Nutrition in Renal Failure
Discuss enteral nutrition in acute renal failure?
- Nutritional status is one of the main factors determining outcome in ARF patients.
- ARF, especially in ICU seldom occurs as isolated organ failure but usually in the setting of MODS.
- Standard formulae are adequate for most patients. Disease specific formulae for CRF may be justified in pts exclusively on EN or in hypercatabolic ICU patients
- Nutritional requirements (ESPEN 2006)
- Non protein Energy- 20-30Kcal/kg/day (adjust for underweight or obese)
- Carbohydrates 3-5 g/kg/day (max 7)
- Fat- 0.8-1.2 (max 1.5)g/kg/day
- Protein-
- Conservative treatment- 0.6-0.8 (max 1) g/kg/day
- Extracorporeal RRT- 1-1.5
- RRT, hypercatabolic- upto 1.7 max
- Acutely ill patients with CRF on HD should be treated as ARF.
Discuss parenteral nutrition in acute renal failure?
- Energy and macronutrient requirements as above
- Loss of protein (0.2gm/kg/day) occurs in the pts undergoing dialysis.
- The enhanced requirements of water soluble vitamins induced by extracorporeal treatment should be met by supplementing multivitamin products. Experimental ARF is associated with an increase in plasma retinol. Although retinol intoxication has not been reported in ARF patients, signs of vitamin A toxicity should be carefully sought during supplementation. Similarly Vitamin C supplementation should not exceed 30-50mg/day, because inappropriate supplementation may result in secondary oxalosis. Selenium and thiamine levels should be monitored as depletion may occur despite supplementation.
- Restriction of electrolytes (Na, K, PO4 etc) is usually unnecessary on RRT.
- Standard formulae are adequate for the majority of patients. However,
- requirements can differ and have to be assessed individually. When there are
- electrolyte derangements, three-in-one formulae without electrolytes or customized formulae can be advantageous.
Discuss nutrition in chronic renal failure (stage III to V, treated conservatively)?
- Nutritional requirements
- Calorie intake of 35Kcal/kg/day for stable CRF patients in the range of ideal body weight +/- 10% (adjust for underweight or obese)
- Protein requirements 0.55-0.6 g/kg/day (2/3 high biological value-HBV)
- Minerals (just a guide)
- Phosphate-600-1000mg/day
- K-1500-2000mg/day
- Na- 1.8-2.5g/day
- Standard formulae can be used for short-term EN (< 5 days) but for EN for more than 5 days, disease-specific formulae (protein-restricted with reduced electrolyte content) should be used.
Discuss parenteral nutrition in chronic renal failure (stage III to V, treated conservatively)?
- Energy and minerals requirements as above
- Metabolic acidosis in uraemia is an important factor for the activation of protein catabolism. Alkalinization therapy is thus standard in the treatment of CKD patients.
- Loss of protein due to proteinuria exceeding 1 g/d should lead to compensatory additions to daily protein intake such as by the calculation of protein/AA intake needed based on ideal body weight (kg x 0.6 – 0.8 x proteinuria).
- The nutritional requirements of acutely ill CKD patients are dealt with as in ARF
- Standard PN mixtures should be used if PN is indicated. In patients receiving PN without any enteral supply, vitamins and trace elements should also be administered intravenously. If the patient needs PN for a period exceeding two weeks, accumulation of vitamin A and trace elements should be considered
Discuss nutrition in chronic renal failure (on maintenance HD)?
- Nutritional requirements
- HD or CAPD- 35 Kcal/kg/day (for CAPD in pts <60- 30 Kcal/kg/day)
- Protein intake-
- HD- 1.2-1.4 (50% HBV)
- CAPD- 1.2-1.5 (50% HBV)
- Minerals (guide only)
- Phosphate-800-1000mg/day
- K-2000-2500mg/day
- Na- 1.8-2.5g/day
- Fluid- 1000+urine volume
- Due to dialysis-induced losses, water-soluble vitamins need to be supplied: folic acid (1mg/ day), pyridoxine (10–20 mg/day) and vitamin C (30–60mg /day). Vitamin D should be given according to serum calcium, phosphorus and parathyroid hormone levels.
- Thiamine should also be supplemented with a daily oral dose of 1-5 mg. Vitamin E may also be prescribed to patients at high cardiovascular risk at a daily dose of 800 IU of alpha-tocopherol. Routine haemodialysis does not induce significant trace-element losses. However, in depleted patients zinc (15 mg/day) and selenium (50–70mg/day) supplementation may be useful.
