title: Energy expenditure after 2- to 3-hour elective surgical operations.
abstract: Energy expenditure was measured by indirect calorimetry in 17 adult patients (8 women and 9 men) before surgery, 4 hours immediately after surgery, and 24 hours late after surgery in patients undergoing elective surgery of small-to-medium scope.
  
  
  METHODS
  The total duration of surgery ranged from 2 to 3 hours. Repeated measures were performed on the same patient, so that each patient was considered to be his/her own control. All patients received a 5% dextrose solution (2000 mL/day) throughout the postoperative period.
  
  
  RESULTS
  Men showed a reduction in CO2 production during the immediately after surgery period (257+/-42 mL/min) compared to before surgery (306+/-48 mL/min) and late after surgery (301+/-45 mL/min); this reduction was not observed in women. Energy expenditure was also lower in men during immediately after surgery (6.6 kJ/min). None of the other measurements, including substrate oxidation, showed significant differences.
  
  
  CONCLUSIONS
  Therefore, elective surgery itself cannot be considered an important trauma that would result in increased energy expenditure. According to this study, it is not necessary to prescribe an energy supply exceeding basal expenditure during the immediate after-surgery period. The present results suggest that the energy supply prescribed during the postoperative period after elective surgery of small-to-medium scope should not exceed 5-7 kJ/min, so the patient does not receive a carbohydrate overload from energy supplementation.
authors.affiliation: Medical School of Ribeirão Preto, University of São Paulo.
authors.forename: A F
authors.initials: AF
authors.lastname: Tannus
authors.forename: R L
authors.initials: RL
authors.lastname: Valença de Carvalho
authors.forename: V M
authors.initials: VM
authors.lastname: Suen
authors.forename: J B
authors.initials: JB
authors.lastname: Cardoso
authors.forename: N
authors.initials: N
authors.lastname: Okano
authors.forename: J S
authors.initials: JS
authors.lastname: Marchini
mesh_terms: D000293:Adolescent; D000328:Adult; D001481:Basal Metabolism / Q000502:physiology; D002153:Calorimetry, Indirect / Q000379:methods; D017558:Elective Surgical Procedures / Q000379:methods*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005947:Glucose / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D017678:Sex Distribution; D013997:Time Factors
chemical_list: D005947:Glucose