Forekomsten av nedsatt blodsirkulasjon i ekstremiteter hos norske soldater ved kuldeeksponering - en litteraturstudie

Everybody has experienced the discomfort with cold hands and feet. This is worst for those who have a reduced ability to withstand the cold and who also have a profession where the hands are constantly exposed to cold environments. In a project about endurance, one of the tasks was to identify the individual cooling differences of the extremities. Increased contractions of the small blood vessels in the extremities induced by cold exposure are known as Raynaud’s phenomenon (RF). In Norway, RF is often called “white fingers” or “dead fingers” due to the pallor color changes of the fingers often occurring during attacks. Especially the fingers and toes are stricken by this. Because the blood transports the heat out to the fingers, the finger temperature will drop dramatically when the blood stream is reduced. Cooling down of the hands can lead to loss of basic skills that are critical for soldiers both in training and battle, such as zipping, boot lacing, raising a tent and handling weapons. Reduced blood circulation can also give increased risk for cold injury, especially frostbite in the fingers. Since Raynaud’s phenomenon (RF) is a discomfort that can be significant for our soldiers’ operational capability, and as there has not been any reviewed information about this phenomenon in the military context, we chose to go to through the literature on the prevalence of RF and the risk factors associated with this phenomenon. The intention is to obtain better knowledge of RF in addition to more knowledge about the Norwegian soldiers’ individual differences in cold sensitivity, so that action, if necessary, can be implemented. The results pointed out in this report are taken from international studies. The studies show that RF is a common phenomenon and that the prevalence in the general world population is about 5 %. The prevalence is possibly higher in Norway, since studies show the largest rate of RF in countries with cold climate and long winter seasons. The condition affects young healthy women between 15 and 40 years, and the reason is assumed to be a local abnormal strong reaction from the nervous system when exposed to cold temperature or emotional stress. To prevent an RF attack it is important to avoid freezing and to protect the hands and feet from cold exposure. Attacks can occur in environmental temperature up to 16 °C in all seasons. The whole body must probably be cooled down to induce mild attacks, which are most likely to occur among soldiers. It is recommended to avoid the use of nicotine, especially snus, because snus leads to a strong reduction of the blood circulation in the hands. A better knowledge about the individual differences in the blood circulation can prevent cold injuries among future recruits and give support to any new initiative for better securing of the optimal dexterity for soldiers. It is recommended that the ability to withstand the cold is implemented in today’s examinations of the Norwegian recruits.