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.     

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.     

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.     

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 screening questionnaire for HAVS?

AIM: To define the diagnostic power of simple questions most applicable for a hand-arm vibration syndrome (HAVS) assessment screening questionnaire. METHOD: Using a binary logistic regression we analysed 365 physician led HAVS health surveillance assessments to identify which questions could form the basis of a screening questionnaire. RESULTS: Four sensorineural related questions regarding tingling and numbness in response to the cold and after using vibrating tools, and two vascular-related questions focusing on the patient's fingers going white on exposure to cold and numbness during an attack of whiteness were identified. CONCLUSIONS: Questions of high sensitivity for screening subjects for the vascular and neurosensory components of HAVS were identified, which can be used to identify those requiring further clinical investigation and functional testing.     

Acute respiratory symptoms among sisal workers in Tanzania

Background Few studies have focused on respiratory health effectsamong sisal workers. Aim To report on the prevalence of acute respiratory symptomsamong sisal processors. Methods We interviewed 163 dust-exposed brushing and decorticationworkers and 31 low-exposed security workers from six sisal estatesin Tanzania using a modified symptom score questionnaire todetermine the prevalence of acute respiratory symptoms duringwork. Groups were compared using chi-square tests, Fisher'sexact tests, t-tests and logistic regression, adjusting forconfounding factors. Results After the first working day of the week, 73% of thebrushing workers reported dry cough, 66% sneezing, 65% productivecough, 63% running nose and 34% stuffy nose. Brushing workershad a significantly higher prevalence of these symptoms thandecortication workers. Brushing and decortication workers hadsignificantly more dry cough and sneezing than the control groupof security workers, when adjusting for age, smoking, past respiratorydiseases and residence. Conclusion Processors of sisal fibre have a high prevalenceof acute respiratory symptoms. More detailed studies on workand health in sisal estates are needed, including exposure studies.     

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.     

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.     

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.     

Accidental blood and body fluid exposure among doctors

Aim To study the epidemiology and time trends of blood and bodyfluids (BBF) exposures among hospital doctors. Methods A 3-year study was carried out using data from the ExposurePrevention Information Network of four teaching hospitals inthe UK. Results One hundred and seventy-five cases of BBF exposuresin doctors were reported over the 3-year study period. Eighty-one(46%) occurred in senior doctors and 94 (54%) in junior doctors.Junior doctors had a higher rate of BBF exposures compared tosenior doctors: 13 versus 4 incidents per 100 person-years,respectively (relative risk 3, 95% confidence interval 2–4).The most frequent setting for BBF exposures among senior doctorswas the operating theatre/recovery (59%). Among junior doctors,it was the patient room (48%). The commonest original reasonfor use of sharps by junior doctors was the taking of bloodsamples (42%). Among senior doctors, it was suturing (41%). Conclusion While ongoing training efforts need to be directedtowards both junior and senior doctors, our data suggest thatjunior doctors are at higher risk of BBF exposures and may needparticular attention in prevention strategies. An improvementin the safety culture in teaching hospitals can be expectedto reduce the number of BBF exposures.     

Doctors, their mental health and capacity for work

Background Information about doctors’ mental ill-healthis limited. This study looks at doctors’ careers followingmental illness and the strategies that helped them return towork. Aim To examine the effect of mental ill-health on doctors’careers. Methods Questionnaire survey of members of the Doctors SupportNetwork (DSN). The DSN is a peer support group for doctors whohave experienced, or are experiencing, mental ill-health. Results One hundred and sixteen doctors (35% response rate)returned completed questionnaires (n = 116, 63% female, 37%male). Prior to their ill-health, 80% worked full time, 15%part-time, 2% were not working and 3% were medical students.Following illness, 33% worked full time (P < 0.05), 36% part-time(P < 0.05) and 29% were not working (P < 0.01). Flexibleworking practices were the most helpful reported strategy forenabling a doctor to return to work. Conclusions Following mental ill-health, a doctor’s capacityto work full time is reduced. Most doctors return to full-timeor part-time work. With improved support, more doctors may beable to return to work.     

Which agents cause reactive airways dysfunction syndrome (RADS)? A systematic review

Aim To identify those agents reported as being associated withreactive airways dysfunction syndrome (RADS). Methods A systematic review was undertaken. Abstracts were screenedand those selected reviewed against pre-determined diagnosticcriteria for RADS. Results Significant information gaps were identified for allmeasures of interest. In some articles, even the causative agentwas not reported. The most commonly reported agents were chlorine(nine subjects), toluene di-isocyanate (TDI) (n = 6) and oxidesof nitrogen (n = 5). Most exposures occurred in the workplace(n = 51) and affected men (60%). Dyspnoea (71%) and cough (65%)were the commonest symptoms. Median symptom duration was 13months (interquartile range = 6.5–43.5) for RADS. Conclusions Although the most commonly reported agent associatedwith RADS was chlorine, the main finding of a general lack ofadequate information on exposure, investigation and outcomesuggests that to better explore RADS a more structured approachto gathering information is required. A minimum data set forreporting RADS cases is proposed.     

Use of sensorineural tests in a large volume of medico-legal compensation claims for HAVS

BACKGROUND: The Department of Trade and Industry set up a contract to examine miners and ex-miners claiming compensation for hand-arm vibration syndrome (HAVS). They had been exposed to hand-transmitted vibration. Over 100,000 have now been examined using sensorineural tests as part of that process. AIMS: The purpose of this paper was to examine the internal consistency of the vibrotactile threshold test (VTT) and the thermal aesthesiometry test (TA). METHODS: In 18 centres across the UK, nurses were trained to perform the measurement of VTT and TA in a controlled standardized manner. These tests were to aid the staging of the neurological component of the Stockholm Workshop Scales. The staging of this component was modified by dividing stage 2SN into 2SN (early) and 2SN (late). The test results and an automatic neurological staging were presented to the examining doctor following the clinical examination. The results of these sensorineural tests were held on a central database. The results and analysis of the first 57,000 tests are reported. RESULTS: The correlations within the VTT and TA scores were consistent with reliable measures. However, these correlations were not of such strength as to allow reliance on the results of a single test when making an assessment of the severity of neurological damage. CONCLUSIONS: Different end organs and nerve fibres should be tested when making an assessment of damage in the sensorineural component of HAVS. The correlations demonstrated for the VTT and TA suggest that they are of value in assessing these claimants and would be for other vibration exposed workers.     

Attitudes to job turnover among Finnish anaesthetists

Background Structural changes have led to higher workload andmore frequent conflicts among hospital staff, which in turnhas been shown to be associated with increased employee turnover. Aims To study the willingness of anaesthetists to change theiremployment and factors associated with it. Work-related, individualand family-related factors were investigated as potential influenceson such willingness. Method A postal questionnaire was sent to all working Finnishanaesthetists (N = 550). Results The response rate was 60%; 175 (53% of responders) weremen. Of the respondents, 31% were willing to consider changingto another physician's job and 43% to a profession other thanmedicine. The most important correlates for these views wereconflicts with superiors (odds ratio 6.1; 95% confidence interval2.1–17.7) and co-workers (4.2; 1.4–12.2), low jobcontrol (2.6; 1.4–4.9), a sense of organizational injustice(2.4; 1.3–4.6), stress (6.5; 2.6–16.3) and job dissatisfaction(4.6; 2.4–8.8). Conclusions The establishment of respect, trust and genuinedialogue between co-workers and superiors is needed to minimizethe risk of loss of members of this occupational group.     

Exposures to blood and body fluids in Brazilian primary health care

Background Primary health care workers (HCWs) represent a growingoccupational group worldwide. They are at risk of infectionwith blood-borne pathogens because of occupational exposuresto blood and body fluids (BBF). Aim To investigate BBF exposure and its associated factors amongprimary HCWs. Methods Cross-sectional study among workers from municipal primaryhealth care centres in Florianópolis, Southern Brazil.Workers who belonged to occupational categories that involvedBBF exposures during the preceding 12 months were interviewedand included in the data analysis. Results A total of 1077 workers participated. The mean incidencerate of occupational BBF exposures was 11.9 per 100 full-timeequivalent worker-years (95% confidence interval: 8.4–15.3).The cumulative prevalence was 7% during the 12 months precedingthe interview. University-level education, employment as a nurseassistant, dental assistant or dentist, higher workload score,inadequate working conditions, having sustained a previous occupationalaccident and current smoking were associated with BBF exposures(P 0.05). Conclusions Primary Health Care Centres are working environmentsin which workers are at risk of BBF exposures. Exposure surveillancesystems should be created to monitor their occurrence and toguide the implementation of preventive strategies.     

