title: S-100beta release in hypothermic circulatory arrest and coronary artery surgery.
abstract: BACKGROUND
  Aortic surgery utilizing profound hypothermic circulatory arrest (HCA) has a higher incidence of neurological injury than coronary artery bypass grafting (CABG). S-100beta is a potential marker of cerebral ischemic injury. The aim of this study is to assess its use in investigating cerebral injury during HCA.
  
  
  METHODS
  We studied 40 patients (10 CABG, 30 HCA). The mean cardiopulmonary bypass (CPB) times were 72 and 158 minutes, respectively. Mean HCA duration was 27.6 min, with retrograde cerebral perfusion (RCP) used in 18 patients (mean 28.5 minutes, 95% CI 16-25). Perioperative venous blood samples were subjected to S100beta assay.
  
  
  RESULTS
  S100beta levels with HCA (peak: 2.68 microg/L, 95% CI 1.99-3.38 microg/L; calculated area under the curve [AUC]: 1596 microg/L/min, 95% CI 825-2368 microg/L/min) were significantly higher (peak, p = 0.028 and AUC, p = 0.007) than with CABG (peak: 1.16 microg/L, 95% CI 0.25-2.1 microg/L and AUC: 53.4 microg/L/min 95% CI 3.0-103.8). Peak S100beta correlated with CPB time in CABG cases (r = 0.76, p < 0.05), and with both CPB and HCA time in HCA cases: without RCP (r = 0.46 and 0.21, respectively, p > 0.05) and with RCP (r = 0.88 and 0.33, respectively, p < 0.05). There was no significant difference in the S100beta levels between HCA groups with and without RCP, but HCA time was longer in the RCP group (p = 0.05).
  
  
  CONCLUSIONS
  S100beta release correlates with duration of CPB and HCA. Elevated serum S100 indicates astrocyte death or activation, and suggests blood-brain barrier dysfunction. The continuing release of S100 after the end of operation suggests that HCA may be associated with greater injury than CABG. RCP did not influence S-100beta release in this study.
authors.affiliation: Cardiothoracic Surgical Unit, University Hospital Birmingham, Queen Elizabeth Medical Centre, Edgbaston, United Kingdom.
authors.forename: C H
authors.initials: CH
authors.lastname: Wong
authors.forename: S J
authors.initials: SJ
authors.lastname: Rooney
authors.forename: R S
authors.initials: RS
authors.lastname: Bonser
mesh_terms: D001011:Aorta / Q000601:surgery*; D015415:Biomarkers; D002545:Brain Ischemia / Q000097:blood*; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D005112:Extracorporeal Circulation; D006324:Heart Arrest, Induced; D006331:Heart Diseases / Q000601:surgery; D006801:Humans; D007036:Hypothermia, Induced; D008875:Middle Aged; D010477:Perfusion / Q000379:methods; D011183:Postoperative Complications / Q000097:blood*; D009418:S100 Proteins / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D009418:S100 Proteins