The metabolic response to intravenous medium-chain triglycerides in infants after surgery.
OBJECTIVE
The aim of this study was to determine if administration of mixed medium-chain triglycerides (MCT)/long chain triglycerides (LCT) fat emulsion would increase net fat oxidation and if carbohydrate intake would influence net fat oxidation.


METHODS
Stable infants receiving total parenteral nutrition were studied after surgery. Respiratory gas exchange was measured by indirect calorimetry and urinary nitrogen excretion by the micro-Kjeldahl method. Intravenous fat (4 g/kg/day) was given as either pure LCT fat emulsion or 50/50 MCT/LCT fat emulsion. Carbohydrate intake was either "high" (15 g/kg/day) or "low" (10 g/kg/day). Four groups of patients were studied: group 1 = LCT and high-carbohydrate; group 2 = LCT and low-carbohydrate; group 3 = MCT/LCT and high-carbohydrate; group 4 = MCT/LCT and low-carbohydrate.


RESULTS
At a carbohydrate intake of 15 g/kg/day, the calories available from glucose exceeded the measured resting energy expenditure (REE), and no differences were seen in either energy expenditure or net fat oxidation between patients receiving LCT and MCT/LCT fat emulsions. However, at a carbohydrate intake of 10 g/kg/day, when glucose calories were less than REE, net fat oxidation was significantly higher in patients receiving MCT/LCT (median, 1.94; range, 1.05-2.24 g/kg/day) compared with patients receiving LCT (median, 0.60; range, -0.09 to 1.35; P =.03).


CONCLUSIONS
Providing that carbohydrate calories do not exceed REE, partial replacement of LCT by MCT in intravenous fat emulsions can increase net fat oxidation in infants after surgery.
Donnell
Stephen C
SC
Department of Child Health, University of Liverpool and Alder Hey Children's Hospital, Liverpool, England, United Kingdom.
Lloyd
David A
DA
Eaton
Simon
S
Pierro
Agostino
A
D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004065:Digestive System Abnormalities; D013505:Digestive System Surgical Procedures; D004734:Energy Metabolism; D005217:Fat Emulsions, Intravenous / Q000627:therapeutic use*; D005767:Gastrointestinal Diseases / Q000378:metabolism / Q000601:surgery; D006801:Humans; D007223:Infant; D010289:Parenteral Nutrition, Total; D011184:Postoperative Period; D014280:Triglycerides / Q000008:administration & dosage*
D004040:Dietary Carbohydrates; D005217:Fat Emulsions, Intravenous; D014280:Triglycerides