Meta-analysis of factors which influence delirium following cardiac surgery

Abstract Background: The aim of this study is to determine the risk factors of delirium after cardiac surgery. Methods: A systematic literature search of MEDLINE, EMBASE, the Cochrane Library, and Science Citation Index limited to 2008 to 2011 and review of studies was conducted. Eligible studies were of randomized controlled trials or cohort studies, using delirium assessment tool, reporting at least one risk factor associated with delirium, and available to full text. Results: The search identified 106 potentially relevant publications; only 25 met selection criteria. Our systematic review revealed 33 risk factors: 17 predisposing and 16 precipitating factors for delirium after elective cardiac surgery. The most established predisposing risk factors were age, depression, and history of stroke, cognitive impairment, diabetes mellitus, and atrial fibrillation. The most established precipitating risk factors were duration of surgery, prolonged intubation, surgery type, red blood cell transfusion, elevation of inflammatory markers and plasma cortisol level, and postoperative complications. Moreover, sedation with dexmedetomidine may significantly predict the absence of postoperative delirium. Conclusions: Postoperative delirium is related to several risk factors following cardiac surgery. Sedation with dexmedetomidine and fast‐track weaning protocols may decrease the incidence of delirium in cardiac surgical patients. (J Card Surg 2012;27:481‐492)