Monday, January 31, 2011

Don’t Get ‘Bitten’ by the Frost!

With Mother Nature’s most recent gift of ice and snow, it seems fitting that we talk about a cold related emergency: frostbite! Historically, frostbite was known to be a problem suffered only by military personal and hunters, who spent hours in sub-freezing temperatures due to the nature of their profession; however times have changed and civilians are now included in those at risk.

Frostbite occurs when tissues freeze after being exposed to temperatures below the skins ‘freezing mark,’ which is 2 degrees Celsius. Those individuals most susceptible still include military personal and hunters, but also include those of us who spend large amounts of time outdoors; whether that be all-terrain hikers, sanitation workers or recreational skiers. Other individuals most susceptible include those who are dehydrated, malnourished, intoxicated or elderly. Parts of the body that are most affected include areas that protrude from the body, meaning ones fingers, toes, ears, nose and cheeks!

There are two mechanisms by which tissues can freeze resulting in frostbite:

  1. Directly: As the tissues are exposed to colder and colder temperatures ice crystals form within the tissues causing the surrounding cells to lose some of their water content (dehydrate). The state of dehydration leads to breakdown of the cell structure and results in frostbite.
  1. Indirectly: Known as the “hunter’s frostbite,” this mechanism occurs when there is increased blood flow to the freezing tissues followed by decreased blood flow, and increased blood flow again. The alternating blood flow leads to inflammation and damage to the small vessels within the affected tissue, which in its most advance stages leads to inability for blood to reach those sites indefinitely, i.e. frostbite!

Whichever mechanism of ‘freeze’ causes the frostbite, symptoms typically present in the same fashion. Initially burning, numbness, tingling and/or itchiness in the affected area occurs, warning of impending freeze. When these sensations are experienced it’s best to get inside and warm up for a bit before heading back out into the cold temperatures. However, if you don’t notice these symptoms, or fail to heed their warning, progression of your ‘tissue freeze’ will continue. The affected areas will begin to turn white, there will be an absence of sensation and swelling will occur. In severe cases, blistering of the affected area occurs with purplish/blue color changes and hardening of the tissue or a “wooden” feeling to the skin. It is at this end-point that the danger of losing the affected part becomes reality.

Classically, four stages of frostbite have been described from 1st degree being the most benign and resulting in no permanent injury or tissue damage to 4th degree frostbite being the most harmful with complete tissue death and loss of the affected part. There are also categories of frostbite such as Chilblain’s and Frostnip that don’t fall into one of the four stages, and are characterized as milder forms of the typical frostbite. In any situation, if you are even the tiniest bit suspicious of frostbite, it is important to seek medical attention immediately. Treatment, including controlled/monitored rapid re-warming of the affected area will help save as much tissue as possible.

Frostbite is not an injury you want to suffer from so prevention is key, but if you find yourself in a situation where frostbite seems probably remove yourself from the cold temperatures immediately and seek medical attention for evaluation and appropriate treatment.

Protect those areas most at risk by bundling up with gloves or mittens, hats, earmuffs, wool socks and water proof shoes next time you head out to shovel your sidewalk or make snow angels in some fresh powder!