What is Cold or Cryo Therapy In Physiotherapy?

Cryotherapy, which literally means “cold therapy,” is a technique where the body is exposed to extremely cold temperatures for several minutes. The application of cold to the tissues after the injury is a practice as old as medicine itself. 

Cryotherapy can be delivered to just one area, or you can opt for whole-body cryotherapy. Localized cryotherapy can be administered in several ways, including ice packs, ice massage, coolant sprays( instant evaporation of volatile fluids), ice baths, and even through probes administered into the tissue. often the skin temperature is being reduced as low as 10-degree Celcius.

Ice therapy is used to Reduce pain, Reduce spasticity, Reduce muscle spasm, and Reduce swelling to promote the healing and repair process of tissue so that such a sensation can provide excitatory stimulus when muscles are inhibited.

Principles of CRYOTHERAPY

Cryotherapy works on the Principle of latent heat, which suggests that a specific amount of energy is required to change the solid(i.e., ice) form of a particular substance into Liquid, or the liquid into gas. this energy is called latent heat in the case of water, as we are using ice in cryotherapy. 

the latent heat of fusion says that 1 gram of ice at 0degree Celsius requires 336 joules of energy to convert it to 1 gram of water at 0 degrees Celcius. whereas on the other hand, latent heat of vaporization says that 1 gram of water requires 2268 joules of energy to convert it to 1 gram of steam at 100 degrees Celcius. as per matter changes from a state of steam to water, and water to solid this latent energy is released. whenever we applied ice on the skin, ice melts, and melting on the skin takes considerable energy from skin.

so when you are trying to reduce temperature ask your patient to use ice instead of cold water because cold water won't be that effective to take energy from the body.

Physiological effects and USES

Improved Circulation.

the initial response to the ice of skin will be local vasoconstriction to preserve the heat of the skin. this homeostatic response has the effect of allowing the part to become very cold. after a very short time vasoconstriction is followed by vasodilation then alternate vasoconstriction and vasodilation and duration are depending on the area involved. this apparent hunting for the mean point of circulation is called Lewi's hunting reaction. during the period of vasodilation, the arteriovenous anastomosis is closed, thus causing an increased blood flow through capillaries. this is beneficial in the treatment of swelling and tissue damage.

Physiotherapeutic uses of circulatory effect 

1. The initial vasoconstriction is often used to limit the extravasation of blood into the tissues following injury, e.g. sports injuries. Ice therapy is then usually followed by some form of compression bandage. 
2. 2. The alternate periods of vasoconstriction and dilatation affect the capillary blood flow, and it is across the capillary membrane that tissue fluid and metabolic exchanges take place. Consequently, an effect is being produced at a very local level which can reduce swelling: excess tissue fluid can be removed from the area and returned to the systemic circulation. Increased circulation allows more nutrients and repair substances into damaged areas. Thus ice is very useful in removing swelling and aiding repair. For instance, ice - cube massage may be used to accelerate the rate of repair of bedsores. 
3. The reduced metabolic rate of cooled tissues ( van't Hoff's law ) allows the cooled muscle to contract many more times before fatigue sets

What is Neural Response of skin?

our skin contains a lot more cold receptors then warm receptors. the cold receptors respond to cooling by the sustained discharge of impulse. 

It is detailed science behind the effects of cold therapy.  the main effect which quite effectively has been observed is the Reduction of pain and reduction of Spasticity. also it is quite helpful postoperatively or in nerve-related conditions.

Techniques of application.

how ice is applied will vary according to the effect required. it may be applied in the so many forms,

• Ice towels
• Ice packs
• Immersions
• Ice cube massage
• Excitatory cold(quick icing)

Ice towels

Ice towels are majorly used for instant relief of stress and pain in athletes.

Application Of Ice towels 

1. The excess water is pulled from one towel, leaving as much ice as possible clinging to it. It then applies to the part to be dealt with.

2. The towels are changed when they are at least 30 seconds in position, but not more than 2 minutes.

3. Up to ten towels can be applied in a row; more if the physiotherapist considers that they are beneficial, i.e. the total treatment time is 15-20 minutes.

Changes to technique

In the presence of swelling, elevating the limb and surrounding the joint with the ice towels is permissible. The patient can exercise in position with the towels. Manual resistance techniques can also be applied by the physiotherapist with the towels in position. The towels are applied during the treatment of spastic muscles along the length of the muscle from its origin to its insertion and the physiotherapist applies appropriate relaxation/facilitation techniques.

