title: Risk factors of delirium after cardiac surgery: a systematic review.
abstract: BACKGROUND
  Delirium or acute confusion is a temporary mental disorder that occurs frequently among hospitalized elderly patients, but also in younger patients a delirium can develop. Patients who undergo cardiac surgery have an increased risk of developing delirium that is associated with many negative consequences. Therefore, prevention of delirium is essential. Despite the high incidence of delirium, a paucity of data on risk factors for delirium exists.
  
  
  OBJECTIVE
  The aim of this study was to summarize the available information concerning these risk factors.
  
  
  METHODS
  A literature research was performed using the PubMed, Cinahl, and Cochrane Library databases and was limited to the last 10 years.
  
  
  RESULTS
  Our review revealed 27 risk factors; 12 predisposing and 15 precipitating factors for delirium after cardiac surgery. The most established predisposing risk factors were atrial fibrillation, cognitive impairment, depression, history of stroke, older age, and peripheral vascular disease. The most established precipitating risk factor was a red blood cell transfusion. An abnormal albumin level was reported as the most established precipitating risk factor among blood values tested. A low cardiac output and the use of an Intra Aortic Balloon Pump or inotropic medication seem to be the most relevant risk factors associated with a postoperative delirium.
  
  
  CONCLUSIONS
  A multifactorial risk model should be applied to identify patients at an increased risk of developing delirium following elective cardiac surgery. In these patients, if possible, preventative interventions can be taken and early recognition of delirium can be realized. This could potentially decrease the incidence of delirium and negative consequences caused by a postoperative delirium.
authors.affiliation: Department of Cardio Thoracic Surgery, Medisch Spectrum Twente, Haaksbergerstraat 55, 7500 KA Enschede, The Netherlands. s.koster@mst.nl
authors.forename: Sandra
authors.initials: S
authors.lastname: Koster
authors.forename: Ab G
authors.initials: AG
authors.lastname: Hensens
authors.forename: Marieke J
authors.initials: MJ
authors.lastname: Schuurmans
authors.forename: Job
authors.initials: J
authors.lastname: van der Palen
mesh_terms: D002318:Cardiovascular Diseases / Q000451:nursing / Q000601:surgery*; D003693:Delirium / Q000209:etiology* / Q000451:nursing; D006801:Humans; D011183:Postoperative Complications / Q000209:etiology* / Q000451:nursing; D012307:Risk Factors