Thomsen, Kristine M.

Background Surgical site infections (SSIs) result in significant patient morbidity following immediate tissue expander breast reconstruction (ITEBR). This study determined a single institution's 30-day SSI rate and benchmarked it against that among national institutions participating in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). Methods Women who underwent ITEBR with/without acellular dermal matrix (ADM) were identified using the ACS-NSQIP database between 2005 and 2011. Patient characteristics associated with the 30-day SSI rate were determined, and differences in rates between our institution and the national database were assessed. Results 12,163 patients underwent ITEBR, including 263 at our institution. SSIs occurred in 416 (3.4%) patients nationwide excluding our institution, with lower rates observed at our institution (1.9%). Nationwide, SSIs were significantly more common in ITEBR patients with ADM (4.5