title: The effects of cardiopulmonary bypass on the number of cerebral microemboli and the incidence of cognitive dysfunction after coronary artery bypass graft surgery.
abstract: BACKGROUND
  Postoperative cognitive dysfunction (POCD) can be a debilitating complication after coronary artery bypass graft (CABG) surgery. Cerebral microemboli during cardiopulmonary bypass (CPB) are believed to be an important etiologic factor of POCD. In this study, we examined whether avoidance of CPB with "off-pump" surgery reduces the number of cerebral microemboli and the incidence of POCD after CABG surgery in Chinese population.
  
  
  METHODS
  Two hundred twenty-seven patients were enrolled in this prospective cohort study. Fifty-nine patients underwent CABG surgery with CPB and 168 underwent off-pump surgery. Cerebral microemboli were measured continuously with bilateral transcranial Doppler ultrasonography of the middle cerebral arteries. A neuropsychological test battery that included seven tests with nine subscales was administered at baseline, as well as at 1 wk and 3 mo after surgery. POCD was defined using the international study of POCD1 definition.
  
  
  RESULTS
  The median total number of cerebral microemboli for the case was 430 (range: 155-2088) in patients undergoing surgery with CPB and 2 (0-66) in the off-pump patients (P < 0.001). There were no differences in the incidence of POCD between the patients having surgery with or without CPB either at 1 wk (55.2% or 32 of 58 patients [95% confidence interval: 41.5%-68.3%] vs 47.0% or 78 of 166 patients [39.2%-54.9%], P = 0.283) or 3 mo (6.4% or 3 of 47 patients [1.3%-17.5%] vs 13.1% or 16 of 122 of patients [7.7%-20.4%], P = 0.214) after surgery. Increasing age and shorter duration of postoperative hospital stay were independently associated with cognitive dysfunction at 1 wk after surgery. Increasing age and a history of diabetes mellitus were independently associated with cognitive dysfunction 3 mo after surgery. CPB or cerebral microemboli were not significantly related to the occurrence of POCD.
  
  
  CONCLUSIONS
  In Chinese population, avoidance of CPB during CABG surgery significantly decreased the number of cerebral microemboli, but it did not decrease the incidence of POCD at either 1 wk or 3 mo after CABG. Neither CPB nor cerebral microemboli was independently associated with the risk of POCD.
authors.affiliation: Department of Anesthesiology, Peking University First Hospital, Beijing 100034, China.
authors.forename: Ying-Hua
authors.initials: YH
authors.lastname: Liu
authors.forename: Dong-Xin
authors.initials: DX
authors.lastname: Wang
authors.forename: Li-Huan
authors.initials: LH
authors.lastname: Li
authors.forename: Xin-Min
authors.initials: XM
authors.lastname: Wu
authors.forename: Guo-Jin
authors.initials: GJ
authors.lastname: Shan
authors.forename: Yu
authors.initials: Y
authors.lastname: Su
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Qin-Jun
authors.initials: QJ
authors.lastname: Yu
authors.forename: Chun-Xia
authors.initials: CX
authors.lastname: Shi
authors.forename: Yi-Ning
authors.initials: YN
authors.lastname: Huang
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
mesh_terms: D000367:Age Factors; D000368:Aged; D044466:Asian People; D002315:Cardiopulmonary Bypass / Q000009:adverse effects* / Q000401:mortality; D002681:China; D003072:Cognition Disorders / Q000175:diagnosis / Q000208:ethnology / Q000209:etiology* / Q000517:prevention & control; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000401:mortality; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects* / Q000401:mortality; D048909:Diabetes Complications / Q000209:etiology; D005260:Female; D006801:Humans; D015994:Incidence; D020766:Intracranial Embolism / Q000000981:diagnostic imaging / Q000208:ethnology / Q000209:etiology* / Q000517:prevention & control; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000209:etiology; D013997:Time Factors; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial