title: Cerebral monitors versus regional anesthesia to detect cerebral ischemia in patients undergoing carotid endarterectomy: a meta-analysis.
abstract: OBJECTIVE
  The aim of this meta-analysis is to compare the ability of different types of brain monitoring systems vs clinical monitoring of the brain function to detect cerebral ischemia during cross-clamping of the carotid artery under regional anesthesia.
  
  
  METHODS
  In May 2012, a search was conducted in PubMed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Ovid MEDLINE for prospective trials with 20 patients or more where a cerebral monitoring system was compared with clinical brain monitoring during a carotid endarterectomy performed under regional anesthesia. The quality of the study was evaluated with the Cochrane Collaboration's tool. Data were extracted independently by the two investigators.
  
  
  RESULTS
  Data could be extracted for 4,664 measurements taken from 29 studies: transcranial Doppler (TCD) = 739; cerebral saturation = 320; stump pressure = 2,549; electroencephalography (EEG) = 742; evoked potentials = 187; jugular venous saturation = 79; and jugular venous lactate = 48. The pooled diagnostic odds ratios (DOR) and 95% confidence intervals (CI) were obtained for EEG, TCD, stump pressure, evoked potentials, and cerebral saturation: (DOR 65.3; 95% CI 20.5 to 207.7; I(2) [56.8%]); (DOR 58.1; 95% CI 23.0 to 146.3; I(2) [24.9%]); (DOR 27.8; 95% CI 13.4 to 57.9; I(2) [59.9]); (DOR 17.2; 95% CI 2.4 to 123.9 I(2) [69.1]); and (DOR 12.1; 95% CI 3.5 to 41.2; I(2) [30.8]), respectively. Sequential testing with stump pressure 25 mmHg followed by either TCD or EEG delivered the best post-test probabilities. For EEG, the DOR increases with the number of channels used (P = 0.03).
  
  
  CONCLUSIONS
  A combination of stump pressure and either TCD or EEG appears to deliver the best results for detecting brain ischemia during carotid artery cross-clamping. Electroencephalography should be used with a high number of channels.
authors: Department of Anesthesiology, University of Montreal, Montreal, QC, Canada. joanneguay@bell.net
authors: Joanne
authors: J
authors: Guay
authors: Sandra
authors: S
authors: Kopp
mesh_terms: D000765:Anesthesia, Conduction / Q000009:adverse effects / Q000379:methods; D002545:Brain Ischemia / Q000175:diagnosis* / Q000209:etiology; D004569:Electroencephalography / Q000379:methods; D016894:Endarterectomy, Carotid / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D016343:Monitoring, Intraoperative / Q000379:methods*; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods