title: Impaired olfaction and risk of delirium or cognitive decline after cardiac surgery.
abstract: OBJECTIVE
  To determine the prevalence of impaired olfaction in individuals presenting for cardiac surgery and the independent association between impaired olfaction and postoperative delirium and cognitive decline.
  
  
  METHODS
  Nested prospective cohort study.
  
  
  METHODS
  Academic hospital.
  
  
  METHODS
  Individuals undergoing coronary artery bypass, valve surgery, or both (n = 165).
  
  
  METHODS
  Olfaction was measured using the Brief Smell Identification Test, with impaired olfaction defined as an olfactory score below the fifth percentile of normative data. Delirium was assessed using a validated chart review method. Cognitive performance was assessed using a neuropsychological testing battery at baseline and 4 to 6 weeks after surgery.
  
  
  RESULTS
  Impaired olfaction was identified in 54 of 165 participants (33%) before surgery. Impaired olfaction was associated with greater adjusted risk of postoperative delirium (relative risk = 1.90, 95% confidence interval = 1.17-3.09, P = .009). There was no association between impaired olfaction and change in composite cognitive score in the overall study population.
  
  
  CONCLUSIONS
  Impaired olfaction is prevalent in individuals undergoing cardiac surgery and is associated with greater adjusted risk of postoperative delirium but not cognitive decline. Impaired olfaction may identify unrecognized vulnerability to postoperative delirium in individuals undergoing cardiac surgery.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Brown
authors.forename: Candice
authors.initials: C
authors.lastname: Morrissey
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ono
authors.forename: Gayane
authors.initials: G
authors.lastname: Yenokyan
authors.forename: Ola A
authors.initials: OA
authors.lastname: Selnes
authors.forename: Jeremy
authors.initials: J
authors.lastname: Walston
authors.forename: Laura
authors.initials: L
authors.lastname: Max
authors.forename: Andrew
authors.initials: A
authors.lastname: LaFlam
authors.forename: Karin
authors.initials: K
authors.lastname: Neufeld
authors.forename: Rebecca F
authors.initials: RF
authors.lastname: Gottesman
authors.forename: Charles W
authors.initials: CW
authors.lastname: Hogue
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D006348:Cardiac Surgical Procedures; D001026:Coronary Artery Bypass; D003693:Delirium / Q000453:epidemiology; D006349:Heart Valve Diseases / Q000601:surgery; D009483:Neuropsychological Tests; D000857:Olfaction Disorders / Q000453:epidemiology; D011183:Postoperative Complications / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors
keywords: cognition disorders; delirium; olfaction disorders