title: Pharmacological risk factors for delirium after cardiac surgery: a review.
abstract: OBJECTIVE
  The objective of this review is to evaluate the literature on medications associated with delirium after cardiac surgery and potential prophylactic agents for preventing it.
  
  
  METHODS
  Articles were searched in MEDLINE, Cumulative Index to Nursing and Allied Health, and EMBASE with the MeSH headings: delirium, cardiac surgical procedures, and risk factors, and the keywords: delirium, cardiac surgery, risk factors, and drugs. Principle inclusion criteria include having patient samples receiving cardiac procedures on cardiopulmonary bypass, and using DSM-IV-TR criteria or a standardized tool for the diagnosis of delirium.
  
  
  RESULTS
  Fifteen studies were reviewed. Two single drugs (intraoperative fentanyl and ketamine), and two classes of drugs (preoperative antipsychotics and postoperative inotropes) were identified in the literature as being independently associated with delirium after cardiac surgery. Another seven classes of drugs (preoperative antihypertensives, anticholinergics, antidepressants, benzodiazepines, opioids, and statins, and postoperative opioids) and three single drugs (intraoperative diazepam, and postoperative dexmedetomidine and rivastigmine) have mixed findings. One drug (risperidone) has been shown to prevent delirium when taken immediately upon awakening from cardiac surgery. None of these findings was replicated in the studies reviewed.
  
  
  CONCLUSIONS
  These studies have shown that drugs taken perioperatively by cardiac surgery patients need to be considered in delirium risk management strategies. While medications with direct neurological actions are clearly important, this review has shown that specific cardiovascular drugs may also require attention. Future studies that are methodologically consistent are required to further validate these findings and improve their utility.
authors: Department of Anesthesiology, Pharmacology & Therapeutics, The University of British Columbia, 2176 Health Sciences Mall, Vancouver, B.C., Canada, V6T 1Z3.
authors: Lurdes
authors: L
authors: Tse
authors: Stephan Kw
authors: SK
authors: Schwarz
authors: John B
authors: JB
authors: Bowering
authors: Randell L
authors: RL
authors: Moore
authors: Kyle D
authors: KD
authors: Burns
authors: Carole M
authors: CM
authors: Richford
authors: Jill A
authors: JA
authors: Osborn
authors: Alasdair M
authors: AM
authors: Barr
keywords: Cardiac surgery; delirium; drugs; medications; prevent; risk factors.