title: Predictors of delirium after cardiac surgery delirium: effect of beating-heart (off-pump) surgery.
abstract: BACKGROUND
  Despite improved outcomes after cardiac operations, postoperative delirium remains a common complication that is associated with increased morbidity and prolonged hospital stay.
  
  
  METHODS
  Univariate and multivariate predictors of postoperative delirium were determined from prospectively gathered data on 16,184 patients undergoing cardiac operations with cardiopulmonary bypass (conventional, n = 14,342) and without cardiopulmonary bypass (beating-heart surgery, n = 1847) between April 1996 and August 2001. Delirium was defined as a transient mental syndrome of acute onset characterized by global impairment of cognitive functions, a reduced level of consciousness, attentional abnormalities, increased or decreased psychomotor activity, and a disordered sleep-wake cycle.
  
  
  RESULTS
  The overall prevalence of postoperative delirium was 8.4%. Of 49 selected patient-related risk factors and treatment variables, 35 were highly associated with postoperative delirium by univariate analysis. Stepwise logistic regression revealed the following variables as independent predictors of delirium: history of cerebrovascular disease, peripheral vascular disease, atrial fibrillation, diabetes mellitus, left ventricular ejection fraction of 30% or less, preoperative cardiogenic shock, urgent operation, intraoperative hemofiltration, operation time of 3 hours or more, and a high perioperative transfusion requirement. Two variables were identified as having a significant protective effect against postoperative delirium: beating-heart surgery and younger patient age.
  
  
  CONCLUSIONS
  Postoperative delirium is a common complication in cardiac operations. The increased use of beating-heart surgery without cardiopulmonary bypass may lead to a lower prevalence of this complication and thus improve patient outcomes.
authors.affiliation: Department of Cardiac Surgery, Heart Center, University of Leipzig, Germany. bucerj@medizin.uni-leipzig.de
authors.forename: Jan
authors.initials: J
authors.lastname: Bucerius
authors.forename: Jan F
authors.initials: JF
authors.lastname: Gummert
authors.forename: Michael A
authors.initials: MA
authors.lastname: Borger
authors.forename: Thomas
authors.initials: T
authors.lastname: Walther
authors.forename: Nicolas
authors.initials: N
authors.lastname: Doll
authors.forename: Volkmar
authors.initials: V
authors.lastname: Falk
authors.forename: Dierk V
authors.initials: DV
authors.lastname: Schmitt
authors.forename: Friedrich W
authors.initials: FW
authors.lastname: Mohr
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000379:methods*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects / Q000379:methods; D015331:Cohort Studies; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000379:methods; D003693:Delirium / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011183:Postoperative Complications / Q000175:diagnosis* / Q000453:epidemiology; D011237:Predictive Value of Tests; D015995:Prevalence; D011336:Probability; D011446:Prospective Studies; D017678:Sex Distribution; D016019:Survival Analysis