Nutritional Requirements for Patients with Acute Kidney Disease
Patients with acute kidney disease require individualized nutritional support with higher protein intake (1.2-1.3 g/kg/day), careful energy provision (30-40 kcal/kg/day), and specific micronutrient supplementation to reduce morbidity and mortality. 1
Protein Requirements
Protein Intake Recommendations
- Acutely ill hemodialysis patients: At least 1.2 g protein/kg/day 1
- Acutely ill peritoneal dialysis patients: At least 1.3 g protein/kg/day 1
- Patients with AKI undergoing KRT (Kidney Replacement Therapy): Higher protein needs due to increased catabolism and dialytic losses 1
Considerations for Protein Sources
- Disease-specific (renal) enteral formulas containing 70-80 g of protein/L may be preferred to reduce fluid overload 1
- In some cases, parenteral supplementation of amino acids is recommended to achieve protein goals 1
- Protein restriction (0.6-0.8 g/kg/day) should only be considered in metabolically stable patients with AKI not undergoing KRT 1
Important Clinical Pitfall
- CKD patients previously on low protein diets should NOT continue these restrictions during hospitalization for acute illness, as this can worsen protein-energy wasting and increase mortality 1
Energy Requirements
- Patients <60 years: At least 35 kcal/kg/day 1
- Patients ≥60 years: At least 30-35 kcal/kg/day 1
- Patients with acute kidney failure: 30-40 kcal/kg of ideal body weight 2
Energy Source Considerations
- Avoid overfeeding, which can worsen metabolic complications
- Consider the additional glucose load from dialysate in peritoneal dialysis patients
- Balance carbohydrate and lipid sources to prevent hyperglycemia and hypertriglyceridemia
Micronutrient Requirements
Trace Elements
- Monitor and supplement: Selenium, zinc, and copper 1
- Increased requirements during kidney failure and critical illness
- Large effluent losses during KRT necessitate supplementation 1
- For patients on CKRT >2 weeks, monitor blood copper levels and consider IV administration of ~3 mg/day 1
Water-Soluble Vitamins
- Special attention needed for: Vitamin C, folate, and thiamine 1
- Daily losses in effluent: ~68 mg vitamin C, 0.3 mg folate, 4 mg thiamine 1
- Regular supplementation required to prevent deficiencies
Electrolyte Management
Acute Oliguric Phase
Diuretic Phase
- Replace electrolyte losses as needed 2
- Monitor serum levels frequently to guide replacement
Nutritional Support Strategies
Enteral Nutrition
- Preferred route when gastrointestinal tract is functional
- Consider renal-specific formulas with higher protein content and modified electrolyte composition
- Monitor for tolerance and adequacy of nutrient delivery
Parenteral Nutrition
- Reserve for patients with non-functional gastrointestinal tract
- Adjust composition based on metabolic status and KRT modality
- Consider intradialytic parenteral amino acid supplementation when enteral route is insufficient
Monitoring Parameters
- Regular assessment of nutritional status
- Monitoring of serum electrolytes, especially potassium, phosphorus, and magnesium
- Evaluation of acid-base status
- Assessment of fluid balance
- Monitoring of nitrogen balance when feasible
Special Considerations
- Avoid protein restriction in catabolic states as it invariably worsens nitrogen balance 1
- The presence of critical illness or major surgery increases protein requirements due to hypercatabolism 1
- Nutritional management should be guided by the underlying acute illness rather than the baseline kidney condition 1
- Metabolic acidosis must be corrected to prevent further protein catabolism 1
By following these evidence-based nutritional recommendations, healthcare providers can help optimize outcomes for patients with acute kidney disease, reducing complications and potentially improving survival.