Viele Menschen, die dialysepflichtig sind, haben wenig oder keine Urinausscheidung
und können ihren Volumenstatus nicht ohne die Dialyse regulieren. Ebenso fehlt die
Ausscheidung von Kalium und Phosphat über die Nieren. Beide Elektrolyte im Normbereich
zu halten, ist eine Herausforderung. Die Ernährung bei Dialyse ist komplex und Mangelernährung
häufig. In diesem Artikel werden die Hintergründe sowie aktuelle Studien vorgestellt.
Abstract
Dietary recommendations for patients on dialysis are changing as our understanding
of enteral microbiotal metabolism and bioavailability of nutrients from food improves.
A diet low in phosphate and potassium is recommended for patients on hemodialysis.
However, the absolute content does not reflect bioavailability: How much phosphate
or potassium is taken up depends on food source (plant vs. animal) and to which grade
it is processed. While both are nearly 100% bioavailable from industrially processed
foods (additives such as dipotassium-phosphate and other salts), a much lower proportion
is taken up from unprocessed plant foods high in fibre (ca. 20–40%). The DIET-HD study
showed no significant association between dietary potassium and serum potassium in
> 8 000 dialysis patients; and those with the highest low-processed, fresh plant-food
consumption have the best survival. Dietary fibre improves colon transit time and
thereby lessens symptoms of constipation. A diet low in sodium improves blood pressure
and volume management in dialysis patients. The energy and protein requirements on
dialysis are high: 25–35 kcal and 1–1,2 g protein per kg body weight per day (in relation
to “ideal” body weight, if patient is overweight). Protein energy wasting is associated
with higher stages of kidney disease, and malnutrition is associated with worse survival
on dialysis. Nutritional status should be assessed on a regular basis using validated
scores, and malnutrition should be addressed and treated.
Schlüsselwörter
Ernährung - Dialyse - Ballaststoffe - Mangelernährung - Phosphat
Keywords
Nutrition - dialysis - dietary fibre - malnutrition - phosphate
