Purpose: 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.
Source: 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.
Principal Findings: 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.
Conclusion: 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.