title: Randomized, double-blinded, placebo controlled study of neuroprotection with lidocaine in cardiac surgery.
abstract: OBJECTIVE
  Cognitive decline after cardiac surgery remains common and diminishes patients' quality of life. Based on experimental and clinical evidence, this study assessed the potential of intravenously administered lidocaine to reduce postoperative cognitive dysfunction after cardiac surgery using cardiopulmonary bypass.
  
  
  METHODS
  After IRB approval, 277 patients undergoing cardiac surgery were enrolled into this prospective, randomized, double-blinded placebo controlled clinical trial. Subjects were randomized to receive: (1) Lidocaine as a 1 mg/kg bolus followed by a continuous infusion through 48 hours postoperatively, or (2) Placebo bolus and infusion. Cognitive function was assessed preoperatively and again at 6 weeks and 1 year postoperatively. The effect of lidocaine on postoperative cognition was tested using multivariable regression modeling; P<0.05 was considered significant.
  
  
  RESULTS
  Among the 241 allocated subjects (Lidocaine: n=114; Placebo: n=127), the incidence of cognitive deficit in the lidocaine group was 45.5% versus 45.7% in the placebo group (P=0.97). Multivariable analysis revealed a significant interaction between treatment group and diabetes, such that diabetic subjects receiving lidocaine were more likely to suffer cognitive decline (P=0.004). Secondary analysis identified total lidocaine dose (mg/kg) as a significant predictor of cognitive decline and also revealed a protective effect of lower dose lidocaine in nondiabetic subjects.
  
  
  CONCLUSIONS
  Lidocaine administered during and after cardiac surgery does not reduce the high rate of postoperative cognitive dysfunction. Higher doses of lidocaine and diabetic status were independent predictors of cognitive decline. Protective effects of lower dose lidocaine in nondiabetic subjects need to be further evaluated.
authors.affiliation: Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA. mathe014@mc.duke.edu
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Mathew
authors.forename: G Burkhard
authors.initials: GB
authors.lastname: Mackensen
authors.forename: Barbara
authors.initials: B
authors.lastname: Phillips-Bute
authors.forename: Hilary P
authors.initials: HP
authors.lastname: Grocott
authors.forename: Donald D
authors.initials: DD
authors.lastname: Glower
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Laskowitz
authors.forename: James A
authors.initials: JA
authors.lastname: Blumenthal
authors.forename: Mark F
authors.initials: MF
authors.lastname: Newman
mesh_terms: D000368:Aged; D000758:Anesthesia; D000779:Anesthetics, Local / Q000627:therapeutic use*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003072:Cognition Disorders / Q000517:prevention & control* / Q000523:psychology; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007249:Inflammation / Q000517:prevention & control; D018836:Inflammation Mediators / Q000097:blood; D007361:Intelligence Tests; D008012:Lidocaine / Q000627:therapeutic use*; D008297:Male; D008568:Memory; D008875:Middle Aged; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D009483:Neuropsychological Tests; D011183:Postoperative Complications / Q000517:prevention & control* / Q000523:psychology; D011597:Psychomotor Performance / Q000502:physiology; D012044:Regression Analysis
chemical_list: D000779:Anesthetics, Local; D018836:Inflammation Mediators; D018696:Neuroprotective Agents; D008012:Lidocaine