Edema! Includes Causes---thanks Pam

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Edema

Definition

Edema is a condition of abnormally large fluid volume in the circulatory

system or in tissues between the body's cells (interstitial spaces).

Description

Normally the body maintains a balance of fluid in tissues by ensuring that

the same of amount of water entering the body also leaves it. The

circulatory system transports fluid within the body via its network of

blood vessels.

The fluid, which contains oxygen and nutrients needed by the cells, moves

from the walls of the blood vessels into the body's tissues. After its

nutrients are used up, fluid moves back into the blood vessels and returns

to the heart.

The lymphatic system (a network of channels in the body that carry lymph,

a colorless fluid containing white blood cells to fight infection) also

absorbs and transports this fluid. In edema, either too much fluid moves

from the blood vessels into the tissues, or not enough fluid moves from

the tissues back into the blood vessels. This fluid imbalance can cause

mild to severe swelling in one or more parts of the body.

Causes and symptoms

Many ordinary factors can upset the balance of fluid in the body to cause

edema, including:

Immobility. The leg muscles normally contract and compress blood vessels

to promote blood flow with walking or running. When these muscles are not

used, blood can collect in the veins, making it difficult for fluid to

move from tissues back into the vessels.

Heat. Warm temperatures cause the blood vessels to expand, making it

easier for fluid to cross into surrounding tissues. High humidity also

aggravates this situation.

Medications. Certain drugs, such as steroids, hormone replacements,

nonsteroidal anti-inflammatory drugs (NSAIDs), and some blood pressure

medications may affect how fast fluid leaves blood vessels.

Intake of salty foods. The body needs a constant concentration of salt in

its tissues. When excess salt is taken in, the body dilutes it by

retaining fluid.

Menstruation and pregnancy. The changing levels of hormones affect the

rate at which fluid enters and leaves the tissues.

Some medical conditions may also cause edema, including:

Heart failure. When the heart is unable to maintain adequate blood flow

throughout the circulatory system, the excess fluid pressure within the

blood vessels can cause shifts into the interstitial spaces. Left-sided

heart failure can cause pulmonary edema, as fluid shifts into the lungs.

The patient may develop rapid, shallow respirations, shortness of breath,

and a cough. Right-sided heart failure can cause pitting edema, a swelling

in the tissue under the skin of the lower legs and feet. Pressing this

tissue with a finger tip leads to a noticeable momentary indentation.

Kidney disease. The decrease in sodium and water excretion can result in

fluid retention and overload.

Thyroid or liver disease. These conditions can change the concentration of

protein in the blood, affecting fluid movement in and out of the tissues.

In advanced liver disease, the liver is enlarged and fluid may build-up in

the abdomen.

Malnutrition: Protein levels are decreased in the blood, and in an effort

to maintain a balance of concentrations, fluid shifts out of the vessels

and causes edema in tissue spaces.

Some conditions that may cause swelling in just one leg include:

Blood clots. Clots can cause pooling of fluid and may be accompanied by

discoloration and pain. In some instances, clots may cause no pain.

Weakened veins. Varicose veins, or veins whose walls or valves are weak,

can allow blood to pool in the legs. This is a common condition.

Infection and inflammation. Infection in leg tissues can cause

inflammation and increasing blood flow to the area. Inflammatory diseases,

such as gout or arthritis, can also result in swelling.

Lymphedema. Blocked lymph channels may be caused by infection, scar

tissue, or hereditary conditions. Lymph that can't drain properly results

in edema. Lymphedema may also occur after cancer treatments, when the

lymph system is impaired by surgery, radiation, or chemotherapy.

Tumor. Abnormal masses can compress leg vessels and lymph channels,

affecting the rate of fluid movement.

Symptoms vary depending on the cause of edema. In general, weight gain,

puffy eyelids, and swelling of the legs may occur as a result of excess

fluid volume. Pulse rate and blood pressure may be elevated. Hand and neck

veins may be observed as fuller.

