title: Association between blood pressure and outcomes in patients after cardiac arrest: A systematic review.
abstract: OBJECTIVE
  Hypoxic ischaemic brain injury (HIBI) is a major cause of disability after cardiac arrest. HIBI leads to impaired cerebral autoregulation such that adequate cerebral perfusion becomes critically dependent on blood pressure. However, the optimal blood pressure after cardiac arrest remains unclear. Therefore, we conducted a systematic review to investigate the association between blood pressure and neurologic outcome patients after cardiac arrest.
  
  
  METHODS
  We systematically searched MEDLINE, EMBASE, conference abstracts and article references to identify randomized and observational studies investigating the relationship between blood pressure and neurologic outcome. We included studies that reported adjusted point estimates for the relationship between blood pressure and neurologic status in adult patients after cardiac arrest.
  
  
  RESULTS
  We included 9 studies with a total of 13,150 patients. Three studies included only patients with an out-of-hospital cardiac arrest. There was marked between-study heterogeneity with respect to blood pressure definition (MAP vs. systolic), exposure duration and modelling (dichotomous vs. continuous). All studies examined either mortality or neurological status as an outcome. Seven of nine studies demonstrated that higher blood pressure was associated with improved outcomes either by an association between higher MAP and good neurologic outcome or the presence of hypotension and increased odds of mortality.
  
  
  CONCLUSIONS
  The included studies suggest improved neurologic outcomes are associated with higher blood pressures in patients after cardiac arrest. This study highlights a need for further research to define the optimal management of blood pressure in this population.
authors.affiliation: Department of Medicine, Division of Critical Care Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Tahara D
authors.initials: TD
authors.lastname: Bhate
authors.affiliation: Department of Medicine, Division of Critical Care Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Braedon
authors.initials: B
authors.lastname: McDonald
authors.affiliation: Department of Medicine, Division of Critical Care Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Mypinder S
authors.initials: MS
authors.lastname: Sekhon
authors.affiliation: Department of Medicine, Division of Critical Care Medicine, University of British Columbia, Vancouver, BC, Canada; Department of Anesthesia, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada; Centre for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada. Electronic address: donald.griesdale@vch.ca.
authors.forename: Donald E G
authors.initials: DE
authors.lastname: Griesdale
mesh_terms: D001794:Blood Pressure; D006323:Heart Arrest / Q000150:complications* / Q000503:physiopathology*; D006801:Humans; D020925:Hypoxia-Ischemia, Brain / Q000209:etiology*
keywords: Blood pressure; Cardiac arrest; Hypoxaemic–ischaemic brain injury; Neurologic outcomes