Postoperative delirium following transcatheter aortic valve implantation: a historical cohort study.

PURPOSE: Transcatheter aortic valve implantation (TAVI) techniques show favourable survival outcomes in high-risk patients, but the incidence of postoperative delirium is unknown. We conducted a historical cohort study to compare postoperative delirium in retrograde transfemoral (TF) versus anterograde transapical (TA) TAVI procedures. We also sought to identify independent predictors of delirium following TAVI. METHODS: We performed a retrospective chart review on all patients who underwent TF (n = 77) or TA (n = 45) TAVI during 2008 and 2009 at St. Paul's Hospital (Vancouver, BC, Canada), the pioneering centre for these procedures. The primary outcome was a documented physician diagnosis of delirium. Abstracted data included information on demographics, medical history, surgical procedure, anesthesia, and postoperative care. We employed a multivariable logistic regression to identify independent predictors of delirium. RESULTS: Delirium occurred in 12% of TF patients vs 53% of TA patients (P < 0.001). Preoperatively, the groups differed significantly in the rates of hypertension, pulmonary hypertension, dyslipidemia, peripheral vascular disease, congestive heart failure, previous myocardial infarction, and memory impairment. Differences in anesthetic management were also observed between the TF vs TA groups regarding inhalational anesthetics, opioids, neuromuscular blockers, antihemorrhagic drugs, and antibiotics. Independent predictors for delirium after TAVI included coronary artery disease (odds ratio [OR] 12.7; 95% confidence interval [CI] 1.0 to 154.9), cognitive impairment (OR 6.5; 95% CI 1.8 to 23.2), and cardiac arrhythmia (OR 3.5; 95% CI 1.1 to 11.6). Compared to the TF approach, TA-TAVI independently increased the risk of delirium (OR 13.8; 95% CI 3.3 to 59.0). CONCLUSIONS: Patients undergoing TA-TAVI had a markedly increased incidence of postoperative delirium compared with patients undergoing TF-TAVI.

Pharmacological risk factors for delirium after cardiac surgery: a review.

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.