The Investigation of the Causes of Hepatic Dysfunction in the Postoperative Period During Open-heart Surgeries
Condition: Hyperbilirubinemia; Hepatic Impairment; Surgery; Cardiac Disease
MeSH terms: Heart Diseases; Hyperbilirubinemia
Study type: Observational [Patient Registry]

Summary: 
      In a prospective observational study during the six-month duration, coronary artery bypass
      graft surgery (CABG) and valve repair surgery (mitral, mitral, and aortic valve and/or
      tricuspid valve) patients were investigated for hepatic dysfunction. All patients were
      divided into two groups as with or without hyperbilirubinemia, and this was defined by the
      occurrence of a plasma total bilirubin concentration of more than 34 µmol/L (2 mg/dL) in any
      measurement during the postoperative period. Our goal was to determine the risk factors
      associated with hepatic dysfunction in patients undergoing open-heart surgery with
      cardiopulmonary bypass. The collected parameters include; alanine transaminase (ALT),
      aspartate transaminase (AST), alkaline phosphatase (ALP), total bilirubin (TBIL), and
      gamma-glutamyl transpeptidase (GGT) and albumin preoperatively and on postoperative days 1, 3
      and 7. Possible preoperative, intraoperative, and postoperative risk factors were
      investigated. Logistic regression analysis was done to identify the risk factors for
      postoperative hyperbilirubinemia.
    

Detailed description: 
      There are a series of pathophysiological changes in patients undergoing open-heart surgeries
      with cardiopulmonary bypass (CPB) that causes liver hypoperfusion, centrilobular sinusoid
      ischemia, and subsequent reperfusion injuries, hemolysis, or systemic inflammatory response.
      These events may eventually lead to various forms of hepatic dysfunction in patients during
      the postoperative period after open-heart surgeries. An increased incidence of liver function
      test abnormalities were reported, and the rates vary between 10 % and 40%. The occurrence of
      postoperative hyperbilirubinemia is crucial in increased morbidity and mortality after
      open-heart surgery with CPB. There are several reports of the possible risk factors that are
      associated with hepatic dysfunction. In previous studies, the incidence of postoperative
      hyperbilirubinemia was between the range of 20% up to 51% in open-heart surgeries with CPB.
      The causes of this higher incidence were related to the presence of various possible risk
      factors, and these include; valvular heart disease and related low cardiac output states, and
      low ejection fraction. Other important risk factors for postoperative hepatic dysfunction
      after open-heart surgery with CPB were longer operative time and a larger volume of blood
      transfusion. However, CPB itself is not a significant constituent in the postoperative
      development of hyperbilirubinemia. Splanchnic ischemia before or during operation and in the
      postoperative period appears to be an essential cause. Other risk factors that were
      identified as possible risk factors for postoperative hepatic dysfunction. We can list these
      factors as; poor preoperative heart function, hemodynamic instability, emergency surgery, and
      preoperative liver dysfunction. Our goal was to determine the possible risk factors
      associated with hepatic dysfunction in patients undergoing open-heart surgery with CPB.
    

Intervention name(s): Open-Heart Surgery for nine months duration; Relation between possible risk factors and hyperbilirubinemia; Follow-up period
Intervention type(s): Procedure; Other; Other
Intervention description(s): In a single group of patients including 340 patients undergoing open-heart surgery during a period of nine months, the collected parameters include; alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total bilirubin (TBIL), and gamma-glutamyl transpeptidase (GGT) and albumin preoperatively and on postoperative days of 1, 3 and 7. All patients were divided into two groups as with or without hyperbilirubinemia, and this was defined by the occurrence of a plasma total bilirubin concentration of more than 34 µmol/L (2 mg/dL) in any measurement during the postoperative period. For each diagnostic test, a comparison within the group for different time points was statistically evaluated by analysis of variance tests.; Possible preoperative, intraoperative, and postoperative risk factors were investigated. The relations between hyperbilirubinemia and possible risk factors are sought by the use of the statistical analysis methods including logistic regression analysis.; All patients were investigated for a period of ten days postoperatively. During this period, intensive care unit (ICU) stay, in-hospital stay, and all adverse events were recorded.
Other intervention name(s): Type of open-heart surgical operation (coronary artery bypass graft operation, mitral valve, aortic valve or multiple valvular surgeries); Hyperbilirubinemia; Hepatic function related tests
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        The study is performed on a patient population undergoing open-heart surgery with
        cardiopulmonary bypass.
      
Keywords: open-heart surgery; postoperative; complications; hyperbilirubinemia; hepatic impairment