Risk Factors of Sternal Wound Infection After Coronary Artery Bypass Graft

• postoperative surgical wound infection [ Time Frame: within first week after the end of coronary artery bypass graft surgery ] [ Designated as safety issue: No ]
  postoperative surgical wound infection within first week after the end of coronary artery bypass graft surgery, classified as a superfical or deep sternal wound infection
  
  

• preoperative total leukocyte count [ Time Frame: 1 day before surgery ] [ Designated as safety issue: No ]
  preoperative total leukocyte count
  
  
• preoperative neutrophil count [ Time Frame: 1 day before surgery ] [ Designated as safety issue: No ]
  preoperative neutrophil count
  
  
• preoperative lymphocyte count [ Time Frame: 1 day before surgery ] [ Designated as safety issue: No ]
  preoperative lymphocyte count
  
  
• postoperative total leukocyte count [ Time Frame: 2 hour after the end of surgery ] [ Designated as safety issue: No ]
  postoprative total leukocyte count
  
  
• postoperative neutrophil count [ Time Frame: 2 hour after the end of surgery ] [ Designated as safety issue: No ]
  postoperative neutrophil count
  
  
• postoperative lymphocyte count [ Time Frame: 2 hour after the end of surgery ] [ Designated as safety issue: No ]
  postoperative lymphocyte count
  
  
• preoperative NNIS risk index [ Time Frame: 1 day before surgery ] [ Designated as safety issue: No ]
  preoperative NNIS risk index
  
  
• preoperative EuroScore [ Time Frame: 1 day before surgery ] [ Designated as safety issue: No ]
  preoperative EuroScore
  
  
• Preoperative STS [ Time Frame: 1 day before surgery ] [ Designated as safety issue: No ]
  Preoperative STS (Society of Thoracic Surgeons risk score)
  
  
• the incidence of surgical reopen with surgical wound infection [ Time Frame: within 1 month after surgery ] [ Designated as safety issue: No ]
  the incidence of surgical reopen with surgical wound infection
  
  

Deep sternal wound infection after coronary artery bypass graft is a very dangerous complication as it prolongs hospital stay, increase morbidity and mortality, and increase cost of care.

As a risk factor of surgical site infection, risk index reported by NNIS (national nosocomial infection surveillance), Euroscore, or Society of thoracic surgeon risk score are currently used. However, as various performances are reported regarding these index or scoring systems, and many factors are needed for these index or scoring system, there is a need to develop a more simple risk factor with better performance. We focused on the differential blood cell count, as the neutrophil and lymphocyte count are related to the degree of surgical invasion, and inflammatory response. Previous studies reported that the neutrophilia or lymphopenia is related to postoperative infection. Therefore, we are trying to evaluate the performance of preoperative or postoperative the blood cell differential count as a risk factor for sternal wound infection after coronary artery bypass surgery.