A medical assessment process for a large volume of medico-legal compensation claims for hand-arm vibration syndrome

BACKGROUND: The judgement on preliminary issues of nine lead cases of suspected hand-arm vibration syndrome (HAVS) in former coal miners in the UK ruled that there was evidence of damage and breach of duty of care (Armstrong and Others v. British Coal, 1996). In anticipation of > 120 000 cases and at significant cost, a handling agreement was prepared in 1999. This recommended a single medical assessment process (MAP) to determine general damages for which almost 200 doctors attended 2 days of training. AIMS: This paper outlines the assessment process and the results to date. METHODS: Seventeen test centres across the UK were commissioned. Standardization of the performance by both the doctors and technicians within individual examination centres and across all centres was necessary. A pragmatic solution using 'best available assessment techniques', whilst at the same time coping with the large number of claimants, was required. Doctors were trained to administer questionnaires for clinical symptoms, past medical history and occupational history, and a standardized clinical assessment pro-forma. Three standardized tests were used: vibrotactile thresholds, thermal aesthesiometry and cold water provocation testing. A modification of the Stockholm Workshop Scales and scoring system was adopted. At time of writing, 52 490 claimants had been assessed by the MAP. RESULTS: Analysis of results showed that 5% were assessed at 0SN, 15% at 1SN, 18% at 2SN (early), 28% at 2SN (late), 33% at 3SN, 21% at 0V, 13% at 1V, 38% at 2V and 28% at 3V. CONCLUSION: It is concluded that the MAP is a practical and time-efficient tool for assessing a large volume of claimants with suspected HAVS. Further analysis of the process and staging is required to confirm its validity as a medico-legal examination.     

Thenar hammer syndrome: a case report

BACKGROUND: Raynaud's phenomenon occurs among automobile mechanics secondary to long-term use of vibrating hand-held tools. It can also occur from traumatic injury to the upper extremity. AIM: This report describes a case of single digit Raynaud's phenomenon in an automobile mechanic due to focal arterial impact trauma. CASE REPORT: A 38-year-old right-handed transmission mechanic complained of paraesthesia and blanching of the right index finger on exposure to cold and eventually developed a transient necrotic ulcer at the tip of the digit. He had a long history of occupational exposure to vibrating hand-held power tools. Evaluation for common causes of Raymond's phenomenon was negative. The diagnosis of hand-arm vibration syndrome (HAVS) was rejected because of the rapidity of progression and severity of the symptoms restricted only to the index finger without corresponding symptoms of the other digits of the right hand as would be expected. Angiography revealed an obstructive lesion of the distal right radial artery at the wrist and he was diagnosed with thenar hammer syndrome. This uncommon condition was due to focal injury of the distal radial artery caused by repeated slamming of transmission parts on a work table. CONCLUSIONS: Not all cases of Raynaud's phenomenon in workers using vibrating hand-held tools are due to HAVS. Alternative aetiologies should be considered especially if symptoms are asymmetrical and unilateral.     

Hand-arm vibration syndrome in South African gold miners

BACKGROUND: Hand-arm vibration syndrome (HAVS) is associated with the use of hand-held vibrating tools. Affected workers may experience symptoms of tingling, numbness, loss of grip strength and pain. Loss of dexterity may impair everyday activities, and potentially increase the risk of occupational accidents. Although high vibration levels (up to 31 m/s(2)) have been measured in association with rock drills, HAVS has not been scientifically evaluated in the South African mining industry. AIMS: The aim of this study was to determine the prevalence and severity of HAVS in South African gold miners, and to identify the tools responsible. METHODS: A cross-sectional study was conducted in a single South African gold-mine. Participants were randomly selected from mineworkers returning from annual leave, comprising 156 subjects with occupational exposure to vibration, and 140 workers with no exposure. Miners who consented to participate underwent a clinical HAVS assessment following the UK Health and Safety Laboratory protocol. RESULTS: The prevalence of HAVS in vibration-exposed gold miners was 15%, with a mean latent period of 5.6 years. Among the non-exposed comparison group, 5% had signs and symptoms indistinguishable from HAVS. This difference was statistically significant (P < 0.05). All the cases of HAVS gave a history of exposure to rock drills. CONCLUSIONS: The study has diagnosed the first cases of HAVS in the South African mining industry. The prevalence of HAVS was lower than expected, and possible explanations for this may include a survivor population, and lack of vascular symptom reporting due to warm-ambient temperatures.     

