Association between vasoconstriction during following exposure hand-transmitted vibration | ANMA – Associazione Nazionale del Medico Competente e d'Azienda

Vol. 87, Iss. 1, January 2014

Association between vasoconstriction during and following exposure to hand-transmitted vibration

Ying Ye, Marcella Mauro, Massimo Bovenzi, Michael J. Griffin

Riassunto

Objectives This study investigated whether reductions in finger blood flow (FBF) during and after vibration are similarly dependent on the magnitude and duration of the vibration.

Methods FBF on the left and right hand was measured every minute during, and for 1 h following, exposure of the right hand to one of three magnitudes of 125-Hz sinusoidal vibration (0, 22, or 88 ms−2 rms) for one of two durations (7.5 or 15 min). Each of five experimental sessions was comprised of five periods: (i) no force and no vibration (5 min), (ii) 2-N force and no vibration (5 min), (iii) 2-N force and vibration (7.5 or 15 min), (iv) 2-N force and no vibration (5 min), and (v) no force and no vibration (60 min).

Results Vibration reduced FBF in the exposed and unexposed hands, both during and after vibration. With increased magnitude of vibration, there was increased vasoconstriction in all fingers during and after exposure, and longer recovery times after vibration exposure. With increased duration of vibration, there were no changes in vascular responses during exposure but increased vasoconstriction after exposure and prolonged recovery times. With the greater vibration magnitude, the reduction in FBF during exposure was correlated with the time taken to recover after exposure.

Conclusions Subjects with greater reduction in blood flow during vibration exposure also have stronger and longer vasoconstriction during subsequent recovery. The correlation between vascular changes during and after vibration exposure suggests similar mechanisms control FBF during and after vibration exposure.

Commento

Vari studi sperimentali hanno dimostrato che l'esposizione professionale a vibrazioni da parte degli arti superiori è in grado di generare una progressiva riduzione del flusso ematico a livello delle estremità di questi ultimi. Il grado di vasocostrizione risulta essere differente a seconda della frequenza e dell’ampiezza delle vibrazioni e permane, per un periodo variabile, anche dopo la cessazione dell’esposizione. Di particolare interesse, sul tema, sono alcune ricerche di Bovenzi e collaboratori pubblicate tra il 2000 ed il 2006 nelle quali l’esposizione a vibrazioni, da parte di una sola mano, è stata in grado di provocare una vasocostrizione sia delle dita della mano esposta che di quella non esposta.

Il presente studio approfondisce le conoscenze della letteratura sul tema ed è stato progettato, da un gruppo di ricerca dell’università di Southampton, con lo scopo comprendere i differenti meccanismi anatomofisiologici coinvolti nelle vasocostrizioni che si verificano durante e dopo l'esposizione a vibrazioni trasmesse agli arti superiori.

Keywords

Dampness, disability, Mold, occupational asthma, Work ability

Rassegna bibliografica