title: Resting energy expenditure and substrate oxidation rates correlate to temperature and outcome after cardiac arrest - a prospective observational cohort study.
abstract: BACKGROUND
  Targeted temperature management improves outcome after cardiopulmonary resuscitation. Reduction of resting energy expenditure might be one mode of action. The aim of this study was to correlate resting energy expenditure and substrate oxidation rates with targeted temperature management at 33°C and outcome in patients after cardiac arrest.
  
  
  METHODS
  This prospective, observational cohort study was performed at the department of emergency medicine and a medical intensive care unit of a university hospital. Patients after successful cardiopulmonary resuscitation undergoing targeted temperature management at 33°C for 24 hours with subsequent rewarming to 36°C and standardized sedation, analgesic and paralytic medication were included. Indirect calorimetry was performed five times within 48 h after cardiac arrest. Measurements were correlated to outcome with repeated measures ANOVA, linear and logistic regression analysis.
  
  
  RESULTS
  In 25 patients resting energy expenditure decreased 20 (18 to 27) % at 33°C compared to 36°C without differences between outcome groups (favourable vs. unfavourable: 25 (21 to 26) vs. 21 (16 to 26); P = 0.5). In contrast to protein oxidation rate (favourable vs. unfavourable: 35 (11 to 68) g/day vs. 39 (7 to 75) g/day, P = 0.8) patients with favourable outcome had a significantly higher fat oxidation rate (139 (104 to 171) g/day vs. 117 (70 to 139) g/day, P <0.05) and a significantly lower glucose oxidation rate (30 (-34 to 88) g/day vs. 77 (19 to 138) g/day; P < 0.05) as compared to patients with unfavourable neurological outcome.
  
  
  CONCLUSIONS
  Targeted temperature management at 33°C after cardiac arrest reduces resting energy expenditure by 20% compared to 36°C. Glucose and fat oxidation rates differ significantly between patients with favourable and unfavourable neurological outcome.
  
  
  BACKGROUND
  Clinicaltrials.gov NCT00500825. Registered 11 July 2007.
authors.affiliation: Department of Medicine III, Division of Gastroenterology and Hepatology, ICU 13H1, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria. ulrike.holzinger@meduniwien.ac.at.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Holzinger
authors.affiliation: Department of Medicine III, Division of Gastroenterology and Hepatology, ICU 13H1, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria. richard.brunner@meduniwien.ac.at.
authors.forename: Richard
authors.initials: R
authors.lastname: Brunner
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria. heidrun.losert@meduniwien.ac.at.
authors.forename: Heidrun
authors.initials: H
authors.lastname: Losert
authors.affiliation: Department of Intensive Care, University Medical Center Hamburg-Eppendorf, Martinistraße 52, Hamburg, 20246, Germany. v.fuhrmann@uke.de.
authors.forename: Valentin
authors.initials: V
authors.lastname: Fuhrmann
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria. harald.herkner@meduniwien.ac.at.
authors.forename: Harald
authors.initials: H
authors.lastname: Herkner
authors.affiliation: Department of Medicine III, Division of Gastroenterology and Hepatology, ICU 13H1, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria. christian.madl@meduniwien.ac.at.
authors.forename: Christian
authors.initials: C
authors.lastname: Madl
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria. fritz.sterz@meduniwien.ac.at.
authors.forename: Fritz
authors.initials: F
authors.lastname: Sterz
authors.affiliation: Department of Medicine III, Division of Gastroenterology and Hepatology, ICU 13H1, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria. bruno.schneeweiss@yahoo.de.
authors.forename: Bruno
authors.initials: B
authors.lastname: Schneeweiß
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000759:Adjuvants, Anesthesia / Q000627:therapeutic use; D000732:Androstanols / Q000627:therapeutic use; D001831:Body Temperature; D002153:Calorimetry, Indirect; D016887:Cardiopulmonary Resuscitation; D015331:Cohort Studies; D004734:Energy Metabolism; D005260:Female; D005283:Fentanyl / Q000627:therapeutic use; D005947:Glucose / Q000378:metabolism; D006323:Heart Arrest / Q000628:therapy*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D007036:Hypothermia, Induced; D008297:Male; D008874:Midazolam / Q000627:therapeutic use; D003473:Neuromuscular Nondepolarizing Agents / Q000627:therapeutic use; D010084:Oxidation-Reduction; D011506:Proteins / Q000378:metabolism; D012146:Rest; D017694:Rewarming; D000077123:Rocuronium
chemical_list: D000759:Adjuvants, Anesthesia; D000732:Androstanols; D006993:Hypnotics and Sedatives; D003473:Neuromuscular Nondepolarizing Agents; D011506:Proteins; D005947:Glucose; D008874:Midazolam; D005283:Fentanyl; D000077123:Rocuronium