title: The Impact of Delirium After Cardiac Surgical Procedures on Postoperative Resource Use.
abstract: BACKGROUND
  Delirium is a common complication after cardiac surgical procedures and is associated with increased morbidity and mortality. However, whether rigorously assessed postoperative delirium is associated with an increased length of stay in the intensive care unit (LOS-ICU), length of stay (LOS), and hospital charges is not clear.
  
  
  METHODS
  Patients (n = 66) undergoing coronary artery bypass or valve operations, or both, were enrolled in a nested cohort study. Rigorous delirium assessments were conducted using the Confusion Assessment Method. LOS-ICU and LOS were obtained from the medical record, and hospital charges were obtained from administrative data reported to the state. Because of the skewed distribution of outcome variables, outcomes were compared using rank-sum tests, as well as median regression incorporating propensity scores.
  
  
  RESULTS
  Patients who developed delirium (56%) versus no delirium (43%) had increased median LOS-ICU (75.6 hours [interquartile range (IQR): 43.6 to 136.8] vs. 29.7 hours [IQR: 21.7 to 46.0]; p = 0.002), increased median LOS (9 days [IQR: 6 to 16] vs. 7 days [IQR: 5 to 8]; p = 0.006), and increased median hospital charges ($51,805 [IQR: $44,041 to $80,238] vs. $41,576 [IQR: $35,748 to $43,660]; p = 0.002). In propensity score models adjusted for patient-related and surgical characteristics and complications, the results for LOS-ICU and cost remained highly significant, although the results for LOS were attenuated on the basis of the specific statistical model. Increased severity of delirium was associated with both increased LOS-ICU and increased charges in a dose-response manner.
  
  
  CONCLUSIONS
  Delirium after cardiac surgical procedures is independently associated with both increased LOS-ICU and higher hospital charges. Because delirium is potentially preventable, targeted delirium-prevention protocols for high-risk patients may represent an important strategy for quality improvement.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore. Electronic address: cbrownv@jhmi.edu.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Brown
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore.
authors.forename: Andrew
authors.initials: A
authors.lastname: Laflam
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore.
authors.forename: Laura
authors.initials: L
authors.lastname: Max
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore.
authors.forename: Daria
authors.initials: D
authors.lastname: Lymar
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore.
authors.forename: Karin J
authors.initials: KJ
authors.lastname: Neufeld
authors.affiliation: Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Jing
authors.initials: J
authors.lastname: Tian
authors.affiliation: Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Ashish S
authors.initials: AS
authors.lastname: Shah
authors.affiliation: Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore.
authors.forename: Glenn J
authors.initials: GJ
authors.lastname: Whitman
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore.
authors.forename: Charles W
authors.initials: CW
authors.lastname: Hogue
mesh_terms: D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003693:Delirium / Q000191:economics*; D005260:Female; D006295:Health Resources; D017722:Hospital Charges; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000191:economics*