An evaluation of stress education in the Royal Navy

Background Psychoeducational programmes aim to reduce the morbidityassociated with exposure to stressful events. Although theyare widely used, there are conflicting views as to how or whythey might be effective. Aim To examine exposure to ‘stress’ education withinthe Royal Navy (RN) and ascertain any links between stress educationand mental health status. Methods In all, 1559 RN personnel were surveyed using a studyquestionnaire which asked about exposure to and quality of anystress education provided during service. Participants alsocompleted two measures of psychological health, the GeneralHealth Questionnaire (GHQ)-12 item and the Post-Traumatic StressDisorder Checklist. Odds ratios (ORs) were calculated and 95%confidence intervals were computed using multivariable logisticregression adjusting for socio-demographic variables. Results The response rate was 70%; 47% of the sample reportedhaving received a stress brief during service. Those who reportedhaving received a brief had better general mental health (measuredby the GHQ) than those who had not [adjusted, OR = 0.76 (0.59–0.98)].When brief quality was taken into account, only those who receiveda brief and considered it ‘useful’ were significantlyless distressed [adjusted, OR = 0.65 (0.49–0.86)]. Poor-qualitybriefs were no better than having had no brief at all [adjusted,OR = 1.04 (0.74–1.47)]. Conclusions Our data indicate that only educational stress briefswhich are relevant for the target audience may be beneficial.Simply providing stress briefings, without thought to theirquality, may constitute a waste of resources.     

Determinants of work ability and its predictive value for disability

Background Maintaining the ability of workers to cope with physicaland psychosocial demands at work becomes increasingly importantin prolonging working life. Aims To analyse the effects of work-related factors and individualcharacteristics on work ability and to determine the predictivevalue of work ability on receiving a work-related disabilitypension. Methods A longitudinal study was conducted among 850 constructionworkers aged 40 years and older, with average follow-up periodof 23 months. Disability was defined as receiving a disabilitypension, granted to workers unable to continue working in theirregular job. Work ability was assessed using the work abilityindex (WAI). Associations between work-related factors and individualcharacteristics with work ability at baseline were evaluatedusing linear regression analysis, and Cox regression analysiswas used to evaluate the predictive value of work ability fordisability. Results Work-related factors were associated with a lower workability at baseline, but had little prognostic value for disabilityduring follow-up. The hazard ratios for disability among workerswith a moderate and poor work ability at baseline were 8 and32, respectively. All separate scales in the WAI had predictivepower for future disability with the highest influence of currentwork ability in relation to job demands and lowest influenceof diseases diagnosed by a physician. Conclusion A moderate or poor work ability was highly predictivefor receiving a disability pension. Preventive measures shouldfacilitate a good balance between work performance and healthin order to prevent quitting labour participation.     

Health care workers' exposure to blood-borne pathogens in Lebanon

Background Accidental exposure to blood-borne pathogens (BBPs)is a risk for health care workers (HCWs). Aim To study the pattern of occupational exposure to blood andbody fluids (BBFs) at a tertiary care hospital. Methods This study reports a 17-year experience (1985–2001)of ongoing surveillance of HCW exposure to BBFs at a 420-bedacademic tertiary care hospital. Results A total of 1590 BBF exposure-related accidents werereported to the Infection Control Office. The trend showed adecrease in these exposures over the years with an average ±standard error of 96 ± 8.6 incidents per year. In thelast 6 years, the average rate of BBF exposures was 0.57 per100 admissions per year (average of needlestick injuries alonewas 0.46 per 100 admissions). For 2001, the rates of exposurewere found to be 13% for house officers, 9% for medical student,8% for attending physicians, 5% for nurses, 4% for housekeeping,4% for technicians and 2% for auxiliary services employees.The reason for the incident, when stated, was attributed toa procedural intervention (29%), improper disposal of sharps(18%), to recapping (11%) and to other causes (5%). Conclusions The current study in Lebanon showed that exposureof HCWs to BBPs remains a problem. This can be projected toother hospitals in the country and raises the need to implementinfection control standards more efficiently. Similar studiesshould be done prospectively on a yearly basis to study ratesand identify high-risk groups.     

Overtime work and stress response in a group of Japanese workers

Background Working long overtime hours is considered a causeof mental health problems among workers but such a relationshiphas yet to be empirically confirmed. Aim To clarify the influence of overtime work on response tostress and to assess the role of other stress-related factorson this relationship. Methods The study was conducted among 24 685 employees of acompany in Japan. Stress response, job stressors and socialsupports were assessed by the Brief Job Stress Questionnaire.Participants were divided into five categories of overtime (0–19,20–39, 40–59, 60 h of overtime per month and exemptedemployees). Results The nonadjusted odds ratios for stress response for40–59 and 60 overtime hours per month in reference to0–19 overtime hours were 1.11 [95% confidence interval(CI) 1.03–1.19] and 1.62 (95% CI 1.50–1.76), respectively.After adjustment for self-assessed amount of work, mental workloadand sleeping time, the association between overtime work andstress response disappeared. Conclusions This large cross-sectional study shows that overtimework appears to influence stress response indirectly throughother stress factors such as self-assessed amount of work, mentalworkload and sleeping time.