Methionine Splanchnic Uptake Is Increased In Critically Ill Children

During critical illness the splanchnic area is profoundly affected. There is no information on splanchnic uptake of amino acids in vivo, in critically ill children. Hypothesis: Methionine splanchnic uptake in critically ill children will differ from estimates in healthy adults. Methods: We studied 24 critically ill children. Eight infants (age 6±3months; wt 6±1.4 kg), eight children (age 5±2 y; wt 14±3 kg and 8 adolescents (15±1.94 y; wt 63.3±21kg), who received continuous enteral feedings, providing protein and energy intake at full maintenance needs. We conducted a simultaneous, intravenous, primed, constant, 9h tracer infusion of L‐[ 2 H 3 methyl] methionine at 2.5 μmol.kg −1 h 1 and enteral infusion of L‐[ 13 C] methionine at 5μmol.kg −1 h 1 . Results: Plasma methionine fluxes obtained with the enteral 13 C and the intravenous 2 H 3 labels were 85±13 and 30±8, 71±5 and 41±15, and 68±7 and 35±7 μmol.kg −1 h −1 , respectively for infants, children and adolescents. First pass disappearance of methionine tracer, respectively, was 63, 43 and 47%. The rates of intestinal methionine oxidation were 24±10, 18±6 and 23±8 μmol.kg −1 h 1 Conclusions: Methionine splanchnic uptake is higher in critically ill infants when compared to children and adolescents (p<0.05), and higher than values of about 15% reported in healthy adults. NIH DK‐62363, T32 HD‐007445, Ajinomoto 3‐ARP; USDA/ARS 25337387, Sophia Foundation for Scientific Research