diagnosis of vascular injuries in hand-arm vibration syndrome (HAVS), the standardized cold provocation tests—finger skin temperature measurement during hand(s) immersion in cold water (FST test) and finger systolic blood pressure measurement during local cold exposure (FSBP test)—are widely used. In recent years there is a growing controversy regarding the diagnostic value of these tests. The aim of this study was to describe particularly the diagnostic performance of FST and FSBP tests, and also to focus on the problems and uncertainties regarding the test conditions and results, in the laboratory diagnosis of vascular injuries caused by hand-transmitted vibration.

Method

A review of pertinent published English- and Japanese-language articles and conference proceedings (between 1976 and 2006) was conducted.

Results

From the reports with regard to diagnostic significance of the FSBP test, it seems to be an important laboratory test for diagnosing vibration-induced white finger (VWF). On the other hand, despite a large number of research studies with the FST test, there is a lack of data for the standardized FST test, which can confirm the value of it in diagnosing VWF. Moreover, there is no agreement on effective parameter/s to quantify and compare the responses in FST induced by immersion in cold water. While assessing and staging vascular injuries in HAVS, inquiry regarding finger coldness appears to be useful.

Conclusions

As there is no single test with satisfactory diagnostic ability for VWF, at present it is reasonable to use the cold provocation tests as a part of the comprehensive approach to evaluate HAVS patients. In addition to the objective methods, the index of finger coldness may be useful while diagnosing the vascular component of HAVS.

     

Circulatory disturbances of the foot in vibration syndrome

Summary Circulatory disturbances of the foot in patients with vibration syndrome were studied by measuring the skin temperature of both index fingers and great toes through a 3-min immersion of the right foot in cold water at 10°C. Subjects included 11 patients with vibration-induced white finger (VWF) [VWF(+) group], 12 patients without VWF [VWF(–) group], and 20 healthy referents not exposed to vibration. Patients were all male chain saw operators who had scarcely been exposed to vibration of the foot. The prevalence of coldness felt in the upper and lower extremities was > 90% in the VWF(+) group, about 60% in the VWF(–) group, and < 10% in the referents. The extent of the coldness was greatest in the VWF (+) group. The skin temperature of both fingers and toes was lowest in the VWF(+) group, somewhat higher in the VWF(–) group, and highest in the referents both before and after immersion. These findings indicate that patients with vibration syndrome, especially those with VWF, have circulatory disturbances in the foot as well as in the hand. The disturbances in the foot may be related to long-term repeated vasoconstriction in the foot induced by hand-arm vibration through the sympathetic nervous system.     

A four-year follow-up study on subjective symptoms and functional capacities in workers using hand-held grinders.

Fifty-three grinders in the metal industry were re-examined 4 years after their first examination. Information about age, occupation, daily vibration exposure, drinking and smoking habits, and presence of subjective symptoms such as vibration-induced white finger (VWF), and numbness and pain in the fingers was collected during the first and second examination. Cold provocation test (10 degrees C/10 min) was also employed to evaluate disturbances in the peripheral circulatory and peripheral nerves in all subjects. The frequency-weighted vibration acceleration of various types of hand-held tools was measured. There was no subject with VWF at the first examination; however, during the course of follow-up, two cases (3.8%) of VWF with latent interval of more than 25 years were diagnosed. Prevalence of numbness in the fingers and shoulder stiffness was significantly higher at the second examination. When the prevalence of subjective symptoms was tested by the subjects' total operating time (TOT) during the 4-year follow-up period, those whose TOT was equal to or more than 2500 hours showed higher prevalence compared to the other subgroup. The paired values of recovery rate of finger skin temperature and vibration sensation threshold after the cold water immersion test were significantly different at the first and second examination. On average, the diminution of hand-grip force during the 4-year follow-up course was 7.4%; the difference being significant at 0.01 level. Significant differences in the paired data of pinching power and tapping ability could be detected. The frequency-weighted vibration acceleration of various tools was in the range of 1.1-4.6 m/s2. It was concluded that: (1) prolonged occupational exposure to the vibration of hand-held grinding tools should be considered as a risk factor causing disturbances in the hand-arm system of the operators; (2) the results of recovery rate of finger skin temperature and the vibration sensation threshold seemed to be appropriate indicators for the assessment of peripheral vascular and peripheral nerve disturbances in workers exposed to hand-arm vibration; and (3) to reduce the subjects' physical stress, attention should be paid to ergonomic factors.     

