Finger cold-induced vasodilation during mild hypothermia, hyperthermia and at thermoneutrality.
BACKGROUND
Exposure of the fingers to severe cold leads to cold-induced vasodilation (CIVD). The influence of ambient temperature on the CIVD-response is well understood and documented, but the response of CIVD to hyperthermia and mild hypothermia has rarely been investigated.


METHODS
To investigate the influence of body thermal status on the CIVD response, eight subjects immersed their right hand in 5 degrees C water for 40 min during mild hypothermia (C), thermoneutrality (N) and hyperthermia (W). The mean skin temperature of the body (Tsk), the esophageal temperature (Tes), the temperature of the volar side of the distal phalanx of each immersed finger (Tfi) and the skin perfusion of the immersed middle finger (Qsk) were continuously measured.


RESULTS
During the W condition the body temperatures were higher (Tes: 38.0+/-0.1 degrees C; Tsk: 37.9+/-0.7 degrees C) than during N (Tes: 36.8+/-0.2 degrees C; Tsk: 31.8+/-0.7 degrees C) and during C (Tes: 36.1+/-0.8 degrees C; Tsk: 21.2+/-1.9 degrees C). Tfi and Qsk were higher during the W condition (Tfi: 16.5+/-2.3 degrees C; Qsk: 133+/-53 perfusion units (PU)) than during N (Tfi: 8.1+/-1.7 degrees C; Qsk: 57+/-39 PU) and during C (Tfi: 6.8+/-1.2 degrees C; Qsk: 22+/-14 PU). The onset time of CIVD was significantly prolonged in condition C (13.0+/-3.8 min) as compared with N (7.2+/-2.2 min).


CONCLUSIONS
It was concluded that the CIVD response is significantly affected by body core and skin temperatures.
Daanen
H A
HA
Department of Work Environment, TNO Human Factors Research Institute, Soesterberg, The Netherlands. daanen@tm.tno.nl
Ducharme
M B
MB
D000328:Adult; D000704:Analysis of Variance; D001831:Body Temperature / Q000502:physiology*; D003080:Cold Temperature / Q000009:adverse effects*; D004947:Esophagus / Q000502:physiology; D005385:Fingers / Q000098:blood supply*; D006801:Humans; D006979:Hyperthermia, Induced / Q000009:adverse effects; D007036:Hypothermia, Induced / Q000009:adverse effects; D007101:Immersion / Q000009:adverse effects; D017078:Laser-Doppler Flowmetry; D008297:Male; D008991:Monitoring, Physiologic; D013997:Time Factors; D014664:Vasodilation / Q000502:physiology*