title: The impact of measurement of respiratory quotient by indirect calorimetry on the achievement of nitrogen balance in patients with severe traumatic brain injury.
abstract: BACKGROUND
  This study evaluated the impact of IC on the optimization of nutritional support and the achievement of +NB in patients with TBI.
  
  
  METHODS
  27 patients (GCS ≤ 8), treated with a 5-day multimodality monitoring and goal-directed therapy protocol, received enteral nutrition on day 1 followed by IC on days 3 and 5 and assessment of NB on day 7. In the first cohort (n = 11), no adjustment in kcal was made. In the second cohort (n = 16), nutrition was targeted to an RQ of 0.83 by day 3. The first cohort was analyzed with respect to NB status; the second cohort was compared to patients with (-) and +NB of the first cohort. Data (mean ± SD) were analyzed with unpaired t test, and Chi square and Fisher exact tests.
  
  
  RESULTS
  4/11(36 %) patients in the first cohort had +NB. The predicted mortality by TRISS, substrate utilization, and RQ was significantly lower compared to the second cohort. The mortality predicted by the CrasH model did not differ between the two cohorts. A RQ of 0.74 was associated with the preferential use of fat and protein and -NB, whereas a RQ of 0.84 favored utilization of carbohydrates and +NB. All patients whose kcal intake was adjusted based on the RQ on day 3 reached a +NB by day 7.
  
  
  CONCLUSIONS
  An increase in kcal ≥25 % in patients with a RQ < 0.83 on day 3 improves substrate utilization, decreases protein utilization and optimizes the achievement of +NB by day 7.
authors.affiliation: Division of Trauma Surgery, Surgical Critical Care and Acute Care Surgery, Department of Surgery New York Medical College, Joel A. Halpern Trauma Center, Westchester Medical Center University Hospital, 100 Woods Rd Taylor Pavilion E 138, Valhalla, New York, 10595, USA.
authors.forename: J
authors.initials: J
authors.lastname: Maxwell
authors.affiliation: Division of Trauma Surgery, Surgical Critical Care and Acute Care Surgery, Department of Surgery New York Medical College, Joel A. Halpern Trauma Center, Westchester Medical Center University Hospital, 100 Woods Rd Taylor Pavilion E 138, Valhalla, New York, 10595, USA.
authors.forename: C
authors.initials: C
authors.lastname: Gwardschaladse
authors.affiliation: Division of Trauma Surgery, Surgical Critical Care and Acute Care Surgery, Department of Surgery New York Medical College, Joel A. Halpern Trauma Center, Westchester Medical Center University Hospital, 100 Woods Rd Taylor Pavilion E 138, Valhalla, New York, 10595, USA.
authors.forename: G
authors.initials: G
authors.lastname: Lombardo
authors.affiliation: Division of Trauma Surgery, Surgical Critical Care and Acute Care Surgery, Department of Surgery New York Medical College, Joel A. Halpern Trauma Center, Westchester Medical Center University Hospital, 100 Woods Rd Taylor Pavilion E 138, Valhalla, New York, 10595, USA.
authors.forename: P
authors.initials: P
authors.lastname: Petrone
authors.affiliation: Division of Trauma Surgery, Surgical Critical Care and Acute Care Surgery, Department of Surgery New York Medical College, Joel A. Halpern Trauma Center, Westchester Medical Center University Hospital, 100 Woods Rd Taylor Pavilion E 138, Valhalla, New York, 10595, USA.
authors.forename: A
authors.initials: A
authors.lastname: Policastro
authors.affiliation: Division of Trauma Surgery, Surgical Critical Care and Acute Care Surgery, Department of Surgery New York Medical College, Joel A. Halpern Trauma Center, Westchester Medical Center University Hospital, 100 Woods Rd Taylor Pavilion E 138, Valhalla, New York, 10595, USA.
authors.forename: D
authors.initials: D
authors.lastname: Karev
authors.affiliation: Division of Trauma Surgery, Surgical Critical Care and Acute Care Surgery, Department of Surgery New York Medical College, Joel A. Halpern Trauma Center, Westchester Medical Center University Hospital, 100 Woods Rd Taylor Pavilion E 138, Valhalla, New York, 10595, USA.
authors.forename: K
authors.initials: K
authors.lastname: Prabhakaran
authors.affiliation: Division of Trauma Surgery, Surgical Critical Care and Acute Care Surgery, Department of Surgery New York Medical College, Joel A. Halpern Trauma Center, Westchester Medical Center University Hospital, 100 Woods Rd Taylor Pavilion E 138, Valhalla, New York, 10595, USA.
authors.forename: A
authors.initials: A
authors.lastname: Betancourt
authors.affiliation: Division of Trauma Surgery, Surgical Critical Care and Acute Care Surgery, Department of Surgery New York Medical College, Joel A. Halpern Trauma Center, Westchester Medical Center University Hospital, 100 Woods Rd Taylor Pavilion E 138, Valhalla, New York, 10595, USA. marinic@wcmc.com.
authors.forename: C P
authors.initials: CP
authors.lastname: Marini
mesh_terms: D000328:Adult; D000070642:Brain Injuries, Traumatic / Q000401:mortality*; D002153:Calorimetry, Indirect; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D009584:Nitrogen / Q000378:metabolism*; D009752:Nutritional Status; D018529:Nutritional Support; D010101:Oxygen Consumption; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D009584:Nitrogen
keywords: Indirect calorimetry; Nitrogen balance; Respiratory quotient; Severe traumatic brain injury