Hygienic interventions to decrease deep sternal wound infections following coronary artery bypass grafting

Abstract

The department of Cardiothoracic Surgery at Uppsala University Hospital has 25 beds in one to four patient rooms and an operating suite consisting of five operating rooms with ultraclean air. Around 700 open heart (250 isolated coronary artery bypass grafting, CABG) operations are performed annually. In 2009, the numbers of deep sternal wound infections (DSWIs) increased to unacceptable rates despite existing hygienic guidelines. To show how root cause analysis (RCA) followed by quality improvement interventions reduced the rate of DSWI after CABG surgery. Only isolated CABG patients requiring surgical revision due to DSWI were included. Swabs and tissue biopsies were taken during surgical revision and analysed with standard methods. DSWIs were registered prospectively according to US Centers for Disease Control and Prevention definitions. RCA for infection was performed between September 2009 and April 2010. Interventions based on results of the RCA and on nationally recommended practices were concluded in April 2010, and thought to have taken full effect by July 1st, 2010. Air was actively sampled at ≤0.5m from the sternal incision. DSWI incidence rates per CABG operations decreased from 5.1% pre intervention to 0.9% post intervention. Wound cultures pre intervention grew Staphylococcus aureus 27.1% and coagulase negative staphylococcus (CoNS) 47.1%, post intervention S.aureus 23.1% and CoNS 30.8%. Air counts did not exceed 5cfu/m(3). When the aetiology of an error is multifactorial, RCA engaging both the medical professions and the infection control team is a potential tool to map causes leading to adverse events such as healthcare-associated infections. A systematic quality improvement intervention based on the RCA may reduce the number of deep sternal wound infections after CABG surgery.