The General Characteristics and Results of the Cold Provocation Test in the Risk Group of HAVS / 대한산업의학회지

ABSTRACT

OBJECTIVES: The cold provocation test for diagnosing the vascular component in hand-arm vibration syndrome (HAVS) is likely to be accepted as an objective test, and a few studies have been performed. However, controversy has continued regarding the diagnostic performance of this method. Although objective methods such as plethysmography and laser doppler flowmetry have been studied, they have not received as much attention as other diagnostic methods. Therefore, our study aim was to spread the awareness of HAVS by reporting the results of the cold provocation test in a hand-transmitted vibration exposure group. METHODS: The study subjects were 549 workers who had been exposed to hand-transmitted vibrations and reported symptoms in their hands. While the subject immersed both their hands in 10degrees C water for 10 minutes, the skin temperature of 10 fingers was recorded from pre-immersion time to 20 minute postimmersion including 10 minutes immersion time. The recovery rates were calculated from the recorded skin temperatures. The 'decreased recovery rate' criteria were less than 30% at 5 minutes post-immersion and 60% at 10 minute post-immersion. RESULTS: Of the subjects, 69.1% and 30.9% had more severe symptoms in the right and left hands, respectively. The mean finger skin temperature of the right hand after cold-water immersion for 10 minutes was approximately 10degrees C, which increased gradually with time, but they did not reach the baseline temperature at 20 minutes post-immersion. The deviations of the skin temperature in the subjects were higher in the recovery phase than in the baseline and cold immersion phase. The 3rd finger of both hands showed the lowest 5-minute recovery rate among the fingers examined, and the left 4th finger and right 3rd finger showed the lowest 10-minute recovery rate. Of the subjects, 37.6% and 10.4% of subjects showed a lower recovery rate at 5 and 10 minutes in at least one finger, respectively, while 10.2% showed a lower recovery rate at both 5 and 10 minutes simultaneously in at least one finger. CONCLUSIONS: The larger deviations in the recovery phase than in the other phases indicated that interindividual differences are more prominent in the recovery phase. There might be no benefit in observing the finger skin temperature for an additional 10 minutes after 10 minutes post-immersion. Overall, approximately 10% of the subjects in the HAVS risk group had HAVS.