2007, Piran, Slovenia

Invited presentation
FINGER COLD INDUCED VASODILATION
Hein Daanen
TNO Defence, Security and Safety, Soesterberg, The Netherlands
Contact person: hein.daanen@tno.nl
Cold physiology
INTRODUCTION
In 1930 Lewis observed an unexpected rise and fall in finger skin temperature after several
minutes of finger immersion in ice water (Lewis, 1930). The last decade there is a renewed
interest in Cold Induced Vasodilation (CIVD), in particular since it may be related to the risk
for cold injuries (Daanen and Van Der Struijs, 2005) or manual performance (Geurts et al.,
2005a).
CIVD MECHANISM
The mechanism responsible for CIVD is still subject to debate. Lewis (1930) proposed that
the axon reflex was responsible, but this is not likely since axon reflexes cannot be evoked in
cold hands (Daanen and Ducharme, 2000). The most likely hypothesis is that the
neuromuscular transmission between the sympathetic nerve ending and the arterio-venous
anastomoses (AVA) is reduced in cold, leading to ‘paralysis’ of the strong muscular coat of
the AVA and subsequent increase in blood flow. Inhibitors of nitric oxide synthesis may play
an important role in the magnitude of the CIVD response (Noon et al., 1996).
FACTORS INFLUENCING CIVD
Several factors influence the magnitude and reproducibility of finger CIVD. First, the cooling
medium is important. Water from 0 to 5ºC seems to give the most reproducible results. CIVD
can be evoked in cold air or by touching cold materials, but not in a reproducible manner.
CIVD response is reduced at altitude, but recovers partly after several weeks of altitude
residence (Daanen and Van Ruiten, 2000).
Core temperature and/or body heat content has a strong effect on CIVD magnitude. When
hypothermic, heat is preserved in the body to prevent further cooling. There are some
indications that finger CIVD response can be improved by repeated cold-water immersions
(Adams and Smith, 1962), but other studies seem to show the opposite (Geurts et al., 2005b).
Several experiments are currently running to get a clearer image of the training potential.
The CIVD response differs between ethnic groups and age groups; gender differences are
small. Studies indicate that food, exercise and stress modify the CIVD response, but the
hydration status of the body does not seem to play a major role (O'Brien and Montain, 2003).
Surprisingly, smokers generally seem to have a better CIVD response than non-smokers
(Daanen and Van Der Struijs, 2005;Miland and Mercer, 2006).
When the most important factors influencing CIVD are controlled, the temperature response
of the skin of the finger tip to cold water immersion appears to be reproducible (Meehan,
1957;O'Brien, 2005).
BENEFITS OF CIVD
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