title: Oxidative stress in coronary artery bypass surgery.
abstract: OBJECTIVE
  The aim of this prospective study was to assess the dynamics of oxidative stress during coronary artery bypass surgery with cardiopulmonary bypass.
  
  
  METHODS
  Sixteen patients undergoing coronary artery bypass grafting were enrolled. Blood samples were collected from the systemic circulation during anesthesia induction (radial artery--A1), the systemic venous return (B1 and B2) four minutes after removal of the aortic cross-clamping, of the coronary sinus (CS1 and CS2) four minutes after removal of the aortic cross-clamping and the systemic circulation four minutes after completion of cardiopulmonary bypass (radial artery--A2). The marker of oxidative stress, malondialdehyde, was measured using spectrophotometry.
  
  
  RESULTS
  The mean values of malondialdehyde were (ng/dl): A1 (265.1), B1 (490.0), CS1 (527.0), B2 (599.6), CS2 (685.0) and A2 (527.2). Comparisons between A1/B1, A1/CS1, A1/B2, A1/CS2, A1/A2 were significant, with ascending values (P<0.05). Comparisons between the measurements of the coronary sinus and venous reservoir after the two moments of reperfusion (B1/B2 and CS1/CS2) were higher when CS2 (P<0.05). Despite higher values after the end of cardiopulmonary bypass (A2), when compared to samples of anesthesia (A1), those show a downward trend when compared to the samples of the second moment of reperfusion (CS2) (P<0.05).
  
  
  CONCLUSIONS
  The measurement of malondialdehyde shows that coronary artery bypass grafting with cardiopulmonary bypass is accompanied by increase of free radicals and this trend gradually decreases after its completion. Aortic clamping exacerbates oxidative stress but has sharper decline after reperfusion when compared to systemic metabolism. The behavior of thiobarbituric acid species indicates that oxidative stress is an inevitable pathophysiological component.
authors.affiliation: Hélio Mandeta Medical School, Federal University of Mato Grosso do Sul, Campo Grande, MS, Brazil.
authors.forename: Amaury Edgardo Mont'Serrat Ávila Souza
authors.initials: AE
authors.lastname: Dias
authors.affiliation: Moscow State Universit, Moscow, Russia.
authors.forename: Petr
authors.initials: P
authors.lastname: Melnikov
authors.affiliation: Hélio Mandeta Medical School, Federal University of Mato Grosso do Sul, Campo Grande, MS, Brazil.
authors.forename: Lourdes Zélia Zanoni
authors.initials: LZ
authors.lastname: Cônsolo
mesh_terms: D015415:Biomarkers / Q000097:blood; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D054326:Coronary Sinus / Q000502:physiology; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation / Q000502:physiology*; D008297:Male; D008315:Malondialdehyde / Q000097:blood*; D018384:Oxidative Stress / Q000502:physiology*; D059035:Perioperative Period; D011446:Prospective Studies; D017534:Radial Artery / Q000737:chemistry; D013053:Spectrophotometry; D018709:Statistics, Nonparametric; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D013997:Time Factors
chemical_list: D015415:Biomarkers; D017392:Thiobarbituric Acid Reactive Substances; D008315:Malondialdehyde