- Dialysis specific formulae should be used (high protein content of HBV, reduced electrolytes with high energy concentration)
- Due to an increased incidence of peritonitis, PEG/PEJ is contraindicated in adult CAPD patients but is standard in children
- Dialysis initially leads to improvement in nutritional indices. However, after this initial improvement, the time on dialysis becomes directly associated with a significant decline in all measured nutritional parameters because dialysis procedure is itself a catabolic event.
Discuss parenteral nutrition in chronic renal failure (on maintenance HD)?
- In acutely ill HD patients the requirements are the same as in ARF patients.
- Energy and macronutrients as above
- Phosphorus intake should be limited to 10-15 mg/kg/day. As phosphorus and protein are combined in nutrients with a ratio of 10-13 mg pho
- Conservative treatment- 0.6-0.8 (max 1) g/kg/day
- Extracorporeal RRT- 1-1.5
- RRT, hypercatabolic- upto 1.7 max
- sphorus/g protein, most HD patients who have an adequate protein intake will need phosphate binders to prevent an increase in serum phosphorus.
- Severe malnutrition is as defined as low BMI (<20), body weight loss more than 10% over 6 months, serum albumin less than 35 g/l and serum transthyretin less than 300 mg/l.
- Severe malnutrition plus spontaneous intakes less than 20 kcal/kg/day or in stress conditions: both ONS and IDPN are generally unable to provide satisfactory nutritional supply and are not recommended; daily nutritional support is necessary and EN should be preferred to PN.
- In patients exhibiting severe malnutrition, with spontaneous intakes more than 20 kcal/day: dietary counseling and ONS should be prescribed; IDPN is indicated in patients unable to comply with ONS; EN can be necessary when ONS or IDPN fail to improve nutritional status.
- IDPN- Intradialytic PN (IDPN) is a cyclic PN given (usually) three times weekly through the venous line of the dialysis circuit. The following technical rules have been proposed in order to ensure optimal tolerance:
- IDPN should be infused at constant rate during a typical 4-hour dialysis session;
- IDPN delivery should be progressively increased from 8 ml/kg/IDPN during the first week, to a maximum of 16 ml/kg/IDPN without exceeding 1000 ml/HD
- IDPN should be associated with controlled ultrafiltration, volume for volume;
- 75 mmol Na should be added per liter of IDPN solution in order to compensate Na losses due to ultrafiltration.
- IDPN typically provides 800-1200 kcal three times weekly, in the form of glucose and fat emulsion and 30 to 60 g of protein. Standard amino acid solutions can be used for IDPN.
- Recommended longitudinal monitoring of nutritional status in maintenance dialysis patients: dietary interviews every 6 months; body mass index monthly; serum albumin and transthyretin, anthropometrics every 1-3 months as needed according to nutritional status.
- Alternative treatments for protein-energy wasting in dialysis may be needed when nutritional support is insufficient. The administration of nandrolone decanoate has been demonstrated to increase muscle mass. Exercise combined with IDPN, as compared with IDPN alone, has been shown to promote net muscle protein accretion. These data argue in favor of a multimodal treatment of malnutrition in dialysis, combining nutritional support, exercise and anabolic agents.
Discuss parenteral nutrition in CAPD?
- Energy requirements as above
- Therapy-associated losses of proteins during CAPD are higher than in HD. Protein losses are approximately 10 g/day and increases in peritonitis. Because peritoneal solutions with a high glucose content are used as standard in CAPD, this method is associated with a glucose uptake of 100 to 200 g/d which is further
- increased during peritonitis. Due to the increased glucose load, body weight may
- even increase in CAPD patients. The high glucose load is also responsible for
- induction or aggravation of diabetes, hypertriglyceridaemia and increased LDL and VLDL cholesterol.
- In patients exhibiting severe malnutrition, with spontaneous intakes more than 20 kcal/day: dietary counselling and ONS should be prescribed; IPPN may be considered in patients unable to comply with ONS; EN can be necessary when ONS are unable to improve nutritional status.
- In patients exhibiting severe malnutrition, with spontaneous intakes less than 20 kcal/day, or in stress conditions: daily nutritional support is necessary and EN should be preferred to PN; central venous PN is indicated when EN is impossible or insufficient (e.g. severe encapsulating peritonitis)
- The special form of PN unique to CAPD patients is Intraperitoneal Parenteral Nutrition (IPPN). IPPN is shown to improve nitrogen balance and nutritional parameters. IPPN mainly consists of the intraperitoneal administration of 1.1% amino acid-based solution. IPPN can be associated with hypokalaemia, hypophosphataemia and mild acidosis. So close monitoring during this treatment is needed
- In acutely ill patients with CKD on CAPD the route for PN should be the same as in ARF patients. In these patients a combined use of PN (CHO and fat) and IPPD, using AA based PD solution can be suggested.
- In non-acutely ill malnourished CAPD patients, the preferred route is via the peritoneum.
