503. Low Segment Spinal Surgery are Associated with Gram-Negative Surgical Site Infections (SSI)
Session: Poster Abstract Session: Surgical Site Infections
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
  • spine surgery.pdf (1.1 MB)
  • Background: SSIs occur following 5-8% of spinal fusion procedures. Typically, gram-positive organisms are found in early-onset SSIs within 30 days of the spinal procedure. However, modifiable risk factors and the correlation between specific types of organisms with different levels of spinal fusion procedures remain poorly understood. Thus, we sought to describe the current epidemiology of SSIs following spinal fusion procedures and to determine risk factors

    Methods: We performed a retrospective cohort study of all patients who underwent spinal fusion (identified by CPT codes), at Duke University Hospital from 1/1/2006 to 04/30/2012. SSIs were defined as those patients who required readmission and operative incision & drainage (I&D) procedure within 30 days of the primary spinal surgery. Descriptive statistics were used and logistic regression was performed to determine covariates that were associated with SSIs.

    Results: We analyzed 4918 unique cases of spinal fusions. The median age of patients was 57 years of age and 55% were female. The most common type of spinal fusions were anterior cervical fusion (1086, 22%), posterior lumbar fusion (988, 20%) and cervical posterior fusions (645, 13%). We found a total of 138 (2.8%) SSIs that required take back for I&D procedures; the procedures with the highest rate of SSIs were: posterior-approach osteotomy (7.2%) and anterior-posterior deformity correction (7%). The spinal fusion approaches with the lowest rates of SSIs were anterior cervical (0.28%) and anterior thoracic (0.8%) approaches.  Risk factors that were independently associated with SSIs included: diabetes, COPD, and using a posterior approach to surgery. Lower spinal fusion procedures (e.g. lumbar procedures) were significantly associated with SSIs due to gram-negative organisms (OR 1.92, 95%CI: 1.1-3.3).

    Conclusion: Posterior approach to spinal fusion, diabetes and COPD were independent predictors of SSIs following spine fusion. Optimizing glycemic control and respiratory function, and selecting anterior surgical approach where possible may reduce SSIs. Procedures on lower spinal segments (lumbar spine) are more often associated with gram-negative SSIs; therefore antibiotic prophylaxis for lower segment spinal surgery should have effective activity against enteric organisms.

    Luke F. Chen, MBBS, MPH, CIC, FRACP1, Matthew Roman1, Keith Michael, MD2, Thomas Hopkins, MD3, Deverick J. Anderson, MD, MPH4, William Richardson, MD2 and Daniel J. Sexton, MD, FIDSA1, (1)Duke University Medical Center, Durham, NC, (2)Department of Orthopaedics, Duke University Medical Center, Durham, NC, (3)Department of Anesthesia, Duke University Medical Center, Durham, NC, (4)Division of Infectious Diseases, Duke University Medical Center, Durham, NC


    L. F. Chen, Merck, Inc.: Grant Investigator, Research support
    Optimer Pharmaceuticals: Investigator and Speaker's Bureau, Research grant and Speaker honorarium
    Cubist Pharmaceuticals: Speaker's Bureau, Speaker honorarium

    M. Roman, None

    K. Michael, None

    T. Hopkins, None

    D. J. Anderson, None

    W. Richardson, None

    D. J. Sexton, None

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