Nephrology

536 Nutrition In Acute Renal Failure

  • Nutrition In Acute Renal Failure

    Nutritional management of a child with acute renal failure requires consideration of many nutrients; most particularly energy, protein, sodium and potassium.  The aim of nutritional management is to: provide sufficient nutrients to limit the catabolic response, and to hasten renal recovery within the restrictions set by the limited renal capacity.  Enteral or parenteral nutrition may be necessary to ensure appropriate nutrient intakes.

    Energy

    If energy intake is inadequate then any nitrogen source (endogenous or exogenous) will be used as a fuel thereby contributing to the uraemia.

    It is important to provide the maximum energy intakes possible within fluid restrictions.  Estimated energy requirements should be based on at least the RDI's for normal children of the same age with allowance of 25% increase to avoid catabolism.

    For children and infants anorexia is often a feature of ARF and adequate energy intakes can be difficult to achieve.  Energy intakes can be improved by supplementing foods with carbohydrate (Polyjoule) or fats (eg Calogen).

    Protein 

    A protein restriction may be required to control blood urea levels. Children will rarely consume excessive quantities of protein because of anorexia.  If enteral feeding is commenced protein may need to be restricted.  Requirements need to be tailored for each individual and will depend on age, weight, height, and dialysis therapy.

     Protein g/kg/day   
      Conservative Management Peritoneal Dialysis Haemodialysis
    0-6 months 1.8 2.2 - 3.0 2.2
    6-12 months 1.0 - 1.5 2.0 - 3.0 2.0
    1 - 3 years 1.0 - 1.5 2.0 - 3.0 2.0
    Children and Adolescents 1 1.0 - 1.5 1.0 - 1.5

    Sodium

    The degree of salt restriction depends on blood pressure, oedema and urine output

    Usually a 'no added salt' diet is adequate

    Fluid

    The volume of fluid prescribed during conservative treatment is based on urine output and insensible losses plus other extraordinary losses eg fever.  Maximum nutrient intake should be provided within the fluid allowance.  Accurate recording of fluid intakes must be made including all oral, nasogastric or intravenous fluid as well as fluids from foods such as jelly, yoghurt etc

    Phosphorus

    Elevated levels of phosphorus indicate a need for dietary restriction of phosphorus.  Phosphate binders (eg. Calcium carbonate) may also be required to achieve acceptable levels

    Potassium

    Dietary potassium restriction is indicated by elevated serum potassium levels.  Rich sources of potassium such as citrus fruits, tomato paste, chocolates and potato crisps should be avoided

    When the acute episode is over and dialysis, if instigated, is suspended dietary restrictions can be gradually relaxed.

    Parenteral Nutrition in ARF

    This will be essential if enteral nutrition is not tolerated.  Standard solutions may not be suitable because of electrolyte composition and fluid restrictions.

    A concentrated amino acid source may be required with intakes of up to 2g amino acids/kg/d if dialysis is taking place.  Essential amino acids should not be the sole nitrogen source as renal failure alters the metabolic response eg. histidine and arginine become essential in uraemic individuals.  It is unclear whether uraemic and catabolic infants can adequately synthesize non essential amino acids from essential amino acids.  Dialysis whether haemo or peritoneal will also increase requirements for protein and amino acids

    Using a concentrated amino acid source means greater volumes of energy providing solutions, dextrose and lipid, can be given. 

    Both water and fat soluble vitamins and trace elements should be routinely added.  Electrolytes should be added according to blood biochemistry

    References

    J.E. Coleman and A.R. Watson.  Nutritional Support for the child with acute renal failure. Jnl. Human Nutrition and Dietetics (1992) 5, 99-105

    D. Gillit, J. Stover & N. Spinozzi (Ed) A Clinical Guide to Nutrition Care in End Stage Renal Failure, 1987, American Dietetic Association

    W.E. Grupe.  Nutritional Considerations in the Management of Infants and Children with Renal Disease In Text book of Gastroenterology and Nutrition in Infancy, 2nd Ed, Raven Press, 1989