title: Influence of intraoperative cerebral oximetry monitoring on neurocognitive function after coronary artery bypass surgery: a randomized, prospective study.
abstract: OBJECTIVE
  Postoperative cognitive decline is common after cardiac surgery, but it is often unrecognized at the time of hospital discharge. However, it has a great impact on patient's quality of life. Cerebral oximetry with the INVOS (IN Vivo Optical Spectroscopy) system provides the possibility of non-invasive, continuous measurement of regional cerebral oxygen saturation (rSO2), which can improve patients' outcome. The aim of this study was to examine whether cerebral oximetry can decrease the incidence of cognitive decline after coronary artery bypass grafting.
  
  
  METHODS
  We have performed a prospective, randomized study with 200 patients enrolled. Patients were divided into INVOS interventional group and CONTROL group without monitoring of cerebral oximetry. A standardized interventional protocol was performed in the INVOS group to maintain rSO2 above 80% of the patient's baseline value or above 50% of the absolute value. Cognitive evaluation was performed in all patients before and 7 days after surgery. Logistic regression was used to reveal predictors of cognitive decline.
  
  
  RESULTS
  The incidence of cognitive decline 7 days after surgery was significantly lower (P = 0.002) in the INVOS interventional group (28%) than in the CONTROL group (52%). Intraoperative use of INVOS monitoring was associated with lower incidence of cognitive decline (odds ratio 0.21). In addition, predictors of cognitive decline revealed by multivariate logistic regression were older age, higher EuroSCORE and SAPS II (Simplified Acute Physiology Score) values, lower educational level and persistence of preoperative atrial fibrillation. Patients with prolonged rSO2 desaturation, defined as rSO2 area under the curve (AUC) of more than 150 min% for desaturation below 20% of baseline or AUC of more than 50 min% for desaturation below 50% absolute value, had an increased risk of cognitive decline.
  
  
  CONCLUSIONS
  Postoperative cognitive outcome was significantly better in patients with intraoperative cerebral oximetry monitoring. Prolonged rSO2 desaturation is a predictor of cognitive decline and has to be avoided.
authors.affiliation: Department of Anesthesiology, Reanimatology and Intensive Care Medicine, University Hospital Center Zagreb, Zagreb, Croatia zcolak2000@yahoo.com.
authors.forename: Zeljko
authors.initials: Z
authors.lastname: Colak
authors.affiliation: Department of Cardiac Surgery, University Hospital Center Zagreb, Zagreb, Croatia.
authors.forename: Marko
authors.initials: M
authors.lastname: Borojevic
authors.affiliation: Psychiatric Hospital Sv. Ivan, Zagreb, Croatia.
authors.forename: Anamarija
authors.initials: A
authors.lastname: Bogovic
authors.affiliation: Department of Anesthesiology, Reanimatology and Intensive Care Medicine, University Hospital Center Zagreb, Zagreb, Croatia.
authors.forename: Visnja
authors.initials: V
authors.lastname: Ivancan
authors.affiliation: Department of Cardiac Surgery, University Hospital Center Zagreb, Zagreb, Croatia.
authors.forename: Bojan
authors.initials: B
authors.lastname: Biocina
authors.affiliation: Department of Anesthesiology, Reanimatology and Intensive Care Medicine, University Hospital Center Zagreb, Zagreb, Croatia.
authors.forename: Visnja
authors.initials: V
authors.lastname: Majeric-Kogler
mesh_terms: D000368:Aged; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003072:Cognition Disorders / Q000209:etiology*; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000097:blood*
chemical_list: D010100:Oxygen
keywords: Cardiopulmonary bypass; Cerebral oximetry; Cognitive dysfunction