Management of Lymphatic Disorders
The lymphatic system consists of a set of vessels that spread throughout most of the body. These vessels start as lymph capil-laries that drain unabsorbed plasma from the interstitial spaces (spaces between the cells). The lymphatic capillaries unite to form the lymph vessels, which pass through the lymph nodes and then empty into the large thoracic duct that joins the jugular vein on the left side of the neck.
The fluid drained from the interstitial space by the lymphatic system is called lymph. The flow of lymph depends on the in-trinsic contractions of the lymph vessels, the contraction of mus-cles, respiratory movements, and gravity. The lymphatic system of the abdominal cavity maintains a steady flow of digested fatty food (chyle) from the intestinal mucosa to the thoracic duct. In other parts of the body, the lymphatic system‚Äôs function is re-gional; the lymphatic vessels of the head, for example, empty into clusters of lymph nodes located in the neck, and those of the ex-tremities empty into nodes of the axillae and the groin.
Lymphangitis is an acute inflammation of the lymphatic channels. It arises most commonly from a focus of infection in an extrem-ity. Usually, the infectious organism is a hemolytic Streptococcus. The characteristic red streaks that extend up the arm or the leg from an infected wound outline the course of the lymphatic vessels as they drain.
The lymph nodes located along the course of the lymphatic channels also become enlarged, red, and tender (acute lym-phadenitis). They can also become necrotic and form an abscess (suppurative lymphadenitis). The nodes involved most often are those in the groin, axilla, or cervical region.
Because these infections are nearly always caused by organisms that are sensitive to antibiotics, it is unusual to see abscess forma-tion. Recurrent episodes of lymphangitis are often associated with progressive lymphedema. After acute attacks, an elastic compression stocking or sleeve should be worn on the affected extremity for several months to prevent long-term edema.
Lymphedemas are classified as primary (congenital malforma-tions) or secondary (acquired obstructions). Tissue swelling oc-curs in the extremities because of an increased quantity of lymph that results from obstruction of lymphatic vessels. It is especially marked when the extremity is in a dependent position. Initially, the edema is soft, pitting, and relieved by treatment. As the con-dition progresses, the edema becomes firm, nonpitting, and un-responsive to treatment. The most common type is congenital lymphedema (lymphedema praecox), which is caused by hy-poplasia of the lymphatic system of the lower extremity. This dis-order is usually seen in women and first appears between ages 15 and 25.
The obstruction may be in the lymph nodes and the lymphatic vessels. Sometimes, it is seen in the arm after an axillary node dis-section (eg, for breast cancer) and in the leg in association with varicose veins or chronic thrombophlebitis. In the latter case, the lymphatic obstruction usually is caused by chronic lymphangitis. Lymphatic obstruction caused by a parasite (filaria) is seen fre-quently in the tropics. When chronic swelling is present, there may be frequent bouts of acute infection characterized by high fever and chills and increased residual edema after the inflamma-tion has resolved. These lead to chronic fibrosis, thickening of the subcutaneous tissues, and hypertrophy of the skin. This condition, in which chronic swelling of the extremity recedes only slightly with elevation, is referred to as elephantiasis.
The goal of therapy is to reduce and control the edema and pre-vent infection. Active and passive exercises assist in moving lym-phatic fluid into the bloodstream. External compression devices milk the fluid proximally from the foot to the hip or from the hand to the axilla. When the patient is ambulatory, custom-fitted elastic compression stockings or sleeves are worn; those with the highest compression strength (exceeding 40 mm Hg) are required. When the leg is affected, strict bed rest with the leg elevated may aid in mobilizing the fluids.
As initial therapy, the diuretic furosemide (Lasix) is prescribed as needed to prevent the fluid overload that can result from the mo-bilization of extracellular fluid. Diuretics have also been used pal-liatively for lymphedema in conjunction with elevating the leg and wearing elastic compression stockings or sleeves. However, the use of diuretics alone has little benefit because their main action is to limit capillary filtration by decreasing the circulating blood volume. If lymphangitis or cellulitis is present, antibiotic therapy is initiated. The patient is taught to inspect the skin for evidence of infection.
Surgery is performed if the edema is severe and uncontrolled by medical therapy, if mobility is severely compromised, or if infec-tion persists. One surgical approach involves the excision of the affected subcutaneous tissue and fascia, with skin grafting to cover the defect. Another procedure involves the surgical relocation of su-perficial lymphatic vessels into the deep lymphatic system by means of a buried dermal flap to provide a conduit for lymphatic drainage.
After surgery, the management of skin grafts and flaps is the same as when these therapies are used for other conditions. Prophylactic antibiotics may be prescribed for 5 to 7 days. Constant elevation of the affected extremity and observations for complications are essential. Complications may include flap necrosis, hematoma or abscess under the flap, and cellulitis. The nurse instructs the patient or caregiver to inspect the dressing daily. Unusual drainage or any inflammation around the wound margin may suggest infection and should be reported to the physician. The patient is informed that there may be a loss of sensation in the skin graft area. The patient is also instructed to avoid the application of heating pads or exposure to sun to prevent burns or trauma to the area.