Kidney Function

In the body, blood serves as a liquid transport system. It carries important substances to all cells in the body. It also carries waste materials away from cells.

Blood is made up of fluid (plasma or serum) and contains many different kinds of cells. Red cells, which are called erythrocytes, are the most common type. The average person has over thirty-five trillion erythrocytes. If a person has anemia, they have a reduced number of red blood cells. A doctor can tell how many red blood cells a person has by doing a blood test of the hematocrit or a red blood cell count. The hematocrit tells what percent of the blood is red cells. A normal hematocrit level is between 38% and 48%, but a level of 24 to 30 is still satisfactory for a dialysis patient. The doctor may also measure the hemoglobin level. Hemoglobin is the molecule that carries oxygen in red blood cells. A normal hemoglobin level is between 12 grams and 16 grams per deciliter. A normal red blood cell count is between 4.4-5.8 million per microliter.

Purpose of Red Blood Cells
Hemoglobin in the red blood cells carries oxygern to all parts of the body. The red cells are the oxygen transport system. The body uses oxygen as a fuel or source of energy. When a person is anemic, and does not ahve enough red blood cells, parts of the body do not get enough oxygen to work properly and the person may feel exhausted and out of breath. People with anemia may feel like they have no energy. The hemoglobin in red blood cells also serves to transport carbon dioxide, a waste product from the cells or tissues throughout the body to the lungs where carbon dioxide is excreted.

Symptoms of Anemia
Along with lack of energy, other symptoms of anemia include fatigue, depression, and inability to concentrate or exercise normally. Shortness of breath, palpitations (rapid or irregular heart beat), impotence (failure to achieve adequate penile erection), dizziness, light-headedness and constantly feeling cold are also symptoms of anemia.

Can Dialysis Help with Anemia?
Normally, the kidneys remove fluids and toxins from the blood stream. For people with kidney disease, dialysis does much of this work for the kidneys. However, dialysis cannot replace erythropoietin. Nevertheless, some dialysis patients are not anemic, even without being given erythropoietin.

How can Anemia be Treated?
Dialysis patients may receive blood transfusions if they are anemic. When patients are transfused, they receive red blood cells from a blood donor. They might also receive anabolic male-type (androgenic) hormones, such as decadurabolin. These substances may help raise the hematocrit to some degree.

Now there is an effective way to treat anemia in people with kidney failure. Scientists have found a way to produce erythropoietin in a laboratory using recombinant DNA technology. This erythropoietin is called recombinant human erythropoetin, or simply “EPO”.

Blood studies are generally performed to determine if you are maintaining your diet and medication properly and also to evaluate the effectiveness of your dialysis treatment. A group of blood tests is usually done monthly as a monitoring method to keep an eye on your blood chemistries. Blood may be drawn from the blood tubing at the beginning of a dialysis treatment for laboratory studies and sometimes during and at the end of dialysis. These tests include creatinine, blood urea nitrogen and hematocrit. Other blood tests are performed to determine the levels of potassium, sodium, bicarbonate, calcium and phosphate in the bloodstream.

Why is Fluid a Problem?

Properly functioning kidneys prevent the fluid in the body from building up by removing the excess body fluid as urine. When your kidneys are not functioning, fluid may accumulate in your bloodstream. A large amount of fluid in your blood can cause high blood pressure and it also places a strain on your heart. Although fluid can also collect in your lungs, making it difficult to breathe properly, this can be controlled by bringing the body to a dry weight or a weight at which the blood pressure is normal and no swelling is present. You should achieve proper fluid balance by watching your diet and fluid intake between dialysis treatments.

Will I Experience Muscle Cramps?

Muscle cramps are most likely to occur if you are overweight due to the excess fluid in your body. A major cause of muscle cramps is the removal of a large amount of fluid during treatment. The best way to avoid muscle cramps is to limit salt and fluid intake.

Will Itching be a Problem?

You may experience some itching as a result of kidney failure (uremia), the level of phosphorus in the body or allergies to medications you may be taking. If the itching symptoms are related to uremia, your doctor may increase dialysis or prescribe medications, and, in some cases, recommend ultraviolet light treatments. Your physician adjusts the intake of phosphorus through diet and medication if the itching is related to phosphorus. Your medications may be adjusted if the itching is a result of an allergic reaction to medications.

In the past, transfusion was the only effective way to treat anemia in dialysis patients. When you receive a transfusion, you receive red blood cells from a blood donor. However, you can also be at risk of receiving an infection from the blood donor, such as hepatitis (other than Hepatitis B, which is tested for) or even AIDS (if the donor has recent infection and has not yet developed antibodies, which are the basis of the blood test done to screen out the overwhelming majority of infected donors).

Prior to the advent of human recombinant erythropoietin, anemia in these dialysis patients was treated with androgenic steroid hormones and, if necessary, transfusions of red blood cells.

Both of these treatments had important drawbacks. Androgen (male) steroids were administered by weekly injection into the muscle. Their mode of action was to stimulate cells in the bone marrow to produce more red blood cells. Unfortunately, androgens had limited effectiveness and, as a side effect, promoted the development of masculine sexual characteristics such as facial and body hair and even deepening of the voice. Blood transfusions are a more effective way of treating anemia. Their usefulness is limited by the danger of transmitting certain viral diseases, such as hepatitis. Furthermore, blood transfusions contain a large amount of iron. Some of the iron is deposited in the liver and other organs. After many units have been given, the iron may potentially cause disease of these organs.

Benefits of Treatment with Recombinant Human Erythropoietin
The most important benefit of treatment with recombinant human erythropoietin is an increase in the number of red cells in the blood. Once the number of red blood cells available to carry oxygen to all parts of the body increases, you may not require transfusions, unless you have sudden or substantial bleeding, such as from an ulcer of the stomach or intestine.

Dialysis patients with anemia who have received EPO also commonly experience improved quality of life and sense of well-being. After treatment with EPO, many patients notice an improvement in their ability to work, and their sexual performance, appetite, ability to exercise, social activity, sleep, ahir texture and skin color.