Tests employed in Japan for the investigation of peripheral circulatory disturbances due to hand-arm vibration exposure

Tests for the investigation of peripheral circulatory function are thought, in Japan, to be of primary importance for the proper diagnosis of the hand-arm vibration syndrome. The complaints presented in connection with Raynaud's phenomenon (finger skin blanching, numbness, cold sensation, and pain in the hands) should be thoroughly assessed. In evaluating the results of skin temperature measurements and the nail compression test before and after cold provocation by immersion of the hands in cold water, seasonal and diurnal variation, as well as differences in room temperature, temperature of the cooling water, duration of cooling time, etc, must be taken into account.     

Occupational hand–arm vibration syndrome in Korea

Objectives: It is suspected that there is a large number of patients suffering from hand–arm vibration syndrome (HAVS) in Korea. However, no cases have been reported since 1992. This study was conducted to identify HAVS cases and determine the characteristics of the syndrome. Methods: In April 2001, the Busan, Ulsan, and Gyeong-Nam Province Occupational Disease Surveillance System (BUGODSS) was established to identify work-related HAVS and other occupational diseases. In the 2 years of this project, occupational physicians from five hospitals in these provinces collected information by way of interviews and questionnaires during mandatory occupational medical examinations. Among the initial 189 suspected HAVS cases, 58 volunteers were given cold-water provocation tests in order to diagnose the vascular component of the disorder. Results: One hundred fifty-four approximately occupational HAVS cases were identified from ca. 21,000 workers. One hundred fifty about of these cases were male. The cases were most often found in workers from the shipbuilding industry, and the grinder was the most common source of vibration exposure. Cases of sensorineural disorder (SD) were more common than cases of vascular disorder (VD). The mean values of the finger skin temperature and its recovery rate at 5 min and 10 min after cold-water provocation were significantly lower in the group with the VD than in the group with the SD. Conclusions: We identified 154 occupational HAVS cases, although no cases have been reported during the occupational medical examinations mandated by the state. The majority of the cases were in workers that used grinders in the shipbuilding industry. We determined that peripheral VD and peripheral SD can progress independently of each other. We conclude that exposure to hand-transmitted vibration (HTV) and HAVS cases are common in shipbuilding industry in Korea. The recovery rate of finger skin temperature after cold-water provocation is one of the useful methods for diagnosing the vascular component of HAVS.     

Cold provocation test results from a 1985 survey of hard-rock miners in Ontario

A total of 143 miners, 6 ex-miners, and 42 referents from five mines in northern Ontario were examined with a cold provocation test. The skin temperatures, measured by thermocouples at the tips of the fingers and thumbs were recorded at 5-s intervals throughout the immersion in cold water (10 degrees C) for 10 min and during the recovery period. The finger skin temperature was followed until 99% recovery had occurred as compared to the starting temperature. For the referents and the vibration-exposed subjects, the results by separate stage of the Taylor-Pelmear scale for hand-arm vibration syndrome were compared. There were statistically significant differences in the mean finger temperature at the 50, 75, 90, and 95% recovery times between stages 0, 0T/0N, and stages 1 through 3 combined, as well as significant differences between stages 1, 2, and 3. The mean temperature at 10 min and the mean hyperemia temperature for eight fingers combined were compared between the miners and referents. There were significant differences in the mean temperature at 10 min and in the hyperemia temperature between the referents and miners in stage 0T/0N, as well as between the referents and the miners in stages 1 through 3 combined. For the worst finger (defined as that with the lowest temperature at 10 min) there was an increasing trend towards a lower hyperemia temperature and delay in recovery time from stage 0 to stages 2 and 3 combined.(ABSTRACT TRUNCATED AT 250 WORDS)     

Different conditions of cold water immersion test for diagnosing hand-arm vibration syndrome

