Cryotherapy, Acute Injury and Pain Control

Cryotherapy is also known as “cold hydrotherapy” and can take the form of ice, frozen gel packs (or a bag of peas) or submersion into cold water. It is most beneficial when an acute injury occurs, and will assist in pain control and reduce swelling and bruising.

Disclaimer:  If you are unsure if or how you should use a cold application, please consult with a medical professional who can take into consideration your personal health history.

We have all felt the pain of sprains, strains or bruises, but did you know that most massage therapists are trained in hydrotherapy applications? These applications enhance the effects of treatment and can be used by clients at home. It is important, though, to know how to use cold applications properly.

Inflammation is known as a “non-specific” response to injury, and is a physiological process which begins immediately after injury.  Inflammation serves the purpose of isolating and immobilizing the injured area. When an injury occurs, whether it is a sprain, strain, contusion etc, a cascade of events is set in motion:

• vasoconstriction (contraction of the blood vessels) occurs immediately, followed shortly by vasodilation (expansion of the blood vessels).  Vasodilation results from the release of chemicals such as histamine, increasing the size and permeability of capillaries and arterioles

• This increase in size and permeability increases blood flow to area (resulting in warmth and redness) and the leaking of fluid (exudate) from capillaries (resulting in swelling and pain)

• with increased blood flow, white blood cells migrate to area – the presence of white blood cells will inhibit infection

• At this point, further loss of blood and fluid is prevented due to clotting by proteins

Even though inflammation does serve a purpose, it can be very painful. This is where cold hydrotherapy applications come in handy, as they help control pain and bruising of injured tissue.

How does the application of cryotherapy affect an injury?

When cold is applied, the sensation which is felt is Cold, then Burning, Aching and Numb. (CBAN) The general rule when applying cold to an acute injury is to leave the application on until the area is numb, or for 10 minutes, whichever comes first.  This duration of application, which is considered to be a “long” duration, will have the following effects on tissue:

• slowdown metabolism of the affected cells, meaning less oxygen is required for cellular process

• cold will constrict the blood vessels and decrease blood flow, thereby reducing hematoma and contusion formati

• the exudate (fluid) formation will be reduced at the site; less fluid puts less pressure on the pain receptors – therefore, it is less pain

• This effect will last up to 20 minutes after the application has been removed

• pain decreases for 2 reasons:   waste products (cellular debris) is being absorbed and cold has a numbing effect on the nerves (pain receptors or nociceptors)

Cold hydrotherapy applications during this phase of injury may also decrease the amount of scar tissue formed, as the migration of fibroblasts to the injury site is reduced.

Why is there a time limit on how long I can leave a cold application on?

The time limit which is placed on a cold application is there to maintain the health of the tissue. If cold is left on an area for too long (12-15 minutes or longer), Hunting Response is activated to prevent tissue damage from prolonged cold.

Hunting Response is a cycle of vasoconstriction (decreased blood flow), then vasodilation (increased blood flow), and will occur if cold is left on for too long, or when tissue is cooled excessively. The increased blood flow occurs for 2 reasons:

1) to prevent damage to tissue that is peripheral to the injury site and

2) to help remove waste products,such as histamine, which occur in response to the injury and to the cold.

Hunting Response is essential to tissue health as it maintains the cellular metabolism at a rate which assists in healing the injury and surrounding tissue, and ensures that blood, supplying oxygen and nutrients, is delivered in adequate amounts to the cells.

If Hunting Response is allowed to occur from a prolonged application of cold, it can be painful as blood is forced into the area via a process known as “active derivation”.

How do I use a frozen gel-pack on my injury?

Gel packs are just one of several cryotherapy applications, and are a convenient way to address an acute injury.  Here are some tips, precautions and contraindications for using cryotherapy:

1. Any application is contraindicated over an open wound, as it may introduce infection to the area.
2. Cold applications should be left until after your massage therapy treatment, and can be used between visits.
3. Cold should never be applied “proximal” to an injury. (proximal is an anatomical term which refers to how close an area on a limb is to the trunk of the body. For example. the elbow is proximal to the hand.)  Circulation is diverted away from the application site, and blood may pool in the already injured area.
4. Cold is contraindicated if you have had a previous poor reaction to cold, have nerve damage, poor circulation (such as in diabetes or Raynaud’s Disease), fragile skin, plates, pins or wires.
5. Your gel pack should always be wrapped in a damp cloth or towel, and not applied directly to the skin. (you can damage your skin this way)
6. The gel pack can be used in cycles of 10-10-10 – 10 minutes on, 10 off, 10 on again.  Then, give your body a rest and leave it off for up to an hour, then repeat.
7. You should never lie on your gel pack.

For further information on hydrotherapy, the book I used as a reference for this article is An Introduction to Heat and Cold as Therapy by Laurel Fowlie (paperback 2006)

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