Introduction to Renal Nutrition

When the kidneys fail:

• The food that we eat is broken down and used as building blocks for maintenance and growth by the body. The excess products must be discarded, and this is the job of the kidney. When kidneys fail, they cannot eliminate waste products, and these wastes accumulate and poison the body. This leads to a condition known as uremia.
• The waste products that accumulate are harmful to the body.
• The kidney also has the job of regulating fluids. In kidney failure, fluids and a mineral known as sodium (salt) can accumulate, leading to high blood pressure and heart failure.
• Acids are minerals that can lower the body pH if not elimated or buffered. The kidney plays a key role in this process, but in kidney failure, it loses its ability to do so, leading to acidosis.
• The body is made up of cells.The balance of potassium between body cells is very important to cellular function. Potassium cannot be elimated when the kidneys fail, and accumulates. It can harm the body.
• Phosphorus is a mineral that is eliminated by the kidney. When it accumulated, it accumulated in the cells that surround the blood vessels. This causes these cells to change into bone-type cells that harden and damage the blood vessels. This interferes with blood flow, and also damages the heart.
• They fail to produce a hormone that fights anemia (low red blood cells)
• Vitamin D cannot be activated, interfering with bone and calcium metabolism, and ultimately leads to damaged blood vessels.
• The wastes that can harm the body come from foods containing protein, acids, sodium, potassium, phosphorus, and fluid.

Chronic kidney disease is divided into five stages. These stages are classified based upon the glomerular filtration rate (GFR), a measure of kidney function. The symptoms of kidney disease start to begin in Stage 3, when the GFR falls below 60 cc per minute. In this stage, the anemia, acidosis and bone disease begin. By Stage 4, when the GFR is less than 30 cc per minute, the appetite may start decreasing. It is in the fifth stage, when the GFR is less than 15 cc per minute, that the signs and symptoms of kidney disease worsen to the point that renal replacement therapy - dialysis or a kidney transplant - become necesessary. When your kidneys do not function well, you may have uncomfortable side effects such as a loss of energy, fatigue, irritability, trouble sleeping.

Progressive kidney disease kidney diseases causes a loss of appetite. You may feel ill. As the disease progresses, one can feel nauseated, confused, delirious, and even slip into a coma. Since dialysis became readily available in the 1970s, the late stages of kidney failure have rarely been seen, but patients who miss dialysis treatments frequently often have some of the early signs of uremia. The loss of appetite in the stages of kidney disease that precede dialysis may lead to malnutrition. nausea, and high blood pressure. Dialysis removes waste products from the body and helps decrease these side effects. In hemodialysis, blood is removed from the body and passes through a plastic filter. Here it comes in contact with a solution of electrolytes (charged atoms needed by the body, but dangerous in excess). The blood that has been "cleansed" is then pumped back to the body. The dialysis and filtration process that is performed here removes, wastes and fluid while replenishing back the necessary electrolytes.

In peritoneal dialysis, a plastic tube is surgically placed in the peritoneal space of the abdomen - the area that surrounds the intestines - and fluid is allowed to dwell in the abdomen and then drain out. This fluid is balanced, and thus removes the excess dangerous molecules and wastes while replenishing those elements that the body needs. Despites its ability to help sustain life and well being, dialysis is not as efficient as normal kidneys. For instance, it cannot remove phosphorus. Furthermore, while the kidneys are working steadily for twenty-four hours a day, standard incenter hemodialysis is generally performed three days a week, and there a waste products, as well as the acids, potassium, and sodium that build up between each treatment. For these reasons, dialysis patients need to watch their fluids, keep their blood pressure and serum phosphorus under control, and follow a special diet.

The renal dietitian is specially trained to work with people with kidney disease. The dietitian works with you and your family to assure that prior to requiring dialysis, you receive a diet that will meet your needs while acocomodating your food preferences and lifestyle. As disease progresses, and dialysis becomes necessary, the dietitian will change your diet. Your diet plan may be modified periodically as your condition or type of dialysis changes. Your dietitian will keep you informed of any changes needed in your diet.