The determinants of protein catabolism in neonates on extracorporeal membrane oxygenation

Background/Purpose: Protein catabolism appears to be markedly elevated amon g neonates on extracorporeal membrane oxygenation (ECMO). The aim of this s tudy was to determine the effect of dietary caloric intake on protein catab olism in neonates on ECMO to help construct therapies that may promote anab olism. Methods: Twelve total parenteral nutrition (TPN)-fed (88.1 +/- 5.0 [SE] kca l/kg/d; range, 60 to 113 kcal/kg/d; 2.3 +/- 0.2 g/kg/d protein) neonates we re studied on ECMO at day of life 7.2 +/- 0.8 d. Protein kinetics were dete rmined using infusions of (NaHCO3)-C-13 and 1-[C-13]leucine. Results: As expected, C-reactive protein levels were significantly elevated compared with normal controls (44.0 +/- 7.6 mg/L v 1.9 +/- 1.1 mg/L; P < . 001). Negative protein balance (-2.3 +/- 0.6 g/kg/dt range, 1 to -6.4 g/kg/ d) highly correlated (r = -0.88, P < .001) with total protein turnover. Inc reased dietary caloric intake correlated with increased amino acid oxidatio n (r = 0.85, P < .001), increased total protein turnover (r = 0.73, P < .01 ), continued negative protein balance (r = 0.72, P < .01), increased whole- body protein breakdown (r = 0.66, P < .05), and increased CO2 production ra te (r = 0.73, P < .01). Conclusions: A surplus of dietary caloric intake does not improve protein c atabolism and merely increases CO2 production in these highly stressed neon ates. Thus, judicious caloric supplementation is warranted. J Pediatr Surg 34:1086-1090. Copyright (C) 1999 by W.B. Saunders Company.