Amino acids - Guidelines on Parenteral Nutrition, Chapter 4.

Protein catabolism should be reduced and protein synthesis promoted with parenteral nutrion (PN). Amino acid (AA) solutions should always be infused with PN. Standard AA solutions are generally used, whereas specially adapted AA solutions may be required in certain conditions such as severe disorders of AA utilisation or in inborn errors of AA metabolism. An AA intake of 0.8 g/kg/day is generally recommended for adult patients with a normal metabolism, which may be increased to 1.2-1.5 g/kg/day, or to 2.0 or 2.5 g/kg/day in exceptional cases. Sufficient non-nitrogen energy sources should be added in order to assure adequate utilisation of AA. A nitrogen calorie ratio of 1:130 to 1:170 (g N/kcal) or 1:21 to 1:27 (g AA/kcal) is recommended under normal metabolic conditions. In critically ill patients glutamine should be administered parenterally if indicated in the form of peptides, for example 0.3-0.4 g glutamine dipeptide/kg body weight/day (=0.2-0.26 g glutamine/kg body weight/day). No recommendation can be made for glutamine supplementation in PN for patients with acute pancreatitis or after bone marrow transplantation (BMT), and in newborns. The application of arginine is currently not warranted as a supplement in PN in adults. N-acetyl AA are only of limited use as alternative AA sources. There is currently no indication for use of AA solutions with an increased content of glycine, branched-chain AAs (BCAA) and ornithine-alpha-ketoglutarate (OKG) in all patients receiving PN. AA solutions with an increased proportion of BCAA are recommended in the treatment of hepatic encephalopathy (III-IV).

Alanyl-glutamine dipeptide does not affect hemodynamics despite a greater increase in myocardial heat shock protein 72 immunoreactivity in endotoxemic sheep.

The possible beneficial effect of supplemental glutamine (Gln) in critically ill patients has been suggested to be mediated by the induction of the cytoprotective heat shock proteins (HSP)32 and HSP72. There is evidence that HSP72 and HSP32 have opposite effects on the hemodynamic situation during endotoxemia. Therefore, the effect of Gln supplementation on the cardiovascular system is not clear. We investigated the effect of alanyl-Gln (Ala-Gln) dipeptide on cardiovascular function in healthy and endotoxemic sheep. Ten sheep catheterized for chronic studies received Ala-Gln 700 mg/(kg x d) [equal to 470 mg/(kg x d)Gln] on 4 consecutive days, and 10 sheep received NaCl (9 g/L) as the control solution. On d 4, four sheep of each group were killed and myocardial samples were taken for immunohistochemistry. The remaining sheep received a continuous infusion of endotoxin [Salmonella typhosa, 10 ng/(kg x min)]. Hemodynamic parameters were measured before application of Ala-Gln or the control solution, and during endotoxemia. Myocardial HSP72 immunoreactivity was determined by immunohistochemistry. After 24 h of endotoxemia, the sheep exhibited a hyperdynamic circulation. No difference was found in the hemodynamic parameters between treatment and control group. Ala-Gln treated sheep had a greater increase in myocardial HSP72 immunoreactivity compared with controls after (P < 0.05) but not before endotoxemia. In summary, Ala-Gln increased HSP72 immunoreactivity after endotoxemia, but did not alter hemodynamic parameters. Thus, Ala-Gln supplementation does not seem to aggravate the hyperdynamic circulation in endotoxemic shock.

Cost containment through L-alanyl-L-glutamine supplemented total parenteral nutrition after major abdominal surgery: a prospective randomized double-blind controlled study.

BACKGROUND & AIMS: Glutamine is recognized as a conditionally essential amino acid. Recent studies indicate that glutamine-containing total parenteral nutrition improves nitrogen economy, enhances gastrointestinal and immune functions and shortens hospital stay. METHODS: Thirty-seven patients (19 w and 18 m; age 61. 4+/-10.4 years; BMI 23.7+/-2.8 kg/m(2)) following major abdominal surgery receiving an isonitrogenous isoenergetic TPN with or without alanyl-glutamine supplementation (0.5 g/kg BW/day), were evaluated in a double-blind, randomized, controlled trial over a five-day period by measuring nitrogen balance, selected biochemical parameters and length of hospital stay. RESULTS: Supplemental alanyl-glutamine improved the overall mean (-3.5+/-1.6 vs. -5.5+/-1. 4 g N;P<0.05) and cumulative nitrogen balance (-14.1+/-9.1 vs. -21.7+/-11.4 g N;P<0.05) compared with the isonitrogenous, isoenergetic standard regimen. Alanyl-glutamine normalized plasma glutamine concentration and reduced the length of hospital stay (12.8+/-2.6 vs. 17.5+/-6.4 days;P<0.05). CONCLUSIONS: The results of the study confirm that supplementation with synthetic alanyl-glutamine dipeptide is associated with cost containment due to shortened hospitalization and improved nitrogen economy.