title: [Neuropsychological dysfunction after cardiac surgery: Cerebral saturation and bispectral index: A longitudinal study].
abstract: BACKGROUND
  Neuropsychological dysfunction is a major cause of morbidity and mortality after cardiac surgery.
  
  
  OBJECTIVE
  To evaluate if intraoperative cerebral desaturation and depth of anesthesia measured by bispectral index are related to postoperative cognitive dysfunction in cardiac surgery.
  
  
  METHODS
  Prospective study in patients undergoing elective cardiac surgery with cardiopulmonary bypass. A comprehensive neuropsychological assessment was applied preoperatively and 3 months after surgery. Postoperative dysfunction was defined as a decrease of at least one standard deviation in two or more neuropsychological tests. Cerebral oxygenation and bispectral index were continuously recorded and corrected throughout surgery. Cerebral oxygenation data were analyzed by the mean value and at three thresholds: 50%, 40% and < 25% of the basal value. Bispectral index was analyzed at threshold of 45.
  
  
  RESULTS
  Fifty-six patients were initially enrolled and 48 completed the study. Nine of these (18.8 %) presented postoperative cognitive dysfunction. Mean cerebral saturation and bispectral index data were not different among the patients with or without cognitive dysfunction. There was no association between cerebral desaturation and bispectral index with changes in neurocognitive tests or with length of stay in the intensive care unit. A significant but weak correlation was found between baseline Ray-neurocognitive score and intensive care unit stay (rho = -0.46; P = 0.001).
  
  
  CONCLUSIONS
  We did not find a significant association between cerebral desaturation and depth of anesthesia with postoperative cognitive decline in this population of patients.
authors.affiliation: Hospital Clínico y Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Víctor M
authors.initials: VM
authors.lastname: Parra
authors.forename: Marc
authors.initials: M
authors.lastname: Sadurní
authors.forename: Marta
authors.initials: M
authors.lastname: Doñate
authors.forename: Irene
authors.initials: I
authors.lastname: Rovira
authors.forename: Carmen
authors.initials: C
authors.lastname: Roux
authors.forename: José
authors.initials: J
authors.lastname: Ríos
authors.forename: Teresa
authors.initials: T
authors.lastname: Boget
authors.forename: Guillermina
authors.initials: G
authors.lastname: Fita
mesh_terms: D000368:Aged; D000758:Anesthesia / Q000009:adverse effects*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D004569:Electroencephalography; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010101:Oxygen Consumption / Q000502:physiology*; D011183:Postoperative Complications / Q000209:etiology