Effectiveness of therapy with iloprost in hand-arm vibration syndrome

AIM: To evaluate the efficacy and tolerance of therapy with iloprost in hand-arm vibration syndrome. METHODS: We describe a clinical case of a male aged 53 years, who was a heavy smoker for 30 years and a mason working with vibrating tools since 1962. He presented with a history of 10 years of attacks of vasospasm, functional impairment and digital ulceration. He was diagnosed as having hand-arm vibration syndrome vascular stage 4 on the Stockholm Workshop 1986 Scale. Besides suspension from work and abstention from smoking, we began intravenous infusion of iloprost for 6 h in cycles of 3-6 consecutive days, arriving at a dose of 1.5-2.0 ng/kg/min. RESULTS: After eight cycles, he reported significant symptomatic and functional improvement. Iloprost was seen to be efficacious: the trophic skin lesions disappeared and his microcirculatory perfusion tests improved. There were no significant side effects. CONCLUSIONS: We suggest that the use of iloprost in the treatment of the most advanced stages of vascular hand-arm vibration syndrome warrants further study     

Vibration exposure and disease in a shipyard: a 13-year revisit

BACKGROUND: In a 1988 study of shipyard workers, a progressive association was observed between cumulative exposure to vibration and the vascular and neurological symptoms of the hand-arm vibration syndrome (HAVS). In 2001, after a decade of exposure reduction and ageing of the workforce, a second study at the same site was initiated. METHODS: In 2001, 214 subjects were selected; they represented four current weekly vibration exposure time intervals--0 hr, >0 < 5 hr, > or =5 < 20 hr, > or =20 hr. The 1988 and 2000 cross-sectional populations were compared on the basis of exposure duration and current symptoms. RESULTS: In 2001, the study population was 9.6 years older than the 1988 group. Current weekly exposure hours were similar in the low and medium exposure groups 2001 and 1988, but exposure was reduced by an average of 9.7 hr per week in the highest exposure group (> or =20 hr) in 2001. Symptom severity was regressed polychotomously on estimated exposure (log cumulative hours); the OR was weaker in 2001 than in 1988 for sensorineural symptoms-1.44 [CI 1.04-1.98] versus 2.35 [CI 1.48-3.73]. This was also true for vascular symptoms-1.70 [CI 1.06-2.71] versus 3.99 [CI 2.27-7.01]. Vascular symptoms were more prevalent in the highest lifetime vibration exposure group in 1988 (68.7 vs. 43.2% in 2001); sensorineural symptoms were more prevalent in the least vibration exposed group in 2001 (52.6 vs. 20.7% in 1988). CONCLUSIONS: The prevalence of vascular symptoms associated with cumulative vibratory exposure was significantly greater in 1988, but neurological symptoms were more common at lower exposure levels in 2001. The presumption that reducing exposure duration alone is sufficient, in the absence of change in vibration magnitude, is not supported by the results of this study.     

A study of work-related musculoskeletal case reports to The Health and Occupation Reporting network (THOR) from 2002 to 2003

BACKGROUND: Occupational musculoskeletal disorders are frequently seen by occupational physicians and rheumatologists, and there are well-established UK-based schemes set-up for reporting these conditions. An apparent fall in case reporting for work-related musculoskeletal disorders in Great Britain to The Health and Occupation Reporting network (THOR) was observed from 2002 to 2003. AIMS: To investigate changes in case reporting for musculoskeletal disorders sent by occupational physicians to Occupational Physicians Reporting Activity (OPRA) and by rheumatologists to Musculoskeletal Occupational Surveillance Scheme (MOSS) between 2002 and 2003. METHODS: Musculoskeletal cases returned by more than 800 physicians from Great Britain reporting to OPRA and MOSS in 2002-2003 were analysed. Changes in reporting are described at individual physician and group levels in: numbers of participants, levels of response, and numbers of case reports by disease category and major occupational and industrial groups. RESULTS: In 2002-2003, musculoskeletal disease was the most frequently reported major disease category in OPRA. Between 2002 and 2003, the proportion of musculoskeletal case reporting fell by 37% in OPRA, and 7% in MOSS. This fall was seen in many disease categories, across a wide range of occupations and industries. In OPRA, the greatest fall in reporting (74%) was for the category Raynaud's/Hand-Arm Vibration Syndrome/Vibration White Finger. CONCLUSIONS: The fall in occupational musculoskeletal case reporting between 2002 and 2003 cannot be explained by internal factors within the reporting system. This observation highlights the need for systematic investigation of trends in case reporting for work-related ill-health.     

