title: Incidence of postoperative cognitive dysfunction after general or spinal anaesthesia for extracorporeal shock wave lithotripsy.
abstract: BACKGROUND
  Since general anaesthesia invariably accompanies surgery, the contribution of each to the development of postoperative cognitive dysfunction (POCD) has been difficult to identify.
  
  
  METHODS
  A prospective randomized controlled trial was undertaken in elderly patients undergoing extracorporeal shock wave lithotripsy (ESWL). Between 2005 and 2011, 2706 individuals were screened to recruit 100 eligible patients. Patients were randomly assigned to receive general or spinal anaesthesia alone. A battery of eight neuropsychological tests was administered before operation and at 7 days and 3 months after operation. The reliable change index was used to calculate the incidence of POCD. Intention-to-treat analysis was used to compare rates of POCD.
  
  
  RESULTS
  Futility analysis led to stopping of the trial after recruitment of 100 patients. Fifty patients were randomly assigned to general anaesthesia, and 48 patients to spinal anaesthesia without sedation or postoperative opioids. At 3 months, POCD was detected in 6.8% [95% confidence interval (CI): 1.4-18.7%] of patients in the general anaesthesia group and 19.6% (95% CI: 9.4-33.9%) in the spinal group (P=0.07). At 7 days after operation, the incidence of POCD was 4.1% (95% CI: 0.5-14%) in the general anaesthesia group and 11.9% (95% CI: 4.0-26.6%) in the spinal group (P=0.16).
  
  
  CONCLUSIONS
  We found no significant difference in the rates of POCD when comparing general anaesthesia with spinal anaesthesia, suggesting that the surgical or procedural process itself may contribute to the development of POCD.
  
  
  BACKGROUND
  Australian Clinical Trials Registry number ACTRN12605000150640.
authors: Centre for Anaesthesia and Cognitive Function, Department of Anaesthesia, St Vincent's Hospital, Melbourne, PO Box 2900, Fitzroy, VIC 3065, Australia Anaesthesia, Perioperative and Pain Medicine Unit, Melbourne Medical School, University of Melbourne, Australia brendan.silbert@svhm.org.au.
authors: B S
authors: BS
authors: Silbert
authors: Centre for Anaesthesia and Cognitive Function, Department of Anaesthesia, St Vincent's Hospital, Melbourne, PO Box 2900, Fitzroy, VIC 3065, Australia Anaesthesia, Perioperative and Pain Medicine Unit, Melbourne Medical School, University of Melbourne, Australia.
authors: L A
authors: LA
authors: Evered
authors: Centre for Anaesthesia and Cognitive Function, Department of Anaesthesia, St Vincent's Hospital, Melbourne, PO Box 2900, Fitzroy, VIC 3065, Australia Anaesthesia, Perioperative and Pain Medicine Unit, Melbourne Medical School, University of Melbourne, Australia.
authors: D A
authors: DA
authors: Scott
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000768:Anesthesia, General / Q000009:adverse effects*; D000775:Anesthesia, Spinal / Q000009:adverse effects*; D003072:Cognition Disorders / Q000453:epidemiology* / Q000209:etiology* / Q000523:psychology; D005260:Female; D006801:Humans; D015994:Incidence; D008096:Lithotripsy / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011183:Postoperative Complications / Q000453:epidemiology* / Q000523:psychology*; D011446:Prospective Studies
keywords: cognition; general anaesthesia; postoperative cognitive dysfunction; spinal anaesthesia