The cold water immersion test with finger skin temperature (FST) measurement is used to assess vascular disorders in hand-arm vibration syndrome (HAVS). The test method is currently being standardized within the International Organization for Standardization (ISO) in which a water temperature of 12°C for 5 min of hand immersion and an option of using a waterproof hand covering during immersion are proposed. It is necessary to evaluate the diagnostic significance of the test with FST measurement under different conditions to provide a proper management of HAVS patients. The aim of this article is to review research findings of this test with FST measurement and discuss test conditions influencing the results and diagnostic significance. Different conditions were employed, and the test results were shown to be influenced by water temperature, immersion time and other conditions such as room temperature, season, ischemia during immersion, and evaluation parameters. These factors need to be considered in the standardization of the cold water immersion test with FST measurement. It has been mentioned that a high water temperature, a short immersion time and other conditions should be chosen to expose a subject to minimal suffering during the test. A water temperature between 10°C and 15°C and a 5 min immersion might be suitable for the cold water immersion test. The reported sensitivity and specificity evaluating rewarming to the initial temperature for the test using a water temperature of 12°C and a 3 min immersion are 58% and 100%, respectively; these are low but similar to those for tlie water immersion test at 10°C. Therefore, the proposed cold water immersion test at 12°C for 5 min by the ISO (Draft International Standard) is the focus of much interest, and further studies are needed to obtain sufficient data for evaluating the diagnostic significance of the test. At present, the test needs to be used together with a test battery.     

Validity of function tests on the upper extremities in establishing a prognosis in vibration syndrome

The validity of function tests on the upper extremities as prognostic tools in vibration syndrome was evaluated over a sequence of observation periods. The subjects examined were 672 forest workers using chain saws who had had some complaints and who had shown abnormal findings in the function tests. The function tests consisted of peripheral circulatory and sensory tests, including cold provocation and motor tests of functional capacity in the upper extremities. From the results of testing, 23 variables were selected and examined by multivariate analysis. The four principal components were extracted by principal component analysis, and the factor score of the peripheral circulatory disturbances component was found to be highly correlated with the severity of VWF (Vibration-induced White Finger). The course of VWF and the nail compression test had high standard regression coefficients with the severity of vibration syndrome. The course of finger numbness, pinching power, pain threshold, skin temperature and X-ray findings in the elbow joints had high discriminant function values for the evaluation of the severity of vibration syndrome.     

Interpretation of the finger skin temperature response to cold provocation

Objectives: To compare alternative methods of interpreting the response of finger skin temperature (FST) to cold provocation for the detection of the abnormal cold response observed in vibration-induced white finger (VWF). Method: The FST response to cold provocation was measured in 36 male subjects: 12 office workers, 12 manual workers and 12 manual workers with symptoms of VWF. The FSTs were monitored continuously on the distal phalanges of all five fingers of a test hand for 2 min before, for 5 min during, and for 10 min following, immersion of the test hand in water at 15 °C. Of the fingers investigated, 147 were reported not to exhibit blanching and 33 were reported to exhibit blanching. Twenty-one alternative methods of interpreting the response of FSTs to cold provocation were assessed. These were grouped as: (1) areas above the response profile (i.e. the area above the curve showing the FSTs as a function of time during cooling and recovery), (2) areas below the response profile, (3) absolute temperatures during and following cold provocation, (4) percentage differences in FSTs, (5) the times taken for FSTs to rise by specified amounts and (6) rates of change of FSTs. Differences in the response to cooling between those fingers reported to blanch and the fingers not reported to blanch were tested, and receiver operating characteristics (ROCs) were used to compare the sensitivity and specificity of the various measures to symptoms of VWF. Results: The areas above the response profile, areas below the response profile, percentage FSTs, absolute FSTs and rates of change of FSTs tended to discriminate between healthy and unhealthy subjects on a group basis. However, some of these methods of interpreting the FST response to cold provocation did not show a high sensitivity or specificity to vascular dysfunction on individual fingers. The area above the response profile, the percentage of initial temperature at the fifth minute of recovery and the maximum temperature during the 10-min recovery period, were found to show the highest sensitivity and specificity to symptoms of vascular dysfunction. Conclusions: The method chosen to interpret the FST response to cold provocation affects the ability of the test to detect an abnormal cold response. The area above the response profile, the percentage of initial temperature at the fifth minute of recovery and the maximum temperature achieved during a 10-min recovery period appear to be the most suitable measures for monitoring vascular function in workers exposed to hand-transmitted vibration. It is suggested that the FST response to cold provocation should be interpreted with respect to the state of initial blood flow. Received: 12 June 2000 / Accepted: 28 December 2000     

