title: Indirect calorimetry in mechanically ventilated infants and children: accuracy of total daily energy expenditure with 2 hour measurements.
abstract: OBJECTIVE
  To determine how accurately total daily energy expenditure can be estimated from measurement periods of less than 24 h in mechanically ventilated infants and children.
  
  
  METHODS
  Prospective study to validate a method to determine energy expenditure.
  
  
  METHODS
  Pediatric intensive care unit of an university hospital.
  
  
  METHODS
  Nineteen ventilated patients (age 3 weeks - 13 years) with a FiO(2)of less than 60% and tube leakage < 10% (the difference between inspiratory and expiratory tidal volume measured by the ventilator). Separately, in five patients with varying tube leakage (2-59%) the influence of tube leakage on measured energy expenditure was determined.
  
  
  METHODS
  Energy expenditure was measured by indirect calorimetry. Total daily energy expenditure measurements for 24 h were compared with 2 h energy expenditure measurements. The influence of body temperature on measured energy expenditure was determined.
  
  
  RESULTS
  The mean coefficient of variation among 2 hour periods of measured energy expenditure was 6% (range 2-11%) compared with total daily energy expenditure measurements. The influence of body temperature revealed an increase of 6% of energy expenditure/ degrees C. An increased tube leakage influenced the energy expenditure measurements significantly (P<< 0. 001).
  
  
  CONCLUSIONS
  In a clinical situation in patients with a tube leakage << 10% total daily energy expenditure can be estimated from a 2 h measurement period.
authors.affiliation: Department of Pediatrics, Division of Pediatric Intensive Care, University Hospital Rotterdam, Rotterdam, 3000 CB, The Netherlands.
authors.forename: K F
authors.initials: KF
authors.lastname: Joosten
authors.forename: J J
authors.initials: JJ
authors.lastname: Verhoeven
authors.forename: W C
authors.initials: WC
authors.lastname: Hop
authors.forename: J A
authors.initials: JA
authors.lastname: Hazelzet
mesh_terms: D000293:Adolescent; D001831:Body Temperature; D002153:Calorimetry, Indirect / Q000592:standards; D002648:Child; D002673:Child, Hospitalized; D002675:Child, Preschool; D016638:Critical Illness; D004734:Energy Metabolism; D004868:Equipment Failure; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015278:Intensive Care Units, Pediatric; D008297:Male; D018529:Nutritional Support; D011446:Prospective Studies; D015203:Reproducibility of Results; D012121:Respiration, Artificial / Q000295:instrumentation*; D012720:Severity of Illness Index; D013997:Time Factors