title: Ventilation during cardiopulmonary bypass: impact on heat shock protein release.
abstract: OBJECTIVE
  Cardiopulmonary bypass (CPB), utilized in on-pump coronary artery bypass graft procedures (CABG) induces generalized immune suppression, release of heat shock proteins (HSP), inflammatory markers and apoptosis-specific proteins. We hypothesized that continued mechanical ventilation during cardiopulmonary bypass attenuates immune response and HSP liberation.
  
  
  METHODS
  Thirty patients undergoing conventional coronary artery bypass graft (CABG) operation were randomized into a ventilated on CPB (VG; N.=15) and a non-ventilated CPB group (NVG; N.=15). Blood samples were drawn at the beginning and end of surgery, as well as on the five consecutive postoperative days (POD). Molecular markers were measured by ELISA. Data are given as mean ± (SD). Mann-Whitney-U-test was used for statistical analysis.
  
  
  RESULTS
  Serum concentrations of HSP70 were significantly lower in VG compared to NVG on POD-1 (VG: 1629±608 vs. NVG: 5203±2128.6 pg/mL, P<0.001). HSP27 and HSP60 depicted a minor increase in both study groups at the end of surgery without any intergroup differences (HSP27: VG 6207.9±1252.5 vs. NVG 7424.1±2632.5; HSP60: VG 1046.2±478.8 vs. NVG 1223.5±510.1). IL-8 and CK-18 M30 evidenced the highest serum concentrations at the end of surgery (IL-8: VG 119.5±77.9 vs. NVG 148.0±184.55; CK-18 M30: VG 62.1±39.2 vs. NVG 67.5±33.9) with no differences between groups. Decreased ICAM-1 serum concentrations were detected postoperatively, however ICAM-1 concentrations on POD-1 to POD-5 showed slightly elevated concentrations in both study groups with no intergroup differences.
  
  
  CONCLUSIONS
  Significantly less HSP70 was detectable in patients receiving uninterrupted mechanical lung ventilation on CPB, indicating either different inflammatory response, cellular stress or cell damage between the ventilated and non-ventilated group. These data suggest that continued mechanical ventilation has a modulatory effect on the immune response in patients after CABG surgery.
authors.affiliation: Department of Thoracic Surgery Medical University Vienna, Vienna, Austria - hendrik.ankersmit@meduniwien.ac.at.
authors.forename: L
authors.initials: L
authors.lastname: Beer
authors.forename: T
authors.initials: T
authors.lastname: Szerafin
authors.forename: A
authors.initials: A
authors.lastname: Mitterbauer
authors.forename: M M
authors.initials: MM
authors.lastname: Kasiri
authors.forename: L
authors.initials: L
authors.lastname: Debreceni T Palotás
authors.forename: M
authors.initials: M
authors.lastname: Dworschak
authors.forename: G A
authors.initials: GA
authors.lastname: Roth
authors.forename: H J
authors.initials: HJ
authors.lastname: Ankersmit
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001317:Austria; D015415:Biomarkers / Q000097:blood; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D018834:Chaperonin 60 / Q000097:blood; D001026:Coronary Artery Bypass / Q000379:methods*; D005260:Female; D055551:HSP27 Heat-Shock Proteins / Q000097:blood; D018840:HSP70 Heat-Shock Proteins / Q000097:blood; D006360:Heat-Shock Proteins / Q000097:blood*; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000209:etiology / Q000276:immunology / Q000517:prevention & control*; D018836:Inflammation Mediators / Q000097:blood; D008297:Male; D008875:Middle Aged; D024101:Mitochondrial Proteins / Q000097:blood; D018832:Molecular Chaperones; D012121:Respiration, Artificial; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D018834:Chaperonin 60; D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; C057725:HSPB1 protein, human; C060293:HSPD1 protein, human; D006360:Heat-Shock Proteins; D018836:Inflammation Mediators; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones