Preliminary Study on the Assessment of Peripheral Vascular Response to Cold Provocation in Workers Exposed to Hand-Arm Vibration Using Laser Doppler Perfusion Imager

Abstract

Measurements of changes in finger skin blood flow with laser Doppler perfusion imaging (LDPI) in response to cold provocation test (10°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 accurate information that may help detect the peripheral circulatory impairment in the fingers of vibrationexposed workers.

Advanced tools for in vivo skin analysis

“…Laser Doppler scanners make it possible to obtain images of blood microcirculation in the skin (laser Doppler imaging – LDI). The laser Doppler perfusion imager (LDPI) is another type of scanning device, which can be employed to evaluate changes in skin microcirculation, e.g., tuberculin reactions 23,24 …”

“…Research performed by Miyai et al. 24 showed that LDPI can be a valuable tool not only for visualization but also for quantification of the changes caused by cold water immersion in blood flow in the skin of the fingers.…”

Review of Different Quantification Methods for the Diagnosis of Digital Vascular Abnormalities in Hand‐arm Vibration Syndrome

“…This variability can be diminished if measurement of finger blood flow is incorporated with a local hot or cold provocation test. Moreover, skin perfusion is frequently characterized by large spatial variation with substantial differences in perfusion even at adjacent areas 34) . Therefore, investigation of blood flow over a small area may not represent the surrounding blood flow.…”

“…Visualization of blood perfusion over a larger hand skin area can help in the detection of impaired digital vascular regulation in VWF patients 34) . In their study, Miyai et al suggested that the LDPI is an important technique enabling quantification of finger skin blood flow response to cold water immersion and has the potential of providing detailed and accurate information to aid in the detection of peripheral circulatory impairment in the fingers of vibration-exposed workers 34) . Human hand skin microcirculation is accomplished through the superficial capillary (nutritive) network and the deeper subpapillary (thermoregulatory) network 35) .…”

Laser Doppler Imaging of Skin Blood Flow for Assessing Peripheral Vascular Impairment in Hand-Arm Vibration Syndrome

“…By the introduction of the imaging concept, the spatial heterogeneity of the cutaneous tissue perfusion can be investigated, while, at the same time, averaging the blood perfusion over an area of a specific extension increases the reproducibility 13,14) . The LDPI technique may therefore have the benefit of detecting the vasospastic abnormalities of the digital artery in HAVS patients 15,16) , which generally appear with an inhomogeneous reaction to cold [3][4][5] . In the present study, measurements of the changes in finger skin blood flow in response to a cold water immersion test were performed in patients suffering from HAVS and unexposed healthy controls by using LDPI in order to examine whether the technique can provide valuable information that may support the diagnosis of the peripheral vascular impairment of workers occupationally exposed to hand-arm vibration.…”