Nutrition in Hemodialysis: Its Measurement and Meaning (original) (raw)

Nutrition is one of the essential elements of the dialysis prescription (1). In contrast to the dialysis itself, nutrition can only be guided by the physician and dietician; it is ultimately controlled by the patient either voluntarily or involuntarily by disease. It mirrors the success of dialysis but can be an independent risk factor for morbidity and mortality when controlled by another disease (e.g., tuberculosis). Hemodialysis, because of its intermittent nature, offers an opportunity for measuring an important aspect of nutrition, the patient's protein intake, from simple measurements of blood urea nitrogen (BUN). Protein intake is estimated from the patient's protein catabolic rate (PCR), calculated from the change in BUN between dialyses. The other elements of the prescription that are easily measured in hemodialyzed patients are the midweek predialysis BUN and Kt/V (where K is the urea clearance of the dialyzer, t is time on dialysis, and V is the volume of urea distribution). KzIV reflects the amount of dialysis prescribed or delivered during each treatment. BUN only expresses the ratio of dietary protein intake/amount of dialysis treatment.