title: Resting energy expenditure after Fontan surgery in children with single-ventricle heart defects.
abstract: BACKGROUND
  Data on resting energy expenditure (REE) and oxygen consumption (VO(2)) after pediatric cardiopulmonary bypass (CPB) will facilitate optimal nutrient prescription.
  
  
  METHODS
  The authors measured continuous REE and VO(2), using an in-line indirect calorimetery (IC) in 30 consecutive children with single-ventricle physiology immediately after Fontan surgery. REE during steady state at 8 hours after surgery was compared with standard equation-estimated energy expenditure (EEE). Patients were classified into 3 groups: hypermetabolic (measured REE [MREE]/EEE ratio >1.2), hypometabolic (MREE/EEE ratio <0.8), and normometabolic (MREE/EEE ratio 0.8-1.2). Demographic, anthropometric, and perioperative clinical characteristics were examined for their correlation with metabolic status.
  
  
  RESULTS
  In 26 of 30 patients with completed IC, mean REE at 8 hours after surgery was 57 ± 20 kcal/kg/d, and mean VO(2) was 110 ± 35 mL/min. Mean values of VO(2) and REE did not change within the first 24 hours after surgery. There was poor correlation between MREE at 8 hours and the EEE using the World Health Organization equation (r = 0.32, P = .11). Most patients (n = 19, 73%) were either normometabolic or hypometabolic. Lack of hypermetabolism was significantly associated with higher intraoperative serum lactate level and positive fluid balance compared with the rest of the group.
  
  
  CONCLUSIONS
  The authors report a low prevalence of hypermetabolism in children with single-ventricle defects after Fontan surgery. Measured REE had poor correlation with equation-estimated energy expenditure in a majority of the cohort. The absence of increased energy expenditure after CPB will influence energy prescription in this group.
authors.affiliation: Division of Critical Care Medicine/Anesthesia, Department of Anesthesiology, Pain and Perioperative Medicine, Children's Hospital Boston, Harvard Medical School, Bader 634, MSICU Office, 300 Longwood Ave, Boston, MA 02115, USA. nilesh.mehta@childrens.harvard.edu
authors.forename: Nilesh M
authors.initials: NM
authors.lastname: Mehta
authors.forename: John M
authors.initials: JM
authors.lastname: Costello
authors.forename: Lori J
authors.initials: LJ
authors.lastname: Bechard
authors.forename: Victor M
authors.initials: VM
authors.lastname: Johnson
authors.forename: David
authors.initials: D
authors.lastname: Zurakowski
authors.forename: Francis X
authors.initials: FX
authors.lastname: McGowan
authors.forename: Peter C
authors.initials: PC
authors.lastname: Laussen
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Duggan
mesh_terms: D001481:Basal Metabolism; D002153:Calorimetry, Indirect; D002675:Child, Preschool; D004734:Energy Metabolism; D005260:Female; D018729:Fontan Procedure; D006330:Heart Defects, Congenital / Q000378:metabolism* / Q000601:surgery*; D006352:Heart Ventricles / Q000002:abnormalities / Q000601:surgery*; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption; D011446:Prospective Studies; D014882:Water-Electrolyte Balance
chemical_list: D019344:Lactic Acid