Edema (from the Greek "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid in the interstitium, which are locations beneath the skin or in one or more cavities of the body. It is clinically shown as swelling. Generally, the amount of interstitial fluid is determined by the balance of fluid homeostasis, and increased secretion of fluid into the interstitium or impaired removal of this fluid may cause edema.

Five factors can contribute to the formation of edema:

1. It may be facilitated by increased hydrostatic pressure 
2. Reduced oncotic pressure within blood vessels;
3. Increased blood vessel wall permeability as in inflammation;
4. Obstruction of fluid clearance via the lymphatic system; or,
5. Changes in the water retaining properties of the tissues themselves. Raised hydrostatic pressure often reflects retention of water and sodium by the kidney

Some of the causes of edema include:

1. Low albumin (hypoalbuminemia): Albumin and other proteins in the blood act like sponges to keep fluid in the blood vessels. Low albumin may contribute to edema, but isn't usually the sole cause.
2. Allergic reactions: Edema is a usual component of most allergic reactions. In response to the allergic exposure, the body allows nearby blood vessels to leak fluid into the affected area.
3. Obstruction of flow: If the drainage of fluid from a body part is blocked, fluid can back up. A blood clot in the deep veins of the leg can result in leg edema. A tumor blocking lymph or blood flow will cause edema in the affected area.
4. Critical illness: Burns, life-threatening infections, or other critical illnesses can cause a whole-body reaction that allows fluid to leak into tissues almost everywhere. Widespread edema throughout the body can result.
5. Edema and heart disease (congestive heart failure): When the heart weakens and pumps blood less effectively, fluid can slowly build up, creating leg edema. If fluid buildup occurs rapidly, fluid in the lungs (pulmonary edema) can develop.
6. Edema and liver disease: Severe liver disease (cirrhosis) results in an increase in fluid retention. Cirrhosis also leads to low levels of albumin and other proteins in the blood. Fluid leaks into the abdomen (called ascites), and can also produce leg edema.
7. Edema and kidney disease: A kidney condition called nephrotic syndrome can result in severe leg edema, and sometimes whole-body edema (anasarca).
8. Edema and pregnancy: Due to an increase in blood volume during pregnancy and pressure from the growing womb, mild leg edema is common during pregnancy. However, serious complications of pregnancy such as deep vein thrombosis and preeclampsia can also cause edema.
9. Cerebral edema (brain edema): Swelling in the brain can be caused by head trauma, low blood sodium (hyponatremia), high altitude, brain tumors, or an obstruction to fluid drainage (hydrocephalus). Headaches, confusion, and unconsciousness or coma can be symptoms of cerebral edema.

Diagnosis of edema:

A GP (general practitioner, primary care physician) will want to determine what the underlying cause of the edema is. The patient will be asked questions about his/her:

• Medical history.
• Current state of health.
• How long the signs and symptoms have existed.
• How permanent or intermittent the signs and symptoms are.
• Whether the patient has had edema before.

The physician will also carry out a physical exam. If there are indications that there may be an underlying medical condition causing the edema the doctor may order some tests, these may include:

• A chest X-ray
• Blood tests
• Urine tests
• Liver function tests
• Heart function tests

TABLETS:

Bumetanide 1 mg – For oral use

INDICATIONS:

BURINEX is indicated whenever diuretic therapy is required in the treatment of oedema e.g. associated with congestive heart failure, cirrhosis of the liver, renal diseases including the nephrotic syndrome. Acute pulmonary oedema, drug–induced fluid retention, and drug poisoning that can be treated by forced diuresis. Hypertension.

DOSAGE:

Orally: 1 mg daily.

In refractory cases the dose can be increased gradually till a satisfactory response has been obtained. Rarely will it be necessary to exceed a dose of 4 mg daily. The 5 mg tablet is for use in resistant oedema due to renal insuffi-ciency and where higher doses are required. In high dose therapy consideration should be given to a twice daily dosing.

Children: The dose is calculated on the basis of 0.03–0.06 mg/kg daily.

Elderly: Adjust dosage according to response; a dose of 0.5 mg daily may be sufficient in some elderly patients.