122 - Incidence and Mortality of Surgical Site Infections after Lumbar Spine...

#122 Incidence and Mortality of Surgical Site Infections after Lumbar Spine Surgery

General Session: Infections/Tumor

Presented by: K. Singh

Author(s):

M. Pelton (1)
S.J. Fineberg (1)
M. Oglesby (1)
K. Singh (1)
A. Patel (2)

(1) Rush University Medical Center, Orthopaedic Surgery, Chicago, IL, USA
(2) Northwestern University Feinberg School of Medicine, Orthopaedic

Abstract

Introduction: Surgical site infections (SSI) are one of the most common complications after orthopaedic procedures. The incidence of SSI in lumbar spine surgery has not been reported in large patient populations. In order to characterize the national burden of SSI, a population-based database was analyzed to identify incidence, mortality, and costs associated with lumbar decompressions (LD) and lumbar fusions (LF).

Methods: Data from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project was obtained for each year from 2002-2009. Patients undergoing LD (i.e. laminectomy +/- discectomy), or LF for the diagnosis of lumbar radiculopathy, herniated nucleus pulposus, degenerative disc disorder, and spinal stenosis were included. Incidences of SSI were identified and calculated. Co-morbidities were calculated using a modified Charlson Co-morbidity Index (CCI). Mortality associated with SSI was also assessed. Statistical analysis was performed using Student T-test for discrete variables, and χ2-test for categorical data. Logistic regression was used to identify independent predictors of SSI. A p-value of < 0.0005 was used to denote significance.

Results: A total 578,457 lumbar procedures were identified from 2002-2009 in the United (Table 1). Incidences (per 1,000 cases) of SSI were 7.4 and 8.4 for the LD and LF groups respectively. Patients with SSI demonstrated increased co-morbidity scores, hospitalizations, and costs (p< 0.0005). SSI´s were associated with increased incidences of in-hospital mortality of 18.9 and 16.4 for the LD and LF groups respectively (p<0.0005). Comparison of SSI patients across the surgical groups demonstrated an increased rate of SSI, increased hospitalizations and costs in the LF group (p< 0.0005). Logistic regression identified the most significant predictors of SSI are anemia, drug abuse, liver disease, fluid/electrolyte disorders, and weight loss.

Discussion/Conclusion: Our study demonstrates a national incidence of 0.8% for SSI in patients undergoing lumbar spine surgery. SSI´s in both surgical groups resulted in increased hospitalization, costs, and mortality. The incidence of infection is significantly higher after LF compared with LD. We conclude that patients undergoing lumbar surgery with particular co-morbidities (anemia, drug abuse, liver disease, fluid/electrolyte disorders and weight loss) are at an increased risk for SSI. Peri-operative antibiotic protocols and pre-operative risk factors should be identified to decrease incidence of SSI in patients at greatest risk of infection.

Table 1