title: An observational near-infrared spectroscopy study on cerebral autoregulation in post-cardiac arrest patients: time to drop 'one-size-fits-all' hemodynamic targets?
abstract: OBJECTIVE
  A subgroup of patients with ROSC after cardiac arrest (CA) with disturbed cerebral autoregulation might benefit from higher mean arterial pressures (MAP). We aimed to (1) phenotype patients with disturbed autoregulation, (2) investigate whether these patients have a worse prognosis, (3) define an individual optimal MAP per patient and (4) investigate whether time under this individual optimal MAP is associated with outcome.
  
  
  METHODS
  Prospective observational study in 51 post-CA patients monitored with near infrared spectroscopy.
  
  
  RESULTS
  (1) 18/51 patients (35%) had disturbed autoregulation. Phenotypically, a higher proportion of patients with disturbed autoregulation had pre-CA hypertension (31±47 vs. 65±49%, p=0.02) suggesting that right shifting of autoregulation is caused by chronic adaptation of cerebral blood flow to higher blood pressures. (2) In multivariate analysis, patients with preserved autoregulation (n=33, 65%) had a significant higher 180-days survival rate (OR 4.62, 95% CI [1.06:20.06], p=0.04]. Based on an index of autoregulation (COX), the average COX-predicted optimal MAP was 85 mmHg in patients with preserved and 100 mmHg in patients with disturbed autoregulation. (3) An individual optimal MAP could be determined in 33/51 patients. (4) The time under the individual optimal MAP was negatively associated with survival (OR 0.97, 95% CI [0.96:0.99], p=0.02). The time under previously proposed fixed targets (65, 70, 75, 80 mmHg) was not associated with a differential survival rate.
  
  
  CONCLUSIONS
  Cerebral autoregulation showed to be disturbed in 35% of post-CA patients of which a majority had pre-CA hypertension. Disturbed cerebral autoregulation within the first 24h after CA is associated with a worse outcome. In contrast to uniform MAP goals, the time spent under a patient tailored optimal MAP, based on an index of autoregulation, was negatively associated with survival.
authors.affiliation: Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium. Electronic address: Koen.ameloot@zol.be.
authors.forename: K
authors.initials: K
authors.lastname: Ameloot
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Ziekenhuis Oost-Limburg, Genk, Belgium; Faculty of Medicine and Life Sciences, University Hasselt, Diepenbeek, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Genbrugge
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Ziekenhuis Oost-Limburg, Genk, Belgium; Faculty of Medicine and Life Sciences, University Hasselt, Diepenbeek, Belgium.
authors.forename: I
authors.initials: I
authors.lastname: Meex
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Ziekenhuis Oost-Limburg, Genk, Belgium; Faculty of Medicine and Life Sciences, University Hasselt, Diepenbeek, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Jans
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Ziekenhuis Oost-Limburg, Genk, Belgium.
authors.forename: W
authors.initials: W
authors.lastname: Boer
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Ziekenhuis Oost-Limburg, Genk, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Vander Laenen
authors.affiliation: Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Ferdinande
authors.affiliation: Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium; Faculty of Medicine and Life Sciences, University Hasselt, Diepenbeek, Belgium.
authors.forename: W
authors.initials: W
authors.lastname: Mullens
authors.affiliation: Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Dupont
authors.affiliation: Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium; Faculty of Medicine and Life Sciences, University Hasselt, Diepenbeek, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Dens
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Ziekenhuis Oost-Limburg, Genk, Belgium; Faculty of Medicine and Life Sciences, University Hasselt, Diepenbeek, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: DeDeyne
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006323:Heart Arrest / Q000401:mortality / Q000503:physiopathology*; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D064926:Neurophysiological Monitoring; D011446:Prospective Studies; D019265:Spectroscopy, Near-Infrared
keywords: Autoregulation; Cerebral blood flow; Hemodynamic targets; Post-cardiac arrest