Ice packs 

Crushed or flaked ice can be inside a specially crafted towel bag or an ice towel folded in a suitable shape. nowadays icepacks are coming in both one time use and reusable form, where manufacturers are using gel instead of water to make ice more effective for prolonging the time of treatment.

Preparing the bed

A gutter made of polythene sheet is folded and placed on the bed. Under its edges is placed a folded towel to channel the water produced from the melting ice into a container on the side of the bed. The gutter is placed underneath the part to be treated.

Preparation of the patient 

The part to be treated is exposed and placed over the prepared gutter in a comfortable position. A vegetable or nut oil is spread across the skin on which to place the ice pack. This is to try to avoid ice burning, Ice burning is produced by super-skin cooling. This can happen if the pack accumulates water between the pack and the skin, absorbs salts from the skin, and becomes very cold. The oil layer causes the water produced by the melted ice to run out of the skin and into the gutter quickly and easily, thus avoiding super-cooling. The melting of the ice is an essential part of the treatment since the water produced carries heat from the skin to the ice inside.

Application 

The wet ice pack is placed on top of the treatment part. Packs should never surround a limb as this would inevitably put pressure on one side of the limb and reduce local circulation. Reduced circulation would prevent a normal circulatory reaction to cooling and could lead to ice burning. The pack can remain in position for 10 to 20 minutes. Immersion is a technique in which an ice solution immerses the part to be treated. Unfortunately, immersing certain areas such as hands, feet, and elbows are only practical.

Ice - cube massage 

Ice-cube massage is a useful application method because it does not need an ice machine. A domestic refrigerator's freezer compartment is enough. This makes this technique useful in small rooms, wards, and, most importantly, at home.

Preparing

A large block of ice, e.g. frozen water in a yogurt pot, one end is wrapped in a towel, the other end remains free. The patient was exposed and supported appropriately.

Application 

The exposed end of the ice block is circularly massaged over the treatment area, with minimal pressure applied to the part. The maximum application time is 10 minutes. Before this, the desired effect can be achieved.

This technique is especially useful in bed treatment-sores where the ice is gently massaged on the skin around the sore for about 2 minutes. The skin is then gently dried (dabbing or flowing with warm air from a hairdryer). The ice application has been repeated 3 or 4 times. Almost immediately a marked increase in circulation is achieved, and this should speed up repair.

Similar techniques can be applied to pressure areas that threaten to break down, since increased circulation may prevent this.

Excitatory cold 

The marked ice sensory stimulus on the skin can be used to facilitate muscle contraction. First, it is necessary to determine the supply of the inhibited muscle's spinal root level (myotome) and then find the area of the skin that has the same root suppl (dermatome).

Once this is done, the ice over the dermatome is quickly stroked three times and the skin is then dried. This sensory stimulus goes back through the peripheral nerve and through the back horn enters the cord. The anterior horn cells have many connections to these sensory fibers and the net result is an increase in the level of excitation around the anterior horn cell, it is thought. 

The increased excitement may be sufficient to complement the patient's desired effort to contract the muscle. In the case of inhibition or later recovery after a nerve lesion, the 'fast ice' technique is often a useful stimulus to help volunteer muscle contraction.

Contra-Indication for Ice Application

Psychological The idea of ice scares many patients, especially the elderly. Indeed, many claims that the cold makes their condition worse. If the therapist is unable to persuade or show the patient that ice is beneficial, then it may be better not to use it.

Cardiac conditions with myocardial infarction, treatment should be avoided for at least 6 months. The ice application 's initial shock can cause a marked drop in blood pressure, resulting in an increase in heart rate: a weak heart may not be able to meet this demand. The left shoulder and heart have the same sympathetic nerve supply and it has been shown that ice applied to the left shoulder can cause exciting impulses to overflow through these sympathetic nerves to the heart. It is, therefore, necessary to avoid ice on the left shoulder in patients with any type of heart disease.

Peripheral nerve injuries In the area provided by a severe peripheral nerve, blood vessels lose their normal reaction to cooling. If such an area were cooled with ice, the net result would be very cold and it would take many hours to recover normal temperature.

Vasospastic disease Vasospasm is exacerbated by the application of ice in diseases such as Raynaud's. As the cold application can reduce an already inadequate supply of blood, ice is avoided. However, since the tissue also lowered the metabolic rate, it is doubtful whether gangrene would result from cold treatment.

Cold sensitivity Although all precautions are taken, a small number of patients will still have an adverse reaction to ice. These patients produce local histamine after the ice has been applied-like hives that look like nettle rash and itches. These patients are inappropriate for ice treatment.