title: Investigation of factors relating to neuropsychological change following cardiac surgery.
abstract: BACKGROUND
  An analysis of neuropsychological impairment following cardiopulmonary bypass was performed in 55 patients undergoing elective coronary artery bypass grafting.
  
  
  METHODS
  Neurocognitive function was measured preoperatively using the MicroCog: Assessment of Cognitive Functioning computer-based testing tool. Testing was repeated in the postoperative period immediately prior to discharge from hospital. Analysis of significant score decline was performed using the standardised regression-based technique. A patient was classified as overall impaired when > or = 20% of test scores were significantly impaired. The proposed marker of neurological damage S-100beta was also used. Prothrombin Fragment 1+2 (F1+2) was measured as a marker of thrombin development to test the hypothesis that excessive haemostatic activation may lead to thromboembolic damage to the brain.
  
  
  CONCLUSIONS
  32.7% of patients were classified as significantly impaired. No relationship was detected between F1+2 and any neuropsychological test score; however, the study was limited due to small sample size. F1+2 levels were higher in patients undergoing prolonged bypass times. Neuropsychological decline was significantly correlated with patient age, suggesting a degree of caution is warranted when operating on an elderly cohort. An unexpected relationship was detected between higher heparin concentrations and increased risk of neuropsychological impairment; however, this requires re-evaluation.
authors.affiliation: Research Concentration in Biological and Medical Sciences, School of Life Sciences, Queensland University of Technology, Brisbane, Australia. p.raymond@optusnet.com.au
authors.forename: Paul D
authors.initials: PD
authors.lastname: Raymond
authors.forename: Michael
authors.initials: M
authors.lastname: Radel
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Ray
authors.forename: Anton D
authors.initials: AD
authors.lastname: Hinton-Bayre
authors.forename: Neville A
authors.initials: NA
authors.lastname: Marsh
mesh_terms: D000367:Age Factors; D000368:Aged; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D017558:Elective Surgical Procedures; D005260:Female; D006493:Heparin / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000097:blood; D011184:Postoperative Period; D011516:Prothrombin; D012307:Risk Factors
chemical_list: D010446:Peptide Fragments; C045879:prothrombin fragment 1.2; D011516:Prothrombin; D006493:Heparin