Amino acid balance with extended daily diafiltration in acute kidney injury.

Abstract

The impact of hybrid dialysis therapies on amino acid (AA) balance in critically ill patients with acute kidney injury is unknown.We examined prospectively the AA balance with extended daily diafiltration (EDDF).We studied 7 patients. AA clearances with EDDF ranged from 21.6 ml/min (tryptophan) to 66.9 ml/min (taurine). AA loss was 4.2 (IQR 1.4-12.3) g/day and 4.5% of daily protein intake for patients on enteral nutrition (EN). Percentage AA loss per hour on EDDF was highest for glutamine (32.1%) and lowest for glutamic acid (0.8%). Blood AA levels correlated with corresponding EDDF losses. Median total nitrogen appearance was 25.0 (IQR 20.6-29.3) g/day for patients on EN. This resulted in a negative nitrogen balance of -10.7 (IQR -16.6 to -1.4) g/day, of which 6.5% was attributable to AA loss.AA loss with EDDF was limited, but with much individual variability, and contributed to a strongly negative daily nitrogen balance.