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by Paulette Rautio (This article is paraphrased from a paper commissioned by MacKinnon Icehorse(tm} continuous Cold Therapy System, authored by David W. Ramey, DVM, and is reprinted with the permission of MacKinnon Inc., www.mackinnonicehorse.com) In human medicine, cold therapy is commonly used to treat acute soft tissue injuries and to help reduce symptoms of inflammation at the end of exercise. In addition, cold therapy appears to have significant analgesic effects and is also used to help alleviate pain in post-surgical patients. Cold therapy can be used in the various phases of pathological processes. In the acute inflammatory phase after soft-tissue injury (up to 48 hours after trauma), cold plays an important role in the control of the inflammatory response. Cold therapy can be used during the repair phase after soft tissue injuries as well (between 48 hours and six weeks after injury). In human medicine, application of cold during the repair phase is referred to as "cryokinetics." The analgesic effect of cold makes it possible to start exercising an injured limb while it is partially desensitized. In humans, this allows early weight bearing on the injured limb at a time when collagen is organizing and remodeling. It's also proposed that motion of the injured limb increases blood flow to the injured area. Cold therapy is a therapeutic option in the treatment of several chronic conditions such as tendinitis, bursitis, trigger points and muscle spasms. Cold therapy is commonly used in the treatment of inflammation and soft tissue injuries in the horse as well. The application of cold has been recommended in the treatment of acute tendon injuries, suspensory desmitis, and laminitis, as well as other non-specific areas of swelling and inflammation. It has also been advocated in pre-exercise therapy. LENGTH OF APPLICATION There appears to be a general consensus in human medicine that the optimum duration of cold therapy is from 20 to 30 minutes. The effects of cold application are seen rather quickly. Investigators using triple-phase technetium-99m scintigraphs (bone scans) were able to show that the topical application of ice for 20 minutes decreased skeletal blood flow in the human knee by an average of 19.3% and soft tissue blood flow by 25.8% (Ho, S.S.W., et al. The Effects of Ice on Blood Flow and Bone Metabolism in Knees. Am J Sports Med 22:537-540, 1994). SUMMARY Clinical studies from human medicine seem to agree that cryotherapy improves recovery from injuries. It should be noted, however, that many of these studies combine cryotherapy with other therapies such as compression, limb elevation and analgesic therapy. Cold reduces the temperature of the tissues to which it is applied; other physiologic processes, such as neuromuscular action, nerve conduction and plasticity of tissues are also affected by cold. It is not clear if it is important to cool injured temperatures to a point near freezing or if more moderate cooling methods are equally effective. Cold may also have negative effects. Increased swelling of the subcutaneous tissues may be seen after application of cold therapy. In experimental situations, cold can increase as well as decrease the inflammatory reaction. Excessive application of cold to tissue has the potential to cause tissue damage or nerve injury. The lower limbs of the horse are almost ideally suited to the application of cold therapy. Because legs are roughly cylindrical, cold can be easily and conveniently applied using a number of different bandaging techniques. Newer technologies make the application of cold easier, more convenient and more effective. There are many applications of cold therapy to equine limbs. However, one common application in human medicine, the use of cold post-surgery, appears not to have been used to a great extent in equine surgery. There appear to be ample opportunities to perform equine-specific clinical research demonstrating the applications of the various techniques of cold therapy to the horse. |