How important is the balance of potassium, sodium, and phosphorus in the diet of the hemodialysis patients?
The lоw intake of potassium, sodium, and phosphorus is crucial when the case involves feeding patients on hemodialysis.
Potassium
Potassium is involved in the water balance maintaining and in the transmission of nerve impulses and muscles contractions and regulates the blood pressure.
High plasma potassium is a life-threating case of emergency and is an indicator that the patient has made a mistake with his/her diet. Such a state of health is called hyperkalemia and is distinguished by muscle weakness, paralytic symptoms and irregular heart beat, In patients with anuria (complete absence of diuresis) the potassium intake is limited up to 1.5 – 2.0 gr. per day.
Dietary recommendations: the intake of rich in K food is limited – stone fruits, beans, lentils, olives, nuts, vegetable juices, dietary salt, dried fruits. Potatoes and the other vegetables lose most of the potassium when they are pre-cut and soaked in water for 3 hours as well as when they are cooked for 30 minutes. When using canned fruits and vegetables the liquid must be removed beforehand. Fruit juices, dried fruits, and nuts must be avoided.
Sodium
It is crucial to minimize sodium intake and to avoid food additives and fast foods. The use of salt causes fluid retention in the body and is a reason for high blood pressure, cardiac hypertrophy and eventually increases cardio-vascular mortality. Water and potassium control for patients on dialysis is important for the quality of the dialysis treatment and for their survival.
Dietary recommendations: to avoid rich in salt food – canned, marinated, salty and smoked products.
Phosphorus
Since phosphorus can not be fully extracted through dialysis, it is accumulated, thus damaging the bone structure and making bones fragile. The product of potassium and phosphorus values is called the potassium-phosphorus product and its levels should not overcome 4. Otherwise, it is subcutaneously accumulated and causes unpleasant itching.
Dietary recommendation: Foods high in phosphorus must be limited. Limiting the intake of phosphorus may also be done by decreasing the intake of proteins in food. However, this may cause malnutrition of the patient, which is highly undesirable. An efficient way of decreasing the serum phosphorus is the intake of calcium tablets while eating, since at that time the potassium intake is highest and its binding is most efficient.
This mineral may reach high levels in the blood and cause complications such as weak bones, heart problems, joint pain, and skin ulcers.