End-Stage Renal Disease
End-stage renal disease (ESRD) refers to the condition, where the kidneys are functioning minimally or not at all. Dialysis helps keep the body in balance by removing waste products and excess water, maintaining the proper levels of certain chemicals (potassium, sodium, and bicarbonate), and helping to control the blood pressure. Dialysis prolongs life but some patients may choose not to have dialysis and instead follow conservative care. MNT in ESRD focuses on protein, phosphorus, potassium, sodium, and fluid. The diet is individualized based on laboratory levels, the patient’s nutrition status and lifestyle, and the modality of dialysis. With patients who choose conservative care rather than dialysis, the focus is on managing the symptoms of uremia. A kidney transplant center will assess if a patient is a suitable candidate for a kidney transplant.
In hemodialysis, the choice is in-center (HD), home hemodialysis (HHD), or nocturnal home dialysis (NHD). The diet for HD and HHD are very similar whereas patients on NHD require fewer restrictions. The time needed for dialysis depends on residual kidney function, how much fluid weight has been gained, and body mass index (BMI). The greatest challenge for nutrition therapy is related to fluid, potassium, and phosphorus. The diet is individualized based on serum levels of potassium and phosphorus, and also weight gain between dialysis sessions. The albumin level, a marker of inflammation, and protein catabolic rate (PCR) are also monitored to ensure that patients have adequate protein intake and status. The focus of MNT in hemodialysis is to ensure the patient is receiving adequate nutrition while maintaining the balance of the body’s minerals (potassium, phosphorus, and calcium) and fluid levels. When patients are unable to meet their protein needs, the RD/RDN will recommend nutrition supplements or intra-dialytic amino acid solutions to improve the nutrition status.
There are two choices with peritoneal dialysis (PD), namely, continuous ambulatory peritoneal dialysis (CAPD) or continuous cyclic peritoneal dialysis (CCPD) also known as automated peritoneal dialysis (APD). The basic treatment is the same for each with exchanges of dialysate (usually a dextrose or icodextran solution). CAPD is “continuous,” machine-free, and done several times during the day with exchanges done using gravity to drain and then fill the peritoneum in a sanitary environment. With CCPD/APD, a machine (cycler) delivers and then drains the dialysate. The treatment is usually done at night while the patient is sleeping. Patients on peritoneal dialysis require more protein and potassium in their diets. The dextrose used in the dialysate has calories which may contribute to weight gain and thereby aggravate existing diabetes and lipid disorders. If a patient is not able to meet their protein needs, nutrition supplements or dialysate with amino acids may be recommended.
For all types of treatment for ESRD (HD, PD, transplant, or conservative care) the RD/RDN experienced in kidney disease recommends changes to medications so as to manage disorders in serum levels of minerals (such as potassium, phosphorus, and calcium) or iPTH and vitamin D levels. The assessment of nutritional risk factors will allow RD/RDNs to provide customized MNT. The RD/ RDN will help patients with nutrition choices to optimize their nutrition status, fluid balance, and assist the patient with their nutritional goals.