title: Predisposing and precipitating factors of delirium after cardiac surgery: a prospective observational cohort study.
abstract: OBJECTIVE
  To comprehensively assess pre-, intra-, and postoperative delirium risk factors as potential targets for intervention.
  
  
  BACKGROUND
  Delirium after cardiac surgery is associated with longer intensive care unit (ICU) stay, and poorer functional and cognitive outcomes. Reports on delirium risk factors so far did not cover the full range of patients' presurgical conditions, intraoperative factors, and postoperative course.
  
  
  METHODS
  After written informed consent, 221 consecutive patients ≥ 50 years scheduled for cardiac surgery were assessed for preoperative cognitive performance, and functional and physical status. Clinical and biochemical data were systematically recorded perioperatively.
  
  
  RESULTS
  Of the 215 patients remaining for analysis, 31% developed delirium in the intensive care unit. Using logistic regression models, older age [73.3 (71.2-75.4) vs 68.5 (67.0-70.0); P = 0.016], higher Charlson's comorbidity index [3.0 (1.5-4.0) vs 2.0 (1.0-3.0) points; P = 0.009], lower Mini-Mental State Examination (MMSE) score (MMSE, [27 (23-29) vs 28 (27-30) points; P = 0.021], length of cardiopulmonary bypass (CPB) [CPB; 133 (112-163) vs 119 (99-143) min; P = 0.004], and systemic inflammatory response syndrome in the intensive care unit [25 (36.2%) vs 13 (8.9%); P = 0.001] were independently associated with delirium. Combining age, MMSE score, Charlson's comorbidity index, and length of CPB in a regression equation allowed for a prediction of postoperative delirium with a sensitivity of 71.19% and a specificity of 76.26% (receiver operating analysis, area under the curve: 0.791; 95% confidence interval: 0.727-0.845).
  
  
  CONCLUSIONS
  Further research will evaluate if modification of these risk factors prevents delirium and improves outcomes.
authors: Klinik für Anästhesiologie & Operative Intensivmedizin, Universitätsklinikum der Rheinischen Friedrich-Wilhelms Universität Bonn, Germany. u.guenther@uni-bonn.de
authors: Ulf
authors: U
authors: Guenther
authors: Nils
authors: N
authors: Theuerkauf
authors: Ingo
authors: I
authors: Frommann
authors: Kathrin
authors: K
authors: Brimmers
authors: Ramy
authors: R
authors: Malik
authors: Sangar
authors: S
authors: Stori
authors: Mona
authors: M
authors: Scheidemann
authors: Christian
authors: C
authors: Putensen
authors: Julius
authors: J
authors: Popp
mesh_terms: D000367:Age Factors; D000368:Aged; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D016009:Chi-Square Distribution; D003072:Cognition Disorders / Q000150:complications; D015897:Comorbidity; D003693:Delirium / Q000209:etiology*; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay / Q000706:statistics & numerical data; D016015:Logistic Models; D008297:Male; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012372:ROC Curve; D012307:Risk Factors; D012680:Sensitivity and Specificity; D018746:Systemic Inflammatory Response Syndrome / Q000150:complications; D013997:Time Factors