title: Can an adequate energy intake be able to reverse the negative nitrogen balance in mechanically ventilated critically ill patients?
abstract: OBJECTIVE
  Adequate energy provision and nitrogen losses prevention of critically ill patients are essentials for treatment and recovery. The aims of this study were to evaluate energy expenditure (EE) and nitrogen balance (NB) of critically ill patients, to classify adequacy of energy intake (EI), and to verify adequacy of EI capacity to reverse the negative NB.
  
  
  METHODS
  Seventeen patients from an intensive care unit were evaluated within a 24-hour period. Indirect calorimetry was performed to calculate patient's EE and Kjeldhal for urinary nitrogen analysis. The total EI and protein intake were calculated from the standard parenteral and enteral nutrition infused. Underfeeding was characterized as EI 90% or less and overfeeding as 110% or greater of EE. The adequacy of the EI (EI EE(-1) × 100) and the NB were estimated and associated with each other by Spearman coefficient.
  
  
  RESULTS
  The mean EE was 1515 ± 268 kcal d(-1), and most of the patients (11/14) presented a negative NB (-8.2 ± 4.7 g.d(-1)). A high rate (53%) of inadequate energy intake was found, and a positive correlation between EI EE(-1) and NB was observed (r = 0.670; P = .007).
  
  
  CONCLUSIONS
  The results show a high rate of inadequate EI and negative NB, and equilibrium between EI and EE may improve NB. Indirect calorimetry can be used to adjust the energy requirements in the critically ill patients.
authors.affiliation: Division of Intensive Care, Department of Surgery and Anatomy, Faculty of Medicine of Ribeirão Preto-University of São Paulo, SP 14049-900 Ribeirão Preto, Brazil. camila@fmrp.usp.br
authors.forename: Camila C
authors.initials: CC
authors.lastname: Japur
authors.forename: Jacqueline P
authors.initials: JP
authors.lastname: Monteiro
authors.forename: Júlio Sérgio
authors.initials: JS
authors.lastname: Marchini
authors.forename: Rosa Wanda Diez
authors.initials: RW
authors.lastname: Garcia
authors.forename: Anibal
authors.initials: A
authors.lastname: Basile-Filho
mesh_terms: D000328:Adult; D000368:Aged; D002153:Calorimetry, Indirect; D003422:Critical Care; D016638:Critical Illness; D003430:Cross-Sectional Studies; D004044:Dietary Proteins / Q000008:administration & dosage / Q000378:metabolism; D002149:Energy Intake; D004734:Energy Metabolism; D004750:Enteral Nutrition; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009584:Nitrogen / Q000378:metabolism* / Q000652:urine; D010288:Parenteral Nutrition; D012121:Respiration, Artificial; D016896:Treatment Outcome
chemical_list: D004044:Dietary Proteins; D009584:Nitrogen