Branched-chain amino acid administration in surgical patients. Effects on amino acid and fuel substrate profiles
S. P. Desai, B. R. Bistrian, J. D. Palombo, L. L. Moldawer and G. L. Blackburn
During the first five days following gastric bypass surgery, 15 patients
received near isotonic amino acid solutions that varied in their
branched-chain amino acid (BCAA) content and amino acid profiles (15.6%,
50%, or 100% BCAA solutions). Plasma valine concentrations were elevated in
patients receiving 50% and 100% BCAA solutions. Plasma alanine
concentrations were highest in patients receiving 50% BCAA. Plasma free
fatty acids and blood lactate concentrations were unchanged by either the
operation or BCAA administration. Serum glucose concentration was
unaffected by the different amino acid administrations and followed the
pattern induced by stress initially and later by starvation.
beta-Hydroxybutyrate concentrations increased as starvation proceeded and
were highest in patients receiving the 15.6% BCAA solution. Branched-chain
amino acid-enriched solutions without additional energy may be administered
safely to patients recovering from operative trauma. Plasma amino acid
concentrations and fuel substrate profiles appear to follow metabolic
patterns determined by the physiologic response to stress and starvation
and can be affected by large quantities of BCAAs.
