Prospective Cohort Study in Evaluation of Risk Factors for Infection During and After Coronary Graft Operations.

Surgical site infections (SSIs) are either superficial or deep and may involve the organs, or spaces accessed during an operation. The reported incidence of SSIs in coronary artery bypass grafting (CABG) surgery ranges between 0.3% and 8%.

There is a strong suggestion that an impairment of vascular supply of the sternum may be one of the most important factors influencing the incidence of deep sternal wound infection (DSWI). Several studies have studied the risk factors for SSIs including DSWI in cardiac surgery. These risk factors included obesity, diabetes mellitus, chronic obstructive pulmonary disease (COPD), connective tissue disease, steroid use, smoking, peripheral vascular disease and renal insufficiency. In addition, intraoperative factors (e.g., use of bilateral internal mammary arteries [BIMA] grafting, prolonged cardiopulmonary bypass [CPB] duration) and postoperative variables (e.g., prolonged mechanical ventilation, reoperation for bleeding, postoperative transfusions and gastrointestinal, nephrological and respiratory complications) have been shown to be associated with DSWI.

The risk for sternal wound infection (SWI) is increased if cardiac surgery involves internal thoracic arteries grafting and a valve procedure, or use of a ventricular assist device.

Leg wound infections at donor sites account for >70% of cases with severe infection following cardiac surgery.

Cardiac SSIs increase the length of hospital stay (LOS) and increase treatment costs in proportion to the severity of the infection. These costs increase by 3.8%, 14.7% and 29.4% in mild, moderate and severe infections respectively.