title: Preoperative exercise capacity is associated with the prevalence of postoperative delirium in elective cardiac surgery.
abstract: BACKGROUND
  Postoperative delirium (POD) is a critical complication that is closely associated with mortality and major morbidity in elective cardiac surgery. The identification of patients at risk for POD is crucial but has not been fully explored.
  
  
  OBJECTIVE
  The aim of this study was to determine the predictive value of the assessment of preoperative exercise capacity for POD.
  
  
  METHODS
  We enrolled 313 consecutive patients (mean age, 68.6 ± 14.8 years) undergoing elective cardiac surgery. We measured physical functions such as the 6-minute walking distance (6MWD) and Timed Up-and-Go test (TUG) before surgery. The assessment of delirium was conducted every 8 h from the day of surgery to 5 days after surgery using the Intensive Care Delirium Screening Checklist.
  
  
  RESULTS
  POD occurred in 46 patients (14.6%). Age, 6MWD, TUG, serum hemoglobin, estimated glomerular filtration rate, and length of intensive care unit stay were significantly different based on the presence or absence of POD (p < 0.05 for each). After multivariate analysis, 6MWD remained a statistically significant indicator for developing POD (OR 0.98; p = 0.02). The cut-off value of 6MWD for predicting POD was 345 m (AUC = 0.75; p = 0.001).
  
  
  CONCLUSIONS
  Poor exercise capacity was found to be an independent predictor of POD following elective cardiac surgery. This finding suggests the importance of preoperative functional evaluation in the prevention and management of POD in cardiac surgery patients.
authors.affiliation: Division of Rehabilitation Medicine, Kobe University Hospital, Kobe, Hyogo, 654-0142, Japan.|Graduate School of Health Sciences, Kobe University, 7-10-2 Tomogaoka, Suma-ku, Kobe, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Ogawa
authors.affiliation: Graduate School of Health Sciences, Kobe University, 7-10-2 Tomogaoka, Suma-ku, Kobe, Japan. izawapk@harbor.kobe-u.ac.jp.
authors.forename: Kazuhiro P
authors.initials: KP
authors.lastname: Izawa
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Seimi
authors.initials: S
authors.lastname: Satomi-Kobayashi
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Aki
authors.initials: A
authors.lastname: Kitamura
authors.affiliation: Division of Rehabilitation Medicine, Kobe University Hospital, Kobe, Hyogo, 654-0142, Japan.|Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Tsuboi
authors.affiliation: Division of Rehabilitation Medicine, Kobe University Hospital, Kobe, Hyogo, 654-0142, Japan.
authors.forename: Kodai
authors.initials: K
authors.lastname: Komaki
authors.affiliation: Graduate School of Health Sciences, Kobe University, 7-10-2 Tomogaoka, Suma-ku, Kobe, Japan.
authors.forename: Rei
authors.initials: R
authors.lastname: Ono
authors.affiliation: Division of Rehabilitation Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoshitada
authors.initials: Y
authors.lastname: Sakai
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Okita
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003422:Critical Care; D017558:Elective Surgical Procedures / Q000009:adverse effects; D000071257:Emergence Delirium / Q000517:prevention & control*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment
keywords: Cardiac surgery; Exercise capacity; Postoperative delirium; Preoperative assessment; Six-minute walking distance