Diagnosis

Edema is a sign of an underlying problem, rather than a disease unto

itself. A diagnostic explanation should be sought. Patient history and

presenting symptoms, along with laboratory blood studies, if indicated,

assist the health professional in determining the cause of the edema.

Treatment

Treatment of edema is based on the cause. Simple steps to lessen fluid

build-up may include:

Reducing sodium intake. A high sodium level causes or aggravates fluid

retention.

Maintaining proper weight. Being overweight slows body fluid circulation

and puts extra pressure on the veins.

Exercise. Regular exercise stimulates circulation.

Elevation of the legs. Placing the legs at least 12 in (30.5 cm) above the

level of the heart for 10-15 minutes, three to four times a day,

stimulates excess fluid re-entry into the circulatory system.

Use of support stocking. Elastic stockings, available at most medical

supply or drug stores, will compress the leg vessels, promoting

circulation and decreasing pooling of fluid due to gravity.

Massage. Massaging the body part can help to stimulate the release of

excess fluids, but should be avoided if the patient has blood clots in the

veins.

Travel breaks. Sitting for long periods will increase swelling in the feet

and ankles. Standing and/or walking at least every hour or two will help

stimulate blood flow.

The three " Ds " --diuretics, digitalis, and diet--are frequently prescribed

for medical conditions that result in excess fluid volume. Diuretics are

medications that promote urination of sodium and water. Digoxin is a

digitalis preparation that is sometimes needed to decrease heart rate and

increase the strength of the heart's contractions. Dietary recommendations

include less sodium in order to decrease fluid retention. Consideration of

adequate protein intake is also made.

For patients with lymphedema, a combination of therapies may prove

effective. Combined decongestive therapy includes the use of manual lymph

drainage (MLD), compression bandaging, garments and pumps, and physical

therapy. MLD involves the use of light massage of the subcutaneous tissue

where the lymph vessels predominate. Massage begins in an area of the body

trunk where there is normal lymph function and proceeds to areas of

lymphatic insufficiency, in an effort to stimulate new drainage tract

development. (MLD should not be used for patients with active cancer, deep

vein clots, congestive heart failure, or cellulitis.) MLD sessions are

followed by application of compression garments or pumps. Physical therapy

is aimed at strengthening the affected limb and increasing joint mobility.

Alternative treatment

Dietary changes, in addition to cutting back the amount of sodium eaten,

may also help reduce edema. Foods that worsen edema, such as alcohol,

caffeine, sugar, dairy products, soy sauce, animal protein, chocolate,

olives, and pickles, should be avoided. Diuretic herbs can also help

relieve edema. One of the best herbs for this purpose is dandelion

(Taraxacum mongolicum), since, in addition to its diuretic action, it is a

rich source of potassium. (Diuretics flush potassium from the body and it

must be replaced to avoid potassium deficiency.) Hydrotherapy using daily

contrast applications of hot and cold (either compresses or immersion) may

also be helpful.

Digitalis

A naturally occuring compound used in the preparation of the medication,

digoxin, prescribed to increase the heart rate and strengthen the force of

the heart's contractions.

Diuretics

Medications used in the treatment of fluid overload, to promote excretion

of sodium and water.

Interstitial spaces

Areas of the body occuring outside the vessels or organs, between the

cells.

Pitting edema

A swelling in the tissue under the skin, resulting from fluid

accumulation, that is measured by the depth of indentation made by finger

pressure over a boney prominence.

For Your Information

Books

Monahan, Frances D., and nne Neighbors. Medical-Surgical Nursing:

Foundation for Clinical Practice. 2nd ed. Philadelphia: W. B. Saunders

Co., 1998.

Organizations

Lymphedema and Wound Care Clinic of Austin. 5750 Balcones Dr., Ste. 110,

Austin, TX 78731. (512) 453-1930.

The Essay Author is Kathleen D. RN.