title: Optimal protein requirements during the first 2 weeks after the onset of critical illness.
abstract: OBJECTIVE
  To obtain optimal protein requirements in critically ill sepsis or trauma patients during the first 2 wks after admission to the intensive care unit.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Department of critical care medicine at a teaching hospital.
  
  
  METHODS
  Immediate posttrauma patients or severely septic patients.
  
  
  METHODS
  In vivo neutron activation analysis was used to measure changes in total body protein over a 10-day period which began as soon as the patients were hemodynamically stable. The patients (trauma, n=18; sepsis, n=5) were divided into three groups according to the average daily protein intakes. Because the patients were overhydrated (approximately 10 L) and had variable amounts of body fat, the protein intakes were indexed to normally hydrated (corrected) fat-free mass (FFMc): Groups A, B, and C received an average of 1.1, 1.5, and 1.9 g/kg FFMc/day protein, respectively.
  
  
  RESULTS
  Overall, the average loss of total body protein was 1.2=0.7 (SD) kg. Changes in total body protein were significantly (p=.011) different between the three groups. The loss of body protein was significantly more in group A compared with groups B (p=.013) and C (p=.023). When the protein intake was increased from 1.1 g/kg FFMc/day to 1.5 g/kg FFMc/day, protein loss was halved. Further increase in protein intake up to 1.9 g/kg FFMc/day resulted in no further improvement. An intake of 1.5 g/kg FFMc/day was equivalent to 1.0 g/day/kg of body weight measured at the beginning of the study.
  
  
  CONCLUSIONS
  Current recommended protein requirements of 1.2 to 2.0 g/kg of body weight/day are excessive if they are indexed to the body weight measured soon after the onset of critical illness. Because individual patients have varying degrees of overhydration early in the illness onset, we suggest that the intensivist should obtain information on preillness body weight and prescribe 1.2g of protein/kg body weight/day. If information is not available, 1.0g of protein/day/kg of measured body weight will give a fair approximation to optimal protein requirements.
authors.affiliation: University Department of Surgery, Auckland Hospital, New Zealand.
authors.forename: N
authors.initials: N
authors.lastname: Ishibashi
authors.forename: L D
authors.initials: LD
authors.lastname: Plank
authors.forename: K
authors.initials: K
authors.lastname: Sando
authors.forename: G L
authors.initials: GL
authors.lastname: Hill
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016470:Bacteremia / Q000178:diet therapy*; D003422:Critical Care / Q000379:methods; D016638:Critical Illness; D004044:Dietary Proteins / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009751:Nutritional Requirements; D012189:Retrospective Studies; D013997:Time Factors; D014947:Wounds and Injuries / Q000178:diet therapy*
chemical_list: D004044:Dietary Proteins