title: Cortisol levels and neuropsychiatric diagnosis as markers of postoperative delirium: a prospective cohort study.
abstract: BACKGROUND
  The pathophysiology of delirium after cardiac surgery is largely unknown. The purpose of this study was to investigate whether increased concentration of preoperative and postoperative plasma cortisol predicts the development of delirium after coronary artery bypass graft surgery. A second aim was to assess whether the association between cortisol and delirium is stress related or mediated by other pathologies, such as major depressive disorder (MDD) or cognitive impairment.
  
  
  METHODS
  The patients were examined 1 day preoperatively with the Mini International Neuropsychiatric Interview and the Montreal Cognitive Assessment and the Trail Making Test to screen for depression and for cognitive impairment, respectively. Blood samples for cortisol levels were collected both preoperatively and postoperatively. The Confusion Assessment Method for the Intensive Care Unit was used within the first 5 days postoperatively to screen for a diagnosis of delirium.
  
  
  RESULTS
  Postoperative delirium developed in 36% (41 of 113) of participants. Multivariate logistic regression analysis revealed two groups independently associated with an increased risk of developing delirium: those with preoperatively raised cortisol levels; and those with a preoperative diagnosis of MDD associated with raised levels of cortisol postoperatively. According to receiver operating characteristic analysis, the most optimal cutoff values of the preoperative and postoperative cortisol concentration that predict the development of delirium were 353.55 nmol/l and 994.10 nmol/l, respectively.
  
  
  CONCLUSIONS
  Raised perioperative plasma cortisol concentrations are associated with delirium after coronary artery bypass graft surgery. This may be an important pathophysiological consideration in the increased risk of postoperative delirium seen in patients with a preoperative diagnosis of MDD.
authors: Jakub
authors: J
authors: Kazmierski
authors: Andrzej
authors: A
authors: Banys
authors: Joanna
authors: J
authors: Latek
authors: Julius
authors: J
authors: Bourke
authors: Ryszard
authors: R
authors: Jaszewski
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003693:Delirium / Q000097:blood* / Q000175:diagnosis / Q000523:psychology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood* / Q000175:diagnosis / Q000523:psychology*; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales
chemical_list: D015415:Biomarkers; D006854:Hydrocortisone