Loss of Amino Acids Into Dialysate During Hemodialysis Using Hydrophilic and Nonhydrophilic Polyester–Polymer Alloy and Polyacrylonitrile Membrane Dialyzers

Abstract

During hemodialysis, amino acid loss through the dialysate remained a significant problem and was not clear in some dialyzers; therefore, we investigated amino acid loss with hydrophilic and nonhydrophilic polyester-polymer alloy membranes and polyacrylonitrile membranes. Nine maintenance hemodialysis patients were studied to assess amino acid loss during hemodialysis with the three membranes. Total amino acid losses were 85.7 ± 27.2 mg/L, 83.3 ± 16.1 mg/L, and 72.1 ± 22.5 mg/L with the hydrophilic, nonhydrophilic polyester-polymer alloy, and polyacrylonitrile membranes, respectively. Amino acid losses were greater with the hydrophilic membrane compared with the polyacrylonitrile membrane for ornithine (2.0 ± 0.6 vs. 1.4 ± 0.4 mg/L, P = 0.025), phenylalanine (2.4 ± 0.9 vs. 1.8 ± 0.8 mg/L, P = 0.012), and tryptophan (0.6 ± 0.2 vs. 0.4 ± 0.2 mg/L, P = 0.023). Amino acid losses were greater with the nonhydrophilic membrane than with the polyacrylonitrile membrane for ornithine (2.0 ± 0.4 vs. 1.4 ± 0.4 mg/L, P = 0.017), phenylalanine (2.3 ± 0.5 vs. 1.8 ± 0.8 mg/L, P = 0.018), tryptophan (0.7 ± 0.2 vs. 0.4 ± 0.2 mg/L, P = 0.003), and cystine (3.2 ± 0.7 vs. 2.0 ± 0.7 mg/L, P = 0.005). In conclusion, greater losses of ornithine, phenylalanine, tryptophan, and cystine were observed with polyester-polymer alloy than with polyacrylonitrile membranes during hemodialysis. Constant attention should be paid to the amino acid loss profile to improve nutritional control in hemodialysis patients.

Plasma Cystine Levels and Cardiovascular and All‐Cause Mortality in Hemodialysis Patients

“…Malnutrition in HD patients can be caused by combinations of multiple related factors, such as insufficient nutrient intake and metabolic acidosis (16). In addition, as we previously reported, loss of AAs, including CySS, through dialysate inevitably occurs during every HD session (12). In spite of these multifactorial influences on the AA profile, CySS levels were able to show an independent significance in predicting mortality, indicating that CySS levels have a critical role in oxidative stress even in the specific AA profiles of HD patients as well as non-HD patients.…”

“…Pre‐dialysis fasting blood samples were collected to examine the amino acids (AA) in the blood from arterial blood lines at the beginning of a week. We measured plasma AA and CySS levels as previously reported . HD‐associated hypotension was defined as a decrease in the systolic blood pressure by 20 mm Hg or a decrease in the mean arterial pressure (MAP) by 10 mm Hg associated with symptoms that include abdominal discomfort, yawning, sighing, nausea, vomiting, muscle cramps, restlessness, dizziness or fainting, and anxiety.…”

“…AA analysis was previously described in detail . Pre‐dialysis blood samples were collected from the arterial blood lines for the AA profiles.…”

DGEM-Leitlinie: „Klinische Ernährung in der Intensivmedizin“

“…Unter Einsatz einer "Sustained low efficiency dialysis (SLED)" liegt der Verlust an Aminosäuren laut einer Untersuchung in derselben Größenordnung wie bei kontinuierlichen Nierenersatzverfahren [148]. In Abhängigkeit von der Art der eingesetzten Filtermembranen kann es jedoch zu einem unterschiedlich hohen Verlust spezifischer Aminosäuren kommen [149].…”

Dietary Protein and Physical Activity Interventions to Support Muscle Maintenance in End-Stage Renal Disease Patients on Hemodialysis

“…During HD, both metabolic waste products as well as circulating amino acids are able to diffuse through the semipermeable dialysis membrane [11]. The diffusion into the dialysate results in a considerable extraction of circulating amino acids throughout HD [30,[53][54][55][56]. We have recently shown that during a single HD session,~12 g amino acids are extracted from the circulation in CHD patients who ingest their habitual diet during HD [57].…”