Cold and compression are routinely applied immediately after acute injury or following surgery to alleviate pain, reduce swelling and speed functional recovery.
Because the benefits of cold compression therapy diminish with time, this intervention is thought to be most effective if applied almost immediately after injury or at the conclusion of an operative procedure.
The local application of cold suppresses the metabolic rate of the immediately surrounding soft tissue. This decrease in tissue metabolism is associated with a reduction in enzymatic activity, preventing tissue damage caused by hypoxia. Local hypothermia induces vasoconstriction and lowers microcirculation by more than 60%, an effect that can persist for up to 30 minutes after cessation of cooling. Cold-induced vasoconstriction reduces extravasation of blood into surroundings tissues, local inflammation and edema production. The amelioration of pain associated with the direct application of cold to injured tissue is, in part, related to the reduction in edema formation as well as to decreases in motor and sensory nerve conduction.
A reduction in blood flow and swelling also can be achieved with compression by facilitating translocation of edema away from the site of injury and toward proximal noncompressed tissues where it can be resolved more efficiently by the lymphatic system. Importantly, the addition of cold to compression increases the rate, magnitude and depth of temperature reduction, as well as the speed of lymph evacuation