Kidney Disease : Part 3

by Food and Drug Administration (FDA)

(Page 3 of 3)

The kind and degree of dietary restriction depends on the stage of a patient's disease. In general, patients are advised to limit protein intake and be sure that a certain portion of it is high quality protein found in foods such as eggs, meat, fish, poultry, milk, and cheese. Because of its role in high blood pressure, sodium is sharply limited in the diets of most kidney disease patients. Calcium intake is also limited, requiring the patient to limit consumption of milk and milk products. Patients on dialysis may have to restrict potassium and water, but that?s not usually necessary in the early stages of kidney disease.

Several kinds of medication can help manage the symptoms of kidney disease, though no specific drug is known to be effective against the fundamental cause of nephritis. Steroidal anti-inflammatory agents, diuretics, and antihypertensive drugs are useful in retarding kidney damage and lowering blood pressure.

But eventually the disease will progress to a point at which the kidneys can no longer cleanse the blood adequately. At that stage, life-saving measures are needed.

Role of Dialysis

Dialysis is a procedure that artificially replaces some of the kidney's normal function, enough at least to allow most patients whose kidneys have failed to live relatively normal lives. There are two types hemodialysis and peritoneal dialysis. In hemodialysis, the patient's bloodstream is diverted to an external machine that continuously filters the blood, corrects its chemistry, and returns it to the body.

Usually, hemodialysis patients are treated about three times a week. The procedure can be carried out in a hospital, a dialysis center, or at home. Home dialysis can be more convenient for the patient, but it requires that the patient or care-giver be thoroughly familiar with the dialysis procedure and equipment and the critical importance of measures to prevent contamination of the blood supply. At home or in a health-care facility, each dialysis treatment lasts about five hours.

In continuous ambulatory peritoneal dialysis the patient's blood is not shunted outside the body. Instead, a catheter placed in the patient's abdomen allows the abdominal space to be slowly filled with a solution the dialysate used to clean and re-balance the chemistry of blood flowing through vessels in the abdomen. After about four or five hours, the dialysate is allowed to drain through the catheter and a fresh supply is introduced. The procedure is repeated several times a day while the patient goes about normal activities.

Cycling peritoneal dialysis is basically identical. It, however, requires an external machine and is usually done for about an hour and a half at night while the patient sleeps. Intermittent peritoneal dialysis is a hospital procedure that takes 10 to 12 hours. The oldest form of dialysis, it is often used in emergencies or as the first dialysis procedure following total kidney failure.

Help for Patients with Failed Kidneys

Patients suffering from chronic kidney failure frequently have severe anemia because the kidneys cannot produce enough erythropoietin, a hormone that stimulates red blood cell production. As a result, they need frequent transfusions, which raises the risk of infection from contaminated blood and eventually causes a dangerous build-up of iron. In June 1988, FDA approved Epogen, genetically engineered erythropoietin that can be administered to patients to boost their red cell production, thereby sharply lowering the need for transfusion.

With present incomplete knowledge of the cause and cure of kidney disease, transplantation offers an alternative to repeated dialysis for patients who have end-stage kidney failure. Some 7,000 Americans a year receive a kidney transplant, but about 60 percent of them need long-term treatment to prevent their own immune systems from attempting to reject the transplanted kidney. The anti-rejection drug Sandimmune (cyclosporine) is widely used in these cases, as are steroids such as prednisone. In June 1988, FDA approved a new agent to reverse acute kidney transplant rejection, Orthoclone OKT3 (muromonab-CD3). The drug blocks the action of T-cells, the white blood cells that are responsible for the body's rejection of foreign tissue.

The treatment of kidney failure is one of the most successful and beneficial applications of modern medical science. Although there is still a long road ahead to effective prevention or cure, current medical developments give those with a diagnosis of kidney disease strong reasons to be optimistic about treatment.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.