title: Cognitive and functional predictors and sequelae of postoperative delirium in elderly patients undergoing elective joint arthroplasty.
abstract: BACKGROUND
  Postoperative delirium (POD) is common in the elderly and associated with adverse outcomes. The cognitive and functional sequelae of POD in elective surgical patients are not known. We sought to determine whether (1) lower scores on sensitive neurocognitive tests are an independent risk factor for POD in elderly surgical patients, and (2) POD predicts cognitive and functional decline 3 months postoperatively.
  
  
  METHODS
  We conducted a prospective, cohort study on patients ≥65 years old undergoing total hip or knee arthroplasty. Participants underwent preoperative neurocognitive and functional testing. POD was diagnosed using the Confusion Assessment Method. Patients who developed POD and matched controls underwent repeat neurocognitive and functional testing 3 months after surgery.
  
  
  RESULTS
  Four hundred eighteen patients met entry criteria, and 42 (10%) developed POD. There were no differences in baseline Mini-Mental State Examination scores, alcohol abuse, depression, and verbal intelligence between groups. Independent predictors of POD included age, history of psychiatric illness, decreased functional status, and decreased verbal memory. For all tests, changes from before to 3 months after surgery were similar between those patients with POD and matched controls.
  
  
  CONCLUSIONS
  Subtly reduced preoperative neurocognitive and functional status predict POD. However, in the small group that developed POD, there was no evidence of cognitive and functional decline 3 months after surgery. POD is associated with decreased preoperative cognitive reserve but, in elderly elective surgical patients, may be without adverse cognitive or functional sequelae 3 months postoperatively.
authors.affiliation: Department of Anesthesiology, Mayo Clinic, Charlton 1-145, 200 First St., SW, Rochester, MN 55905, USA. jankowski.christopher@mayo.edu
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Jankowski
authors.forename: Max R
authors.initials: MR
authors.lastname: Trenerry
authors.forename: David J
authors.initials: DJ
authors.lastname: Cook
authors.forename: Shonie L
authors.initials: SL
authors.lastname: Buenvenida
authors.forename: Susanna R
authors.initials: SR
authors.lastname: Stevens
authors.forename: Darrell R
authors.initials: DR
authors.lastname: Schroeder
authors.forename: David O
authors.initials: DO
authors.lastname: Warner
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000523:psychology; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000523:psychology; D003071:Cognition; D003072:Cognition Disorders / Q000150:complications* / Q000175:diagnosis / Q000523:psychology; D003693:Delirium / Q000175:diagnosis / Q000209:etiology* / Q000523:psychology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008910:Minnesota; D009483:Neuropsychological Tests; D016017:Odds Ratio; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome