516. Difference in the Risk Factors for Surgical Site Infections Following Two Types of Cardiac Surgery in Japanese Patients
Session: Poster Abstract Session: Surgical Site Infections
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
  • 131003IDSAPoster.pdf (468.7 kB)
  • Background:  Surgical site infection (SSI) is one of the most serious postoperative complications. Identifying risk factors associated with SSI and focusing prevention efforts on patients with those factors are essential. Traditionally, SSI rates are risk stratified using the National Nosocomial Infections Surveillance (NNIS) risk index, which consists of three variables: the American Society of Anesthesiologist’s (ASA) score, wound class, duration of operation. In cardiac surgery, where most of the operations are clean and are performed on patients with higher ASA score, this scheme of stratification has been criticized against its poor prediction of SSI.  Also, these discussions have been made without clearly demarcating two type of cardiac surgery, coronary bypass graft and open heart operations.

    Methods:  SSI surveillance data on coronary bypass graft operations (CBGB) and open heart operations (CARD) submitted to the Japan Nosocomial Infection Surveillance (JANIS) system in 2008-2010 were analyzed. Besides the variables in the NNIS risk index, age, emergent surgery, general anesthesia, implant, multiple procedures, sex and trauma were used to assess the risk of SSI. Continuous variables such as duration and age were initially analyzed for their appropriateness of categorization. Factors that were significant in bivariate analysis were entered into a stepwise logistic regression model, which was used to assess independent importance of potential risk factors.

    Results:  The cumulative incidence of SSI for operations on CARD and CBGB were 2.56%(151/5,895) and 4.12%(160/3,884). In both of the groups, duration and ASA score were significant in predicting SSI risk in the model. Wound class was also significant in CARD, but not in CBGB, possibly because 99% of procedures in CBGB were clean. Implant, multiple procedures and emergent operation predicted SSI in CARD, but none of them predicted SSI in CBGB.

    Conclusion:  There was a remarkable difference in prediction of SSI between two cardiac operations. Risk index stratification in CBGB should be enhanced by collecting additional variables, because there are only two factors that were significant in predicting SSI among currently collected variables.

    Keita Morikane, MD, PhD, Infection Control, Yamagata University Hospital, Yamagata, Japan, Hitoshi Honda, MD, Division of Infectious Diseases and Department of Infection Prevention, Tokyo Metropolitan Tama Medical Center, Fuchu, Tokyo, Japan, Takuya Yamagishi, MD, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan and Satowa Suzuki, MD, PhD, National Institute of Infectious Diseases, Tokyo, Japan


    K. Morikane, None

    H. Honda, None

    T. Yamagishi, None

    S. Suzuki, None

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