The diagnostic value of finger systolic blood pressure and cold-provocation testing for the vascular component of hand-arm vibration syndrome in health surveillance

BACKGROUND: Hand-arm vibration syndrome (HAVS) is a complex condition with vascular, sensorineural and musculoskeletal components. A number of quantitative tests have been used for assisting in the diagnosis of HAVS and grading disease severity. AIMS: To investigate and compare the diagnostic value of finger systolic blood pressure (FSBP) and rewarming of finger skin temperature (FST) following cold-provocation testing, in the assessment of vascular HAVS. METHODS: Twenty-four individuals with vascular HAVS (Stockholm Workshop stage 2 or 3V) and 22 control subjects underwent FSBP measurements at 30, 15 and 10 degrees C and monitoring of FST following immersion of the hands in water at 15 degrees C for 5 min. RESULTS: There was a significant reduction in median FSBP% in the vascular HAVS group in the change in FSBP from 30 to 15 degrees C adjusted for brachial blood pressure (FSBPC%). There was no difference in the median time for FST to rewarm by 4 degrees C between HAVS cases and controls. The sensitivity and specificity of FSBP to discriminate between the groups varied between 44 and 61% and 91 and 95%, respectively. The sensitivity and specificity for the time for FST to rewarm by 4 degrees C were 71 and 77%. CONCLUSIONS: There is little evidence that the described form of finger rewarming after cold-provocation testing is a useful diagnostic test for vascular HAVS, although it may have some moderate influence in ruling out vascular problems. Based on our data, the FSBP may also have limited use in confirming a positive diagnosis of vibration-induced vascular problems. The higher specificity of the FSBP test suggests it may have some value in ruling out the vascular component of HAVS. The data from this study do not confirm the diagnostic power of FSBP for the vascular component of HAVS reported by a few other investigators.     

A 4 degrees C-1 min method of cold water immersion test for peripheral circulatory function in fingers]

To assess the validity of a new simplified cold water immersion test (4 degrees C-1 min method) for peripheral circulatory function, comparison was made with the conventional method (10 degrees C-10 min method). These two different methods of cold immersion test were applied to 23 patients with vibration disease and 24 healthy men. Observation was made on finger skin temperature by a thermistor and complaints in the hand by a 5-step self-reported scale method every minute during the test. The patterns of recovery of skin temperature after cold immersion in each group were similar in both methods. Pain in the hand in the 4 degrees C-1 min method was less than that in the 10 degrees C-10 min method. The recovery rate at 5 min in the patients with Raynaud's phenomenon was lower than that in those without Raynaud's phenomenon in the 4 degrees C-1 min method (p < 0.01). However, no significant differences were noted in 10 degrees C-10 min method. The results suggest that the new method is feasible in detecting the response of vasodilation after immersion. In the recovery rate at 5 min after immersion, near values of the sensitivity and specificity were observed between 50% cut-off values in the 4 degrees C-1 min method and 30% value in the 10 degrees C-10 min method. Thus, the 4 degrees C-1 min method is considered to be more useful to evaluate the physiological response after cold immersion than the 10 degrees C-10 min method.     

Seasonal variation of circulatory and sensory functions during immersion test in cold water

For early diagnosis of vibration syndrome, peripheral circulation and sensory tests after cold water immersion of the upper extremities are being performed widely in Japan. The authors studied the seasonal effect on the immersion test and its influence on diagnosis of vibration syndrome. Eight healthy male subjects, aged from 28 to 39, were examined. The immersion tests were conducted in winter (February), spring (May), summer (August) and autumn (November) in Ube city, Japan (Table 1). The room temperatures were maintained at 10 degrees C, 20 degrees C and 30 degrees C during the tests at each season. As to the exposure-to-cold test, the left hand of subject was immersed in stirred water at 10 degrees C for ten minutes, and the changes of peripheral circulatory function and sensory function were measured. Peripheral circulatory function was assessed by the skin temperature of middle finger and the value of the nail press test on the index finger. Sensory function was assessed by 125 Hz vibratory sense threshold and pain threshold of the middle finger. The finger skin temperature was lower in autumn and winter, followed by spring, and highest in summer. In particular, the finger skin temperature in autumn was lower than that in winter at the condition of room temperature at 30 degrees C, which is considered to be less effected by heat content in the body (Fig. 1, Table 3). The frequency of the appearance of cold induced vasodilation was also lower in autumn than that in winter (Table 2). These findings suggest that the tonus of the vasoconstrictor in the skin vessels of finger is strongest in autumn, followed by winter. It is also suggested that the tonus remains slightly strong in spring and is weakest in summer. Furthermore, the seasonal variations in the value of the nail press test, vibratory sense threshold and pain threshold were observed at some points of measuring time during immersion test (Figs. 2-4). Of these, the variations in the value of the nail press test and vibratory sense threshold were considered to be secondary to the seasonal variation of peripheral circulatory function (Fig.6). The variation in pain threshold was considered to result from paresthesia developing in the lower room temperature at 10 degrees C. The pain of finger during immersion test was also effected by season but the range of variation was not significant (Fig.5).(ABSTRACT TRUNCATED AT 400 WORDS)     

The effect of aging on the peripheral functions in farmers and chain saw operators. Part 2. Age-related changes in skin temperature and hyperemia time after pressing the nail (author's transl)

Vibration hazards which arise after exposure to mechanical vibration comprise various types of disorders, the most common of which are peripheral circulatory disturbances. It is now well recognized that aging effects all organ systems of the human body. The present study was therefore performed to assess the effects of aging on finger skin temperature and on hyperemia time after pressing the nail, both of which reflect peripheral circulatory functions. The subjects were 88 farmers and 86 chain saw operators ranging in age from 30 to 69 years, and 27 healthy persons aged 21 to 37 years as controls. Data were evaluated before and after cold water immersion tests in which the hand was immersed in 10 degrees C water for 10 minutes. The results obtained were as follows: 1) Before the test, skin temperature was negatively correlated with age, and hyperemia time was positively correlated with age in both farmers and chain saw operators but not in the case of the control subjects. 2)The skin temperature became lower, and hyperemia time grew longer with advancing age in both farmers and chain saw operators before and after the immersion tests. In comparison of the average skin temperature and hyperemia time between farmers and chain saw operators classified by age, the average skin temperature in chain saw operators was significantly lower than that in farmers, and the average hyperemia time in chain saw operators was significantly longer than that in farmers of every age group after the immersion test. The results suggest that we should take age-related changes into consideration to some degree when we evaluate the finger skin temperature and hyperemia time in diagnosing peripheral circulatory disturbances.     

Development of an improved system for monitoring the peripheral circulation and its application. Part 2. Its application to the cold water immersion test in workers using vibratory tools

Using an improved system for measuring skin blood flow by the thermal clearance curve, the change of the skin blood flow in the finger (finger blood flow) of the workers using vibratory tools induced by 10 degrees C cold water immersion for 10 min was observed in order to clarify the pathogenesis of vibration-induced white finger (VWF) from the aspect of peripheral circulatory function and simultaneously to demonstrate the efficiency of the system. The subjects constituted a group of 10 workers with VWF (VWF group) and 10 healthy workers without a history of hand-arm symptoms (control group). Ages and years of exposure to vibration in the two group were almost equal. The results were as follows. 1) While the finger blood flow in the control group was remarkably decreased at 1 min after the immersion, the decrease in the VWF group was low as compared with that in the control group. This result shows that vasoconstriction just after the immersion in VWF patients is not as great as that in the control group. 2) The finger blood flow in the control group at 5 min after the immersion was increased. In contrast no increase in the VWF group was observed. These results showed that cold-induced vasodilatation (CIVD) in VWF patients diminished. 3) An increase of the finger blood flow at 1 min after stopping the immersion was observed in the VWF group. These results suggest that the property of reaction to cold in VWF patients is not excessive vasoconstriction as has been hypothesized, but the diminution of CIVD. Apart from 10 workers of VWF group, observing the change of the finger blood flow in a case in which VWF was provoked by the immersion, the author found an abnormal decrease of the finger blood flow at 5 min after the immersion. This finding supports the hypothesis that the diminution of CIVD plays an important role in VWF attack as well. Concerning the characteristics of peripheral circulatory function in VWF patients, it can therefore be considered that its reaction in VWF attack is vasospasms, while the reaction to cold is the diminution of CIVD in the non-attack phase. The cold water immersion test using the system was recognized to be useful for diagnostic examination because the estimation of finger blood flows at both measuring points, 1 min and 5 min after the immersion, could fairly well discriminate VWF patients from healthy workers.(ABSTRACT TRUNCATED AT 400 WORDS)     

