Risk Factors for 30-Day Hospital Re-Admission with an Infectious Complication after Lower-Extremity Vascular Procedures

Background: Lowering the 30-d re-admission rate after vascular surgery offers the potential to improve healthcare quality. This study evaluated re-admission associated with infections after open and endovascular lower extremity (LE) procedures for peripheral artery disease (PAD). Methods: Patients admitted for elective LE procedures for PAD were selected from the Cerner Health Facts((R)) database. Chi-square analysis evaluated the characteristics of the index admission associated with infection at 30-d re-admission. Multivariable logistic models were created to examine the association of patient and procedural characteristics with infections at re-admission. The microbiology data available at the time of re-admission were evaluated also. Results: A total of 7,089 patients underwent elective LE procedures, of whom 770 (10.9%) were re-admitted within 30d. A total of 289 (37.5%) had a diagnosis of infection during the re-admission. These infections included surgical site (14.8%), cellulitis (13.6%), sepsis (8.8%), urinary tract (4.9%), and pneumonia (4.9%). Index stay factors associated with infection at re-admission were fluid and electrolyte disorders, kidney disease, diabetes, previous infection, and chronic anemia. Laboratory results associated with an infection during re-admission were post-operative hemoglobin <8g/dL, blood urea nitrogen >20mg/dL, platelet counts >400x10(3)/mcL, glucose >180mg/dL, and white blood cell count >11.0x10(3)/mcL. Adjusted models demonstrated longer stay, chronic anemia, previous infection, treatment at a teaching hospital, and hemoglobin <8g/dL to be risk factors for re-admission with infection. Infective organisms isolated during the re-admission stay included Staphylococcus, Enterococcus, Escherichia, Pseudomonas, Proteus, and Klebsiella. Conclusions: Infectious complications were associated with more than one-third of all re-admissions after LE procedures. Predictors of re-admission within 30d with an infectious complication were longer stay, greater co-morbidity burden, hospitalization in teaching facilities, hemoglobin <8g/dL, and an infection during the index stay. Microbiology examination at re-admission demonstrated gram-negative bacteria in more than 40% of infections. Further evaluation of high-risk vascular patients prior to discharge and consideration of antibiotic administration for gram-negative organisms at the time of re-admission may improve outcomes.