Following completion of this chapter, the student will be able to:
- Appraise the effectiveness of external compression on the accumulation and the reabsorption of edema following an athletic injury.
- Outline the setup procedure for intermittent external compression.
- Recognize the effects that changing a parameter might have on edema reduction.
- Review the clinical applications for using intermittent compression devices.
Edema accumulation following trauma is one of the clinical signs at which considerable attention is directed in first aid and therapeutic rehabilitation programs. Edema is defined as the presence of abnormal amounts of fluid in the extracellular tissue spaces of the body. Intermittent compression is one of the clinical modalities used to help reduce the accumulation of edema.
Two distinct kinds of tissue swelling are usually associated with injury. Joint swelling, marked by the presence of blood and joint fluid accumulated within the joint capsule, is one kind. This type of swelling occurs immediately following injury to a joint. Joint swelling is usually contained by the joint capsule and has the appearance and feel of a water balloon. If pressure is placed on the swelling, the fluid moves but it immediately returns when the pressure is released.
Lymphedema is the other variety of swelling encountered in athletic injuries. This type of swelling in the subcutaneous tissues results from an excessive accumulation of lymph and usually occurs over several hours following the injury. Intermittent compression can be used with both varieties, but it is usually more successful with pitting edema. The lymphatic system is the primary body system that deals with these injury-induced changes.
Purposes of the Lymphatic System
The lymphatic system has four major purposes:
The fluid in the interstitial spaces is continuously circulating. As plasma and plasma proteins escape from the small blood vessels, they are picked up by the lymphatic system and returned to the blood circulation.
The lymphatic system acts as a safety valve for fluid overload and helps keep edema from forming. As the interstitial fluid increases, the interstitial fluid pressure increases, causing an increase in the local lymph flow. The local lymphatic system can be overwhelmed by sudden local increases in the interstitial fluid and pitting edema will be the result.1
The homeostasis of the extracellular environment is maintained by the lymphatic system. The lymphatic system removes excess protein molecules and waste from the interstitial fluid. The large protein molecules and fluids that cannot reenter the circulatory vessels gain entry back into the blood circulation through the terminal lymphatics.
The lymphatic system also cleanses the interstitial fluid and provides a blockade to the spread of infection or malignant cells in the lymph nodes. The lymph nodes' ability is not clearly understood and is highly variable.2
Structure of the Lymphatic System
The lymphatic system is a closed vascular system of endothelial cell–lined...