CYCLOTHERM

WHAT IS CYCLOTHERM? 1

Cyclotherm is a device which can heat or cool the skin surface by means of varying the temperature of a circulating fluid.

This system is able to apply a temperature up to 40°C and down to 1°C and vary it between these limits at a rate of approximately 13°C per minute.

A flexible applicator, in which fluid circulates, is held in contact with the tissue surface.

The device can be programmed to apply predetermined temperatures for pre-set times for thermotherapy, cryotherapy and, perhaps most usefully, thermal contrast therapy

CONSTRUCTION 2

It comprises a water reservoir to which water is added and that is then connected, via an insulated tube, to a sleeve or sealed bag-like unit.

The water circulates through the bag which covers the area being treated.

Depending on the unit, the water is kept at a thermostatically preset temperature (controlled temperature flow) or flaked ice is added to the water in the reservoir so water at or close to 0°C is circulated.

The water is either pumped through continuously by an electric pump (continuous flow) or is circulated by flushing it back through the reservoir every 15 minutes or so (intermittent flow)

PHYSIOLOGICAL EFFECTS

Heat : Increase circulation Increase metabolism Increase inflammation (↑ phagocytosis and

wound healing) Decreased pain (analgesic effect)

general sedative effect that promotes relaxation, effective for general soreness, aches, pain, but not as effective as cold application in removing acute injury pain

Decrease muscle spasm Decrease tissue stiffness

Cold : On cutaneous blood vessels

There is immediate vasoconstriction of cutaneous blood vessels, this restricts the blood flow in the skin so that heat loss is minimised

On muscle blood flow Cooling provokes vasoconstriction in all vascular

smooth muscles and the increased viscosity leads to reduced flow of blood

Lowered metabolic rate Reduced O2 uptake Reduced production of metabolites Reduced cellular activity Slowed healing

On PNS Cold applied to the skin provides a strong sensory

stimulus by stimulating cold receptors Effects seen on PNS due to reduced nerve

conduction: reduction of Pain Hypertonicity

Muscle strength – variable effect

THERAPEUTIC USES

Heat : Therapeutic heat is most effective in

decreasing general soreness and in preparing soft tissues for stretching and joint mobilisation

To increase blood flow to the injured body part; during this process blood also delivers nutrients to that area and carries metabolites and other waste products, thereby increasing the rate of healing of the injury

Cold : Applied to recent injuries

Limits bleeding by vasoconstriction and increased blood viscosity

Pain relief Reduces the conduction of cutaneous nociceptive

fibres Reduces muscle spasm Reduces muscle spasticity Facilitates muscle contraction Reduction of chronic inflammation and joint

effusion

THERAPEUTIC EFFECTS OF THERMAL CONTRAST THERAPY 3

Facilitates a mild tissue temperature increase Stimulates circulation Increases circulation in the contralateral

extremity due to the crossover phenomenon Produces increased blood flow to the involved

area Produces hyperemia by alternating

vasodilatation and vasoconstriction of the superficial blood vessels

Relieves stiffness and pain Reduces necrotic cells and aids healing Reduces inflammation and pitting edema Decreases stasis and scar tissue Improves range of motion Provides a transition for tissue accommodation

between immediate cryotherapy and later thermotherapy treatment

INDICATIONS

Heat Connective tissue contracture (2 weeks or

longer) resulting from immobilisation must be treated with heat followed by stretching and mobilisation

Sub-acute joint sprains (4-14 days post injury) that remain sore but allow the patient to exercise should be treated with heat before exercise and with cold afterward

Cold Immediate care of acute injuries Facilitating exercise during rehabilitation of

orthopaedic injuries Muscle spasm with cold and stretching is

relieved faster than with heat and stretching

CONTRAINDICATIONS

Vasospasm or any kind of vascular disorders such as arteriosclerosis

Cryoglobinaemia – abnormal protein present in blood, which precipitates at low temperatures, blocking blood vessels and causing local ischaemia

Cold urticaria – cold causes release of histamine from mast cells leading to local erythema and sometimes symptoms like lowered BP and raised pulse rate

Special care with: Cardiac disease Hypertension Loss of sensation Emotional and psychological features

Malignancies Loss of sensation Infection

BENEFITS 2

Continuous-flow cryotherapy has been proved to decrease pain, inflammation, swelling, blood loss, and narcotic usage in the postoperative setting.

COMPLICATIONS 2

Complications include frostbite, chronic pain, and loss of digits.

Continuous-flow cold therapy should be discontinued when capillary refill time is greater than 5 seconds.

There is some evidence that the additional compression of a brace or strap over a flow bag can increase the risk of skin damage.

REFERENCES

1. Low and Reed – 3rd edition2. Low and Reed – 4th edition: Continuous flow

cryotherapy units3. J. William Myrer , 1994 – Contrast Therapy

and Intramuscular Temperature in the Human Leg

Thank You