title: Delirium after cardiac surgery: A pilot study from a single tertiary referral center.
abstract: BACKGROUND
  Advances in cardiac surgery has shifted paradigm of management to perioperative psychological illnesses. Delirium is a state of altered consciousness with easy distraction of thoughts. The pathophysiology of this complication is not clear, but identification of risk factors is important for positive postoperative outcomes. The goal of the present study was to prospectively identify the incidence, motoric subtypes, and risk factors associated with development of delirium in cardiac surgical patients admitted to postoperative cardiac intensive care, using a validated delirium monitoring instrument.
  
  
  METHODS
  This is a prospective, observational study. This study included 120 patients of age 18-80 years, admitted to undergo cardiac surgery after applying inclusion and exclusion criteria. Specific preoperative, intraoperative, and postoperative data for possible risk factors were obtained. Once in a day, assessment of delirium was done. Continuous variables were measured as mean ± standard deviation, whereas categorical variables were described as proportions. Differences between groups were analyzed using Student's t-test, Mann-Whitney U-test, or Chi-square test. Variables with a P < 0.1 were then used to develop a predictive model using stepwise logistic regression with bootstrapping.
  
  
  RESULTS
  Delirium was seen in 17.5% patients. The majority of cases were of hypoactive delirium type (85.72%). Multiple risk factors were found to be associated with delirium, and when logistic regression with bootstrapping applied to these risk factors, five independent variables were detected. History of hypertension (relative risk [RR] =6.7857, P = 0.0003), carotid artery disease (RR = 4.5000, P < 0.0001) in the form of stroke or hemorrhage, noninvasive ventilation (NIV) use (RR = 5.0446, P < 0.0001), Intensive Care Unit (ICU) stay more than 10 days (RR = 3.1630, P = 0.0021), and poor postoperative pain control (RR = 2.4958, P = 0.0063) was associated with postcardiac surgical delirium.
  
  
  CONCLUSIONS
  Patients who developed delirium had systemic disease in the form of hypertension and cerebrovascular disease. Delirium was seen in patients who had higher postoperative pain scores, longer ICU stay, and NIV use. This study can be used to develop a predictive tool for diagnosing postcardiac surgical delirium.
authors.affiliation: Department of Anaesthesia, Postgraduate Institute for Medical Education and Research, Chandigarh, India.
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Kumar
authors.affiliation: Department of Anaesthesia, Postgraduate Institute for Medical Education and Research, Chandigarh, India.
authors.forename: Aveek
authors.initials: A
authors.lastname: Jayant
authors.affiliation: Department of Anaesthesia, Postgraduate Institute for Medical Education and Research, Chandigarh, India.
authors.forename: V K
authors.initials: VK
authors.lastname: Arya
authors.affiliation: Department of Anaesthesia, Postgraduate Institute for Medical Education and Research, Chandigarh, India.
authors.forename: Rohan
authors.initials: R
authors.lastname: Magoon
authors.affiliation: Department of Anaesthesia, Postgraduate Institute for Medical Education and Research, Chandigarh, India.
authors.forename: Ridhima
authors.initials: R
authors.lastname: Sharma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003693:Delirium / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D010865:Pilot Projects; D011183:Postoperative Complications / Q000175:diagnosis*; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D062606:Tertiary Care Centers; D055815:Young Adult