M. L. Barnes1, J. T. Wiseman1, S. Saha1, J. Havlena1, S. Fernandes-Taylor1, K. C. Kent1 1University Of Wisconsin School Of Medicine And Public Health,Wisconsin Surgical Outcomes Research Program,Madison, WI, USA
Introduction: Surgical site infection (SSI) after vascular surgery is one of the most common post-operative complications and is the leading cause of unplanned, potentially preventable hospital readmissions among surgical patients. Transitional care interventions to detect SSI after hospital discharge may help stem the burden of readmissions and morbidity associated with SSI; however little is known regarding the classification of patients at high-risk for development of SSI occurring after hospital discharge (postSSI).
Methods: Patients who underwent major vascular surgery (abdominal aortic aneurysm, open aortoiliac, and lower extremity revascularization procedures) from 2005-2012 were identified from the American College of Surgeons National Surgical Quality Improvement Program Participant Use Files. Patients were categorized as having no SSI, SSI while in-hospital (preSSI), or postSSI. Multivariable logistic regression was performed using patient demographics, preoperative health characteristics and comorbidities, and operative variables to predict preSSI and postSSI.
Results: Of the 50,091 patients who underwent major vascular surgery, 4,481 (9.0%) were diagnosed with SSI (2.1% preSSI; 6.8% postSSI). Multivariate predictors of both preSSI and postSSI include obesity vs. normal BMI (preSSI odds ratio [OR]:1.6; 95% confidence interval [CI]: 1.3-2.0) (postSSI OR: 2.2; 95% CI: 2.0-2.5) an existing open wound or wound infection (preSSI OR:1.2; 95% CI: 1.0-1.5) (postSSI OR:1.2; 95% CI: 1.1-1.3). Multivariate predictors unique to patients who experienced preSSI include totally dependent functional status (OR: 2.7; 95% CI: 1.8-4.0), emergency case (OR: 2.5, 95% CI: 1.9-3.1), chronic obstructive pulmonary disease (OR:1.4; 95% CI: 1.1-1.8) and prolonged operative time (OR:1.3; 95% CI: 1.0-1.7). Multivariate predictors unique to patients who experienced postSSI include female gender (OR:1.4; 95% CI 1.3-1.5), overweight vs. normal BMI (OR:1.3; 95% CI: 1.2-1.5), insulin dependent and non-dependent diabetes mellitus (OR:1.4; 95% CI: 1.2-1.5) (OR:1.3; 95% CI: 1.1-1.4), dyspnea with moderate exertion (OR:1.1; 95% CI: 1.0-1.3), rest pain/gangrene (OR:1.4; 95% CI: 1.3-1.5), coronary artery disease (OR:1.1; 95% CI: 1.0-1.2), hypertension requiring treatment (OR: 1.2; 95% CI: 1.1-1.4), peripheral vascular disease (OR:1.3; 95% CI: 1.2-1.4), smoking (OR:1.2; 95% CI: 1.1-1.3) and neurological disease (OR:1.1; 95% CI: 1.0-1.3).
Conclusions: Predictors of preSSI after major vascular surgery are largely acute non-modifiable conditions whereas predictors of postSSI are primarily chronic comorbidities. Appropriate identification of these different sets of risk factors may improve both in-hospital wound surveillance and subsequent transitional care efforts to improve wound monitoring