Cold Air Therapy
This article comes from the CryoOne Cold Air Therapy Book (art.nr. 13442251-40_)
Click here to download the CryoOne Cold Air Therapy Book
Therapeutic effects of cold applications
Short, sharp cooling initially causes vasoconstriction which is followed, once finished, by vasodilatation.
This is particularly evident in the skin. The serial application of cold stimuli stimulates vasomotor function involving a training effect on vascular dynamics because vasodilatation after cooling perceptibly heats the treated area via reactive hyperemia.
Short bursts of cold air to the trunk act as a strong reflex stimulus for systemic metabolic activity, with generalized improvement in the peripheral microcirculation and thus, warming, as is known from use in Kneipp therapy. In addition to the local effects on vasomotor function mentioned, cold air also has a two-stage systemic effect, particularly when applied to the trunk. This is characterized by an initial stimulation of respiration, an increase in blood pressure and cardiac activity followed by calming. This also occurs when cold stimuli are applied to the extremities but the latter must be warm.
If cold stimuli are applied to cool/cold extremities, the microcirculation and metabolic activity are further reduced, even deep inside, and the patient develops frostbite. Care must therefore be taken to ensure that frostbite does not occur, particularly when applying cold air to the extremities. If need be, the areas adjacent to the portion of the limb being treated must be covered to be kept warm, in order to prevent the dissipation of heat from the area inadvertently cooled. Contrastingly, the application of considerable cold stimuli to the face must be avoided unless there has been prior acclimatization, because this may lead to short-term apnea (diving reflex) with an increase in pressure in the chest (Valsalva maneuver) and to a considerable rise in blood pressure due to generalized constriction of the resistance vessels. The eyes should also be protected against cold air. In the case of acute inflammation, associated with local heating, among other things, cold air is a preferred method of pain control and prophylaxis of edema.
For an initial ergotropic (sympathicotonic) situation, cryotherapy is ideally administered to the back for its general soothing properties and to promote sleep. This is in direct contrast to the relaxing, refreshing effect of mild cooling in an initial trophotropic (vagotonic) situation, especially of the face and neck region.
Other effects include
- Alleviation of mechanically, biochemically or infection-induced inflammation
- Reduction in inflammation activity
- Decrease in nerve conduction velocity
- Inhibition of nociception (pain generation) and pain conduction as from 13 °C
- Blockade of nerve conduction from 8 °C
- Diminished metabolic activity
- Release of pain-inhibiting neurotransmitters
Effect on muscle tone
- Short cold stimuli increase the activity of the muscle spindles and lead to an increase in muscle tone.
- Long cold stimuli reduce the activity of the muscle spindles and lead to a decrease in muscle tone and muscle spasticity
- Decrease in the nerve conduction velocity of motor fibers
- Immediate, persistent constriction of local superficial blood vessels through stimulation of the noradrenergic nerve endings in the vessels
- Immediate, general vasoconstriction (even at depth) via CNS reflex arcs
- Delayed, generalized vasoconstriction through activation of the posterior portion of the hypothalamus due to the return of cooler blood
Vasodilatation below a tissue temperature of 15 °C
- Temperature-dependent approximately 2 – 6 minutes after beginning cold therapy (as a protective function triggered by vasomotor “paralysis” of arteries, arterioles, veins, venules and lymph vessels)
- Wave-shaped fluctuations in blood flow during long-term cooling (from approximately 30 minutes)
Autonomous nervous system
- Increase in blood pressure and tachycardia with the sudden onset of the cooling action
- Bradycardia following the application of cold therapy to the face
Activating respiration and O2 consumption
- Especially on applying a current of cold air to the trunk (chest and back)
- Metabolic activity in the muscles and joints
- Slowing down of metabolic rate in cooled tissue and reduced O2 consumption
- Diminished enzyme activity in inflammatory processes, consequently inhibition of breakdown of cartilage, for example
- Inhibition of the release of algogenic agents (e.g. catecholamines, histamine)
- Reduction in the conduction velocity and impulse frequency of pain-conducting nerve fibers
- Onset of analgesic effect at approximately 13 °C (pain receptor temperature)
- Nerve blockade from approximately 8 °C (nerve temperature)
Non-contact cooling is an important therapeutic property of cold air therapy. The amount of water vapor in the air decreases as the temperature drops such that the cold air of the CryoOne, with a starting temperature of up to -35°C, represents dry treatment.
This minimizes the risk of frostbite.
The production of ice on the skin by freezing the moisture from the swirling surrounding air is likewise impossible since the air current prevents stationary condensation.
More to know (consult the therapy book)
- Cold air vs Cool spray vs Ice bags
- Reactive hyperemia
- The general guideline for avoiding reactive hyperemia
- Distance between the nozzle and the skin
- Biologically effective indications taking the wind chill effect into account
- Sudeck’s disease
- Post-stroke spasticity
- Subacromial impingement syndrome,
- humeroscapular periarthritis
- Muscle injury
- Thoracic spine pain
- Sprained ankle
- Status post cruciate ligament reconstruction
- Low back pain
- Neck-shoulder-arm syndrome
- Rheumatoid arthritis
- Inguinal pain
- Multiple sclerosis
- Piriformis syndrome
- Spasmodic torticollis