Vascular Component Of Hand-arm Vibration Syndrome Research Articles

Cryoglobulins and cold agglutinins for hand arm vibration syndrome.

Hand arm vibration syndrome (HAVS) is a condition caused by hand transmitted vibration from the use of hand-held vibrating tools or workpieces. The disease affects the vascular, neurological and musculoskeletal systems. The vascular component of HAVS is a form of secondary Raynaud's phenomenon. Other causes of disease must be excluded before attributing the cause to hand transmitted vibration. To evaluate the prevalence, and utility of testing for, cryoglobulins and cold agglutinins in patients with HAVS symptoms. A retrospective cohort study of 1183 patients referred for HAVS clinical assessment at St. Michael's Hospital, Toronto, Canada, between 2014 and 2020. The standard operating procedure at the clinic includes a detailed clinical and exposure history, physical examination, objective investigations and blood tests. Data were retrieved from patient chart review and laboratory investigation results for all cases with cryoglobulin and cold agglutinin testing. A total of 1183 patients had a serum cryoglobulin measurement. Eleven patients (1%) were positive. Seven positive results were 'low titre' (1% positive) and the other four results were 2%, 6%, 9% and 18%. The patient with a 9% positive cryoglobulin titre had previously diagnosed Sjögren's syndrome. There were no positive cold agglutinin tests in the 795 patients tested. Routine testing for cryoglobulins and cold agglutinins in patients with HAVS symptoms is not recommended because test positivity rates are negligible. Testing may be considered if the clinical history or routine blood investigations suggest evidence of underlying cryoglobulinaemia or cold agglutinin disease.

Infrared thermography in the hands and feet of hand-arm vibration syndrome (HAVS) cases and controls

This study evaluated IR thermography during 15 min of re-warming after cold water immersion in accordance with ISO guidelines (12 °C for 5 min) in cases with the vascular component of HAVS and controls. The purposes of the study were: (1) To evaluate the performance of IR thermography as a diagnostic test for the vascular effects of HAVS in the fingers, (2) To determine if there were any temperature differences in the toes between cases and controls and, if so, to evaluate the IR thermography as a diagnostic test for toe vascular effects in HAVS. A total of 39 HAVS cases and 46 controls were included in the study. In the fingers, an ROC analysis indicated that the highest areas under the curve (AUC) were obtained at 7 min of re-warming for the fingertips, middle phalanges and proximal phalanges. However, at these locations and time period of re-warming the sensitivities and specificities were not sufficiently high. For example a sensitivity of 66.7% was associated with specificities of 60.9%–67.4%. In the toe analysis 33 (84.6%) cases but only 3 controls (6.5%) reported increased cold intolerance in the feet and this difference was statistically significant (p < 0.001). These 33 cases were then compared to the 46 controls. In the ROC analysis for the toes, the AUC's were lower than those for the fingers and the estimated sensitivities and specificities were worse for the toes than for the fingers. However some statistically significant colder temperatures were found in cases in comparison to controls towards the end of the re-warming period. IR thermography after the ISO recommended cold water stimulation conditions did not perform well as a diagnostic test in the hands or feet. The statistically significant colder temperatures in the toes towards the end of re-warming are relevant to our understanding of foot vascular effects associated with vibration. In industry there is recent interest in determining the effects of foot transmitted vibration (FTV). Many workers have mixed HAV and FTV and it is important to account for feet effects secondary to HAVS in the hands when evaluating the effects of FTV.

Factors affecting finger and hand pain in workers with HAVS.

Pain and its management are important aspects of hand-arm vibration syndrome (HAVS). To determine the factors associated with finger and hand pain in workers with HAVS and, specifically, to assess the impact of several neurological variables as well as the vascular component of HAVS, grip strength and age. We assessed men with HAVS at a hospital occupational medicine clinic over 2 years. Subjects scored finger and hand pain separately using the Borg Scale (0-10). The possible predictors we evaluated included the Stockholm Neurological Scale (SNS) and Stockholm Vascular Scale (SVS) stages, current perception threshold (CPT), carpal tunnel syndrome (CTS), ulnar neuropathy, grip strength and age. We carried out nerve conduction testing to confirm the presence of CTS and ulnar neuropathy and measured CPT in the fingers at 2000 Hz, 250 Hz and 5 Hz corresponding to A-beta (large myelinated), A-delta (small myelinated) and C (unmyelinated) fibres, respectively. We calculated Spearman rank correlations to examine the relation between finger and hand pain and possible predictor variables. Among the 134 subjects, the median (25th-75th percentile) pain scores were 6 (4-8) for the fingers and 5 (1-7) for the hands. We found statistically significant correlations with finger pain for the SVS stage (r = 0.239; P < 0.01) and CTS (r = 0.184; P < 0.05). The only statistically significant correlation identified for hand pain was a negative correlation with grip strength (r = -0.185; P < 0.05). Management of finger and hand pain in HAVS should focus on the correlates we have identified.