title: Incidence and risk factors of postoperative delirium in elderly patients who underwent laparoscopic surgery for colorectal cancer.
abstract: BACKGROUND
  The reported incidence of postoperative delirium (POD) in elderly patients ranges from 6 to 53 %. Several preoperative and operative factors have been reported as risk factors of POD.
  
  
  OBJECTIVE
  The aim of this study was to determine the incidence of and risk factors for POD in patients with colorectal cancer who had undergone laparoscopic colorectal resection.
  
  
  METHODS
  A total of 311 consecutive patients aged 75 years and older who underwent laparoscopic surgery for colorectal cancer at our department from January 2008 to December 2013 were classified as delirious group (n = 44) and nondelirious group (n = 267). Short-term outcomes and risk factors for POD were analyzed.
  
  
  RESULTS
  POD was diagnosed in 14.1 % of elderly patients with colorectal cancer. Univariate analysis showed that older age, high American Society of Anesthesiology (ASA) score, performance status >2, low prognostic nutrition index (PNI), past history of delirium or dementia, operative approach, Organ/Space SSI, and cardiac or pulmonary disease were significantly associated with POD. Multivariate logistic regression analysis identified older age, past history of delirium or dementia, operative approach, and Organ/Space SSI as four independent risk factors for POD.
  
  
  CONCLUSIONS
  Our results suggest that the risk of POD is associated with older age, past history of delirium or dementia, operative approach, Organ/Space SSI.
authors.affiliation: Department of Surgery, Osaka Police Hospital, 10-31, Kitayama-cho, Tennoji-ku, Osaka City, Osaka, 543-0035, Japan. mtei@live.jp.
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Tei
authors.affiliation: Department of Surgery, Osaka Police Hospital, 10-31, Kitayama-cho, Tennoji-ku, Osaka City, Osaka, 543-0035, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Wakasugi
authors.affiliation: Department of Surgery, Osaka Police Hospital, 10-31, Kitayama-cho, Tennoji-ku, Osaka City, Osaka, 543-0035, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kishi
authors.affiliation: Department of Surgery, Osaka Police Hospital, 10-31, Kitayama-cho, Tennoji-ku, Osaka City, Osaka, 543-0035, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tanemura
authors.affiliation: Department of Surgery, Osaka Police Hospital, 10-31, Kitayama-cho, Tennoji-ku, Osaka City, Osaka, 543-0035, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Akamatsu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000601:surgery*; D003693:Delirium / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D015994:Incidence; D010535:Laparoscopy / Q000009:adverse effects*; D008297:Male; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000209:etiology*; D011300:Preoperative Care; D012307:Risk Factors
keywords: Colorectal cancer; Elderly patient; Postoperative delirium; Single-incision laparoscopic surgery; Single-port surgery