The analysis of sensitivity, specificity, positive predictive value and negative predictive value of cold provocation thermography in the objective diagnosis of the hand-arm vibration syndrome

The diagnosis of digital artery vasospasm in the hand-arm vibration syndrome (HAVS) is clinically based, and the need for an accurate objective test to support the diagnosis has been highlighted. This study aims to analyse the potential of cold provocation thermography (CPT) to fulfill this role. CPT was performed on two groups of subjects: 10 controls and 21 patients with Raynaud's phenomenon (RP) secondary to HAVS. After taking a pre-cooling image, patients donned latex gloves and immersed their hands in water at a temperature of 5 degrees C for 1 min. The patients removed their hands from the water and discarded the gloves, and further images were taken every 30 s for 10 min. On each image, the temperatures of the tip and base were analysed for each digit. The sensitivity, specificity, positive and negative predictive values for fingertip temperatures only, fingertip and fingerbase temperatures combined, and fingertip temperature, fingerbase temperature and temperature gradient combined were determined. Patients with RP secondary to HAVS demonstrated significantly lower finger tip and base temperatures and lower digital temperature gradients at all time intervals when compared with controls (P < 0.01, Student's t-test). CPT has good sensitivity, specificity, positive predictive value and negative predictive value; it strongly supports the clinical diagnosis of digital vasospasm.     

Delivery of health surveillance for hand-arm vibration in the West Midlands

BACKGROUND: Concerns about provider competence and quality of hand-arm vibrations (HAVs) health surveillance programmes were identified by Health & Safety Executive (HSE) inspectors. AIMS: To evaluate health surveillance programmes and compare them with published HSE guidance. To identify deficiencies and areas for improvement in the health surveillance programmes. METHODS: A proforma was developed for the study and used on a sample of 10 local occupational health providers. RESULTS: All 10 organizations were aware of current HSE guidance for health surveillance for HAVs but only a minority (30%) were following it. Occupational health provider training, written procedures and health surveillance delivery were all identified as areas requiring improvement. CONCLUSIONS: The majority of organizations were not following HSE guidance. Occupational health providers undertaking health surveillance for HAV require specific training.     

Cross sectional study of a workforce exposed to hand-arm vibration: with objective tests and the Stockholm workshop scales

OBJECTIVES—Medical surveillance of workforces exposed to vibration has been recommended with the Stockholm workshop scales. The aims of this study were (a) to evaluate how the results of the objective tests individually and jointly associated with the final Stockholm workshop staging, (b) how this staging related to the history of exposure to vibration, and (c) how different trades were affected by the hazards from vibrating tools.
METHODS—All workers exposed to vibration in a heavy engineering company were examined with a questionnaire and a battery of tests. An assessment of staging by the Stockholm workshop scales was made. Estimates of the daily exposure and lifetime dosage of vibration of the various trades were reached.
RESULTS—The average years of tool use was 23.3 years (range 3-47 years) and the mean lifetime exposure was 11 022 (range 1012-46 125) hours. The individual neurological tests were all strongly associated with the Stockholm neurological staging but the cold provocation test was not associated with the Stockholm vascular staging. Neurological staging was significantly associated with age, years of tool use, and total hours of exposure to vibration, but not with trade or smoking. Vascular staging was significantly associated with age, years of tool use, total hours of exposure to vibration, and trade, but not with smoking. The mean neurological latent period was 19.7 (range 2-40) years and for the vascular component 19.1 (range 2-40) years. These means varied significantly by trade. The overall prevalence of neurological findings of 62% was greater than the overall prevalence of vascular findings, which was 33%.
CONCLUSIONS—(1) The neurological objective tests were found to be of use in neurological staging. The cold provocation test was not associated with the vascular staging and therefore was of little value. (2) Years of tool use was the exposure variable most significantly associated with evidence of damage to neurological component while years of tool use and trade were the variables most associated with vascular damage. (3) The prevalence of neurological symptoms (62%) was greater than the prevalence of vascular symptoms (33%). (4) Dressers and welders have shorter latent periods than platers and fitters.


