Albumin synthesis rates in post-surgical infants and septic adolescents; influence of amino acids, energy, and insulin

Background & aims: To investigate the effects of glucose, parenteral amino acids, and intravenous insulin on albumin synthesis rates in critically ill children. Methods: Two studies were performed in 8 post-surgical infants (age 9.8 ± 1.9 months; weight 9.5 ± 1.1 kg) and 9 septic adolescents (age 15 ± 1 yr; BMI 23 ± 4 kg m ^-2), respectively. All received a primed, constant, tracer infusion with [1- ¹³C]Leucine. The infants in study 1 were randomized to receive low (2.5 mg kg ^-1 min ^-1) and standard (5.0 mg kg ^-1 min ^-1) glucose intake in a cross-over setting of two periods of 4 h each. The adolescents in study 2 were randomized to receive total parenteral nutrition with standard (1.5 g kg ^-1 day ^-1) and high (3.0 g kg ^-1 day ^-1) amino acid intake in a two day cross-over setting. On both study days, during the last 3 h of the tracer study, they received insulin infused at 80 mU m ^-2 min ^-1. Results: The post-surgical infants and the septic adolescents were mildly hypoalbuminemic (∼2.5 g dL ^-1) with high synthesis rates, which were not affected by different intakes of glucose, amino acids, or insulin infusion. Conclusions: Albumin synthesis rates in hypoalbuminemic critically ill children are high but were not upregulated through nutrient supply, and in septic adolescents are unaffected by insulin.