Chronic Renal Failure

Chronic renal failure (CRF) is a slow progressive loss of renal function over a period of months or years and defined as an abnormally low glomerular filtration rate, which is usually determined indirectly by the creatinine level in the blood serum.

CRF results in uremia (urea in blood). It is a gradual and progressive loss of the ability of the kidneys to excrete wastes, concentrate urine, and conserve electrolytes.

CRF that leads to severe illness and requires some form of renal replacement therapy (such as dialysis) is called end-stage renal disease (ESRD).

The causes of CRF are glomerulonephritis, metabolic disease with renal involvement such as diabetes mellitus, especially Diabetes Type 1 (IDDM), hypertension, exposure to toxic substances, kidney stones and infections, renal vascular diseases, renal tubular diseases, chronic pyelonephritis, and congenital abnormalities of both kidneys.

CRF results in accumulation of fluids and waste products which can lead to many clinical signs and complications such as decreased ability of the kidneys to maintain body water balance, concentrate solutes in body fluid and electrolyte and acid-base balance.

Feeding is a challenge in CRF as anoerexia and taste changes reduce food intake. The main focus of dietary management is on protein, sodium, potassium, phosphate, water and adequate non-protein calories.

Nutrients	Note
Calories	30-40 Kcal/Kg/day for adults and 100-150 kcal/kg/day for children.
Carbohydrates	300-400g/day to avoid endogenous protein catabolism, gluconeogenesis and subsequently uremia.
Proteins	0.5 g/kg/day, with 60-70% as high Biological Value Protein. To reduce nitrogen load, a mixture of essential amino acids is recommended.
Sodium	500-2000mg/day. Additional sodium in case of weight loss and decreasing urine volume and restriction of sodium in case of oedema and hypertension.
Potassium	Intake must be kept at 1500mg/day and in case of significant losses, potassium supplements should be given.
Calcium and Phosphorus	Calcium supplementation – 1-2 g/day and phosphate to be restricted to 800-1200 mg/day.
Vitamin	Multivitamin supplements, especially vitamin D3.
Fluids	Intake is dependent on urine output and water balance.

Also read about other Diseases of the Kidney in the Diet Corner column.

Post by Faiz Lahori