Keywords: hand-arm vibration syndrome; neurological objective tests     

Hand-arm vibration syndrome with concomitant arterial thrombosis in the hands

BACKGROUND: Hand-arm vibration syndrome (HAVS) refers to the vascular, neurological and musculoskeletal effects that may occur in workers with prolonged exposure to vibrating tools. Hypothenar hammer syndrome (HHS) is a lesion of the ulnar artery at the level of the hamate bone secondary to single or repeated episodes of trauma to the hypothenar eminence. The literature suggests that digital arterial thrombosis and HHS may be associated with the use of vibrating tools. AIM: This study will familiarize investigators with the range of vascular abnormalities seen in workers using vibrating tools, and highlight the importance of screening for arterial thrombosis in the hand when assessing hand-arm vibration-exposed patients. METHODS: In the patients referred to our clinic for HAVS assessment, three were identified during the period 2001 to 2004 who had vascular occlusions in the hands in addition to HAVS. In addition to standardized HAVS vascular investigations, all three patients had arteriograms based on a significantly positive Allen's test. RESULTS: All three cases had documented HAVS based on vascular testing. Arteriograms revealed a spectrum of severity of arterial thromboses from severe HHS, to occlusion limited to the digital arteries. CONCLUSION: Our study reports three cases of HAVS with concomitant HHS and/or digital artery thrombosis. These findings support previous reports of an association between HAVS and vascular thrombosis in the hands. Screening for arterial occlusive problems in the hands should be included in the HAVS work up.     

Review of objective tests for the hand--arm vibration syndrome

The Health and Safety Executive has recommended health surveillancefor all workers in jobs identified as giving rise to significantrisk of the hand-arm vibration syndrome. Objective tests arenot routinely recommended for workplace surveillance but mayhave a role in the assessment of accurate staging or if decisionson an individual's continuing exposure is in question. Thispaper covers the use of multiple objective tests, the collectionof routine data, a proposed scoring system for the sensorineuralcomponent and discusses the role of cold provocation testingin the diagnosis of the vascular component.     

Upper limb disability in HAVS cases--how does it relate to the neurosensory or vascular elements of HAVS?

AIMS: Hand-arm vibration syndrome (HAVS) consists of vascular, neurosensory and musculoskeletal components, characterized by symptoms that include Raynaud's phenomenon, tingling and numbness in the hands. However, there has been little published data on the effects of HAVS on the capability to carry out normal daily tasks. We have investigated the application of the widely-used disability, arm, shoulder and hand (DASH) disability questionnaire that reflects functionality problems in the upper extremities, as well as symptoms, in a HAVS cohort. METHODS: The cohort consisted of 118 males who, as a part of their health surveillance, had been referred for further assessment and Stockholm workshop staging. This process involved medical interview, physical examination and quantitative tests covering neurosensory function, manual dexterity and handgrip strength. RESULTS: The relationship between DASH outcome metric and a combination of quantitative tests reflecting a range of abnormalities found in HAVS, supports the validity of this questionnaire in HAVS studies. The data suggest that HAVS cases have a greater level of upper extremity disability compared with a general population. The study confirms that disability in HAVS is very largely related to sensorineural Stockholm workshop staging, rather than vascular staging. Any influence of vibration-induced Raynaud's phenomenon on upper extremity disability is related to the frequency of blanching attacks rather than their extent across the digits. CONCLUSION: This study strengthens the importance of identifying and preventing the exacerbation of the neurosenory component of HAVS, that unlike the blanching attacks of the vascular component does not have such an obvious pathognomic signal.     

A comparison between two methods of aesthesiometric assessment in patients with hand-arm vibration syndrome.

Hand-arm vibration syndrome (HAVS) is caused by prolonged exposure to vibration. The diagnosis and assessment of disease severity are subjective at present. The aim of this study was to determine sensorineural dysfunction in patients with HAVS using two methods of aesthesiometric assessment. We recruited three groups of age-matched subjects: 20 subjects diagnosed as having HAVS, 15 manual workers and 15 sedentary workers. We measured both two-point discrimination and depth sense perception using an aesthesiometer. We found that the two-point discrimination wheel was more accurate than the depth sense perception wheel at detecting levels of sensorineural dysfunction in subjects with HAVS. The increased sensitivity of the two-point disc would suggest that it should be used in preference to the depth sense disc for the assessment of sensorineural dysfunction in patients with HAVS.     

How a sample of businesses in the West Midlands (UK) are currently managing vibration exposure

This paper discusses the results of a local initiative in the West Midlands (UK) which looked at how businesses in engineering, utilities and foundry trades managed the risks from hand-arm vibration. Inadequacies of health surveillance programmes and the need for enforcement action are outlined.     

