The Effect of Dexmedetomidine Infusion on Post-operative Cognitive Function and Oxidative Stress in Patients Undergo Cardiopulmonary Bypass Machine Facilitated Elective Cardiac Surgery

简要总结

详细描述

After the patients were enrolled in the study, they were allocated into Dexmedetomidine group or control group by computer-based randomization. Patients, surgeons, anesthesiologists and researchers who performed the cognitive test were all blinded to the study groups. General anesthesia was induced with intravenously midazolam 0.1-0.2 mg/kg and fentanyl 5-10 mcg/kg or Thiopental 3-5 mg/kg or Propofol 2 mg/kg. Patients were intubated with pancuronium 1 mg/kg or rocuronium 0.6-1 mg/kg. Anesthesia was maintained with nitrous oxide in oxygen, isoflurane, fentanyl, and pancuronium or rocuronium as required. Standard monitoring was provided including an indwelling radial artery catheter and central venous catheter. Bispectral index (BIS) monitoring was applied and maintained between 40-60 through the operation. Cerebral oximetry was monitored both sides of the brain by non-invasive oximeters at forehead area and the data were recorded. After skin incision, the Dexmedetomidine group received a loading dose of 0.5 mcg/kg of Dexmedetomidine in 20 minutes followed by a continuous IV infusion at 0.4 mcg/kg/hr until the end of operation.The control group received a loading dose and continuous IV infusion of normal saline at the same rate. During the cardiopulmonary bypass, mean arterial pressure was maintained at 60-80 mmHg or 20% from baseline. If hypertension was detected, Nicardipine 0.2 mg was given intravenously. Ephedrine 6 mg or norepinephrine 4 mcg were given within 5 minutes and repeated every 5 minutes if hypotension was presented. Atropine 0.6 mg was administered for bradycardia (heart rate less than 50 beats per minute). After the operation, patients were transferred to Cardio-thoracic intensive care unit and received standard postoperative cardiac surgery care. 2 neuropsychological tests were used to evaluate patients' cognitive function; Montreal Cognitive Assessment (MoCA) and Short blessed test (SBT). These tests were chosen by King Chulalongkorn Memorial Hospital's psychiatrist based on previous studies and the statement consensus on assessment of neurobehavioral outcomes after cardiac surgery published in 1995. All patients were evaluated their cognitive function for 3 points of time, 1st time was at preoperative period (T1), 2nd time was at 48 hours postoperatively (T2) and the last one was at 7 days postoperatively or the day at discharge from the hospital (T3). POCD was defined as a decline of 1 standard deviation (1SD) of baseline score in any test. Blood samples were taken through the radial artery catheter, and sampling times were chosen as follows: before the induction of anaesthesia (T0); after separated from CPB (T1); arrival at intensive care unit (ICU) (T2); 24 hr after surgery (T3). Plasma Tissue Necrotic Factor-Alpha (TNF-α), Interleukin-6 (IL-6) and Interleukin-10 (IL-10) levels were measured by Magnetic Luminex Performance Assay. High sensitivity C-reactive protein (CRP) level were also measured by nephelometry.

主要结局

次要结局

• Number of Participants With Postoperative Complications(7 days)
• Hospital Stay in Days(30 days)
• ICU Stay in Hours(7 days)