Cryotherapy is the local or general use of low temperatures in medical therapy. Cryotherapy is used to treat a variety of benign and malignant tissue damage, medically called lesions. The term "cryotherapy" comes from the Greek cryo (κρύο) meaning cold, and therapy (θεραπεία) meaning cure. Cryotherapy has been used as early as the seventeenth century.
Its goal is to decrease cell growth and reproduction (cellular metabolism), increase cellular survival, decrease inflammation, decrease pain and spasm, promote the constriction of blood vessels (vasoconstriction), and when using extreme temperatures, to destroy cells by crystallizing the cytosol, which is the liquid found inside cells, also known as intracellular fluid (ICF). The most prominent use of the term refers to the surgical treatment, specifically known as cryosurgery. Other therapies that use the term are cryogenic chamber therapy and ice pack therapy.
Hyperbaric gaseous cryotherapy
- Muscle relaxation
This technique, practiced by some doctors, physiotherapists and veterinarians consists in applying for a short time on the skin up to the painful area, carbon dioxide at −78 °C with a pressure of 50 bars and a frequency of 400 Hz. Sessions can be repeated at will. Unlike ice packs, the usage of carbon dioxide does not produce pain. Even if not as dangerous as liquid nitrogen used in cryosurgery, the low temperature could cause burns.
Cryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. Cryotherapy is used to treat a number of diseases and disorders, most especially skin conditions like warts, moles, skin tags and solar keratoses. Liquid nitrogen is usually used to freeze the tissues at the cellular level. The procedure is used often because of its efficacy and a low rate of side effects.
Ice pack therapy
Ice pack therapy is a treatment of cold temperatures to an injured area of the body. An ice pack is placed over an injured area and is intended to absorb heat of a closed traumatic or edematous injury by using conduction to transfer thermal energy. The physiologic effects of cold application include immediate vasoconstriction with reflexive vasodilation, decreased local metabolism and enzymatic activity, and decreased oxygen demand. Cold decreases muscle spindle fiber activity and slows nerve conduction velocity, therefore it is often used to decrease spasticity and muscle guarding. It is commonly used to alleviate the pain of minor injuries, as well as decrease muscle soreness. The use of ice packs in treatment decreases the blood flow most rapidly at the beginning of the cooling period, this occurs as a result of vasoconstriction, the initial reflex sympathetic activity. As stated previously, ice is a very popular modality for treatment in injuries and muscle repair following any activity, however the application of cold prior to activity is also an option, and is often used in sports medicine.
Ice is not commonly used prior to rehabilitation or performance because of its known adverse effects to performance such as decreased myo-static reflex and force production, as well as a decrease in balance immediately following ice pack therapy for 20 minutes. However if ice pack therapy is applied for less than 10 minutes, performance can occur without detrimental effects. The physiological effects that the body goes through after cold therapy application include initial vasoconstriction, shunting all blood away from the body part, followed by vasodilation, as blood flows back to the affected area in attempt to re-warm. If the ice bag therapy is removed at this time, sportsmen are sent back to training or competition directly with no decrease in performance.
Cryogenic chamber therapy
According to Costello et al, a relatively new modality of cryotherapy, called Whole Body Cryotherapy (WBC), is currently being offered by clinicians as an alternative to cold water immersion or ice packs. Administered through the use of a cryogenic chamber, WBC is a treatment whereby the patient is placed in a cryogenic chamber for a short duration (i.e. no more than three minutes, which is comparable to ice swimming), and if used properly, will not destroy tissue. Whole body cryotherapy originated in Japan in 1978. However, it was a group of Polish scientists who took the idea and made whole body cryotherapy the physical therapy it is today. The Olympic rehabilitation centre in Spala, Poland opened in May 2000 and has been used as a training and injury rehabilitation centre for many sporting bodies.
The chamber is cooled, typically with liquid nitrogen, usually to a temperature of −120 °C (−184 °F)—although temperatures of −140 °C (−220 °F) or even −160 °C (−256 °F) have been used. The patient is protected from acute frostbite with socks, gloves and mouth and ear protection, but in addition to that, wears nothing but a bathing suit. The patient spends a few minutes in the chamber. During treatment the average skin temperature drops to 12 °C (54 °F), while the coldest skin temperature can be 5 °C (41 °F). The core body temperature remains unchanged during the treatment, however it may drop slightly afterwards. Therapy triggers the release of endorphins which induce analgesia (immediate pain relief).
Patients report that the experience is invigorating and improves a variety of conditions such as psychological stress, insomnia, rheumatism, muscle and joint pain, fibromyalgia, itching, and psoriasis. The immediate effect of skin cooling and analgesia lasts for 5 minutes, but the release of endorphins can have a lasting effect, where the pains and signs of inflammation as found in blood tests remain suppressed for weeks. The effects of extreme cold and endorphin release are scientifically studied. Curiously, some patients compare the feeling to sauna at 110 °C (230 °F). Wales rugby union international Sam Warburton, who along with his teammates used the Spala facilities whilst training for the 2011 Rugby World Cup, has dubbed the chambers "evil saunas", but added:
I'd be lying if I didn't say it was a pretty savage experience, but the other side of the coin is that it is definitely working and allowing us to train in a way that would be impossible under normal conditions.
Cryotherapy and headaches
A study published in the September 2000 edition of the Archives of Family Medicine showed that a combination of pressure and cold temperatures can successfully mitigate headache-related pain and also decrease the duration of a headache. Eighty-seven percent of participants (p=.004) said that the combination of pressure as well as temperature therapy was "optimally effective"; 13% said that the temperature therapy was "moderately effective". Many products exist that provide temperature therapy, many times cryotherapy, to combat headaches.
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- Cryotherapy at the US National Library of Medicine Medical Subject Headings (MeSH)
- eMedicine.com – Dermatology – Cryotherapy
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- Rugby World Cup 2011: How cryotherapy chamber allowed Wales to come in from the cold