Physiological methods used in Japan for the diagnosis of suspected hand-arm vibration syndrome

In the pathogenesis of hand-arm vibration syndrome, vibration affects the peripheral system, especially the circulatory, nervous, and musculoskeletal systems. Medical questionnaires, physical examinations, and laboratory tests are used to diagnose the hand-arm vibration syndrome. The laboratory tests are satisfactory diagnostic aids for detecting slight disorders of the peripheral circulatory, nervous, and musculoskeletal systems. Peripheral circulatory function tests include skin temperature measured by a thermistor under specific temperature conditions, the nail compression test, and the cold provocation test (10-min immersion in cold water at 5 or 10 degrees C). To assess peripheral nervous function, tests for the pain and vibration senses are included. Peripheral musculoskeletal function tests consist of grip strength, pinch strength and tapping counts. These physiological tests are applied in worker screening twice a year. These tests have been authorized by the Ministry of Labour since 1973. Several criteria for the tests, although not authorized, are widely used. The diagnostic implication of each separate test may be low. Consequently, some laboratory tests should be evaluated, along with medical questionnaires and physical examinations, in the diagnosis of suspected hand-arm vibration syndrome.     

振动性白指—局部受冷和振动负荷后的末梢循环表现

本研究分为三个组:(1)振动白指组(29例);(2)振动无白指组(105例);(3)对照组(60例)。 研究表明:振动白指组冷水试验的白指再现率为10％,而振动无白指组和对照组无一例出现白指;Ⅰ期振动性白指患者的皮温恢复时间延长者占40％,而Ⅱ期和Ⅲ期振动白指患者皮温恢复时间延长者均为100％;振动白指组的指血流图平均波辐高度冷水试验后显著低于冷水试验前(P<0.01),而振动无白指组和对照组没有这种差异。 本文讨论上述试验在振动性白指诊断中的意义。     

Assessment of the hand-arm vibration syndrome: thermometry, plethysmography and the Stockholm Workshop Scale

BACKGROUND: The Stockholm Workshop Scale (SWS) provides a staging scheme for hand-arm vibration syndrome (HAVS) based on subjective history. Cold provocation finger thermometry and plethysmography are commonly used objective tests for the vascular component of HAVS. AIM: To examine the correlation between the cold provocation tests and SWS vascular stage. A secondary goal was to evaluate the correlation between cold provocation finger plethysmography and thermometry testing. METHODS: Patients investigated for HAVS at St Michael's Hospital, Toronto, Ontario, were subjected to the same protocol including a questionnaire, clinical assessment and objective testing. Spearman correlation coefficients were calculated for the vascular tests with the SWS and for the vascular tests themselves. Logistic regression models controlled for age, smoking, use of vasoactive medications and time since last vibration exposure. RESULTS: One hundred and thirty-nine patients investigated for HAVS consented to participate in the study. The correlation coefficients for plethysmography (rho = 0.14) and thermometry (rho = 0.18) with the SWS were not statistically significant. Plethysmography and thermometry results were significantly correlated (rho = 0.47, P < 0.001). Logistic regression showed plethysmography and thermometry to weakly predict SWS vascular stage (OR 1.5 and 1.3, respectively). None of the potential confounders had a significant effect in the models. CONCLUSION: The results of plethysmography and thermometry did not significantly correlate with SWS vascular stage in this study. The objective tests did correlate with each other, suggesting that they are reliable measures of similar phenomena likely related to underlying vascular pathology.