Musculoskeletal disorders in farmers and farm workers

Farming is a physically arduous occupation and this places farm workers at potential risk of musculoskeletal disorders such as osteoarthritis (OA) of the hip and knee, low back pain (LBP), neck and upper limb complaints, and hand-arm vibration syndrome (HAVS). This review considers the epidemiological evidence concerning such risks. The strongest evidence relates to OA of the hip, for which the public health impact is likely to be considerable. There is also weaker, but suggestive evidence that farmers more often have knee OA and LBP than workers in occupations with fewer physical demands. Tractor drivers, in particular, seem to have more LBP. Relatively little information exists on the risks of soft tissue rheumatism in the limbs and neck. For some outcomes, the link with occupational risk factors (such as heavy loading of joints and whole-body vibration) is sufficient to suggest the course that future prevention should take, but for several outcomes more research is first needed.     

Ascertaining the risk of chronic obstructive pulmonary disease in relation to occupation using a case-control design

BACKGROUND: Recent community surveys have reported a risk of chronic obstructive pulmonary disease (COPD) in occupations involving exposure to organic dust and gas/vapour. Aims Our aim was to confirm these results using a case-control design on 131 COPD cases (FEV(1) < 80% of predicted value, minimally reversible with bronchodilators) and 298 controls, selected from registers for patients admitted to our Institute of Occupational Medicine. METHODS: Surrogates of past exposure were occupation, exposure assigned by a job-exposure matrix, and years spent in a given occupation. The odds ratio (OR) and 95% confidence interval (CI) for COPD were calculated using logistic regression models with office workers as the reference. RESULTS: Age-smoking-adjusted ORs (and CIs) were: 15.1 (3.2-71.6) in farmers; 7.2 (1.3-41.1) in cotton workers; 6.4 (1.6-25.5) in welders; 4.7 (1.3-16.4) in painters; 12.1 (1.3-108) in foundry workers; 6.50 (1.14-37.0) in refractory brick workers; and 3.1 (1.0-9.5) in construction workers. In farmers, cotton workers, welders and painters, the adjusted ORs significantly increased (by 6-9%) for each extra year of work, while in other occupations any such increase was of borderline significance. Adjusted ORs were 3.80 (1.21-12.0), 5.83 (1.82-18.6) and 8.86 (2.29-34.3) in workers exposed to high levels of mineral dust, gas/vapour/fume and biological dust, respectively. Consistent risk estimates were obtained for farmers, textile workers, painters and welders. CONCLUSIONS: Our findings confirm previous epidemiological evidence and are supported by recent observations that cigarette smoke, cotton and organic farm dust contain the same powerful pro-inflammatory agents, and that organic dust and irritant gas induce bronchitis by triggering the same effector molecules as cigarette smoke.     

Validity of various function tests performed in Japan as a screening test for vibration syndrome

Summary In Japan, various function tests on the upper extremities are widely performed for the early diagnosis of vibration syndrome. The validity of these function tests was investigated by discriminant function analysis. The correct classification rate of the 120 workers exposed to vibration and the 40 control workers was 83.1%, when including the exposure-to-cold test. Therefore, the function tests were confirmed to be of diagnostic significance as a screening test for vibration syndrome. However, the rate is not sufficient to make a diagnosis only with the function tests. When not including the exposure-to-cold test, the rate was reduced by 10% because insidious functional disorders were missed in the early stage. For the early diagnosis of vibration syndrome, the exposure-to-cold test should be included in the function tests. Furthermore, to enhance the validity of the diagnosis, the results of the function tests should be evaluated together with subjective symptoms and the findings on bones and joints, the central nervous system and the endocrine system.     

Comparison of two methodologies for detection of Giardia spp. cysts and Cryptosporidium spp. oocysts in activated sludge samples from a sewage treatment plant in the city of Campinas, Sao Paulo State, Brazil

Giardia spp. and Cryptosporidium spp. are recognized worldwide as highly infectious protozoan parasites that can cause severe gastrointestinal disease in humans and animals. The detection of these pathogens in activated sludge samples becomes interesting since there is an increasing trend for the use of sewage sludge (biosolids) in agriculture. A total of 22 samples were collected and evaluated by means of Centrifugal – Concentration, followed or not followed by a purification process (ether clarification and sucrose flotation). Student t tests for comparison of the two procedures indicated a higher recovery rate of Giardia cysts with Centrifugal – Concentration; with regard to Cryptosporidium oocysts, no significant differences were found between the two methods, as only two samples were positive. The Centrifugal – Concentration procedure was shown to be the simplest and cheapest to perform, as emphasized by the efficiency recovery results.