High protein intake during continuous hemodiafiltration: impact on amino acids and nitrogen balance

Int J Artif Organs. 2002 Apr;25(4):261-8. doi: 10.1177/039139880202500403.


Aims: To study the effect of combined continuous veno-venous hemodiafiltration (CVVHDF) and high (2.5 g/kg/day) parenteral amino acid supplementation on nitrogen balance, amino acid losses and azotemic control in a cohort of patients with severe acute renal failure (ARF).

Methods: We administered 2.5 grams/kg/day of amino acids intravenously to seven critically ill patients with ARF. We obtained paired blood and ultrafiltrate (UF) samples (n=20) and calculated amino acid clearances and losses, nitrogen balance, protein catabolic rate and total nitrogen losses.

Results: The median total serum amino acid concentration was high at 5.2 mmol/L with particularly high concentrations of ornithine, lysine, and phenylalanine, but a low level of histidine. The median overall amino acid clearance was 18.6 ml/min (range: 12 to 29 ml/min). UF losses as percentage of administered dose were high for tyrosine (53.6%) but low for methionine (3.0%) and arginine (2.3%). A positive nitrogen balance was achieved in 7 (35%) of the 20 study days with an overall median nitrogen balance of -1.8 g/day. Urea levels were maintained at a median of 26.6 mmol/L.

Conclusions: High protein intake increases the serum concentrations of most amino acids. Such protein supplementation, when coupled with CVVHDF achieves a slightly negative overall nitrogen balance in extremely catabolic patients while still allowing adequate azotemic control.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Kidney Injury / metabolism*
  • Acute Kidney Injury / therapy
  • Adult
  • Aged
  • Amino Acids / administration & dosage*
  • Amino Acids / blood*
  • Dietary Proteins / administration & dosage*
  • Electrolytes
  • Female
  • Food, Formulated*
  • Glucose
  • Hemodiafiltration*
  • Humans
  • Male
  • Middle Aged
  • Nitrogen / metabolism*
  • Parenteral Nutrition Solutions
  • Parenteral Nutrition*
  • Solutions


  • Amino Acids
  • Dietary Proteins
  • Electrolytes
  • Parenteral Nutrition Solutions
  • Solutions
  • amino-acid, glucose, and electrolyte solution
  • Glucose
  • Nitrogen