Cold Therapy or Cryotherapy
Cryotherapy or cold therapy is a widespread treatment modality used by physiotherapists to treated chronic and acute conditions of differing kinds. It is safe if regard is taken of the indications and contraindications and it is simple to use and to teach patients to self manage their pain problems. Sports physiotherapists and other physiotherapists managing acute injuries use cryotherapy due to its ease of use and lack of expensive equipment needed. The contraindications and indications to ice or cold treatment should be familiar to the physiotherapist before use. Cold water, cold packs, crushed or cubed ice may be used.
Ice therapy cools the local tissues by carrying away heat from the body as the ice melts or the cold water warms. The main physiological effects of cold therapy include decreasing the local metabolism, vasoconstriction, circulation increase in reaction to cold, reduction in oedema and swelling, decrease of any haemorrhage, reduction in muscle efficiency and analgesia secondary to sedation of nerve transmission from the cold. Muscle spasm and spasticity are also reduced as a side effect of pain reduction from the cold application.
There are many tissue based effects which are promoted by the application of cold therapy and these include post-injury reduction of swelling and oedema, a time-related reduction in spasticity once the cold has been applied for some time, an increase in the local circulation, lowering of the acute inflammation which follows tissue damage, muscle spasm reduction, and pain inhibition. Muscle contraction can be facilitated by a physiotherapist using cold therapy and this can be used to improve muscle contraction to increase joint ranges of motion after injury.
In an acute injury cold is to be preferred as compared to heat because the local tissue metabolism will be increased due to the injury, bringing increased circulation, heat and tissue oedema to the area. Application of cold reduces the inflammatory response, reduces pain, limits oedema and reduces the local metabolic rate, controlling the overall response and allowing a quicker resolution of the injury. To be most effective the cold should be applied as soon as possible after the injury along with compression. Compression has been shown in research to be the more important part of acute injury management but cold is still useful.
As with all therapies there are risks involved in applying cold to the skin and these should be understood before using this therapy. Physiotherapists know the contraindications to cold therapy and assess the area for normal sensation, unbroken skin and normal skin texture and colour. Oil applied to the skin can protect against the amount of cooling and reduce the skin risks. An ice pack is typically used, crushed ice being placed in a towelling bag which is then placed snugly around the body part. The towelling should be wet or cooling will be limited and any air gaps between the ice pack and the skin will again reduce the cooling effect.
Convenient and cheap home cold application is often performed using a pack of frozen peas but these should be used with caution as they come out from the freezer at -18 degrees centigrade and this could result in skin injury. This temperature is too low for direct skin application and a wet cloth should always be interposed between the skin and the pack to avoid the chance of frostbite which is cold-mediated local skin damage. From five to twenty minutes is the typical application time used and the skin should be checked after five or ten minutes to make sure skin reaction is normal. Small white spots appearing on the skin indicate overcooling and treatment should stop.
Pain after operative intervention or acute injuries are good subjects for cold therapy in the first two days after onset to control inflammation and pain. Areas of altered skin sensibility should be avoided as they may react abnormally and other contraindications are arterial insufficiency, cold allergy, Reynauds syndrome and lower limb ischaemia. Physiotherapists use various techniques including cold packs, water immersion, contrast baths, spray and stretch and massage with ice. Myofascial pain syndrome trigger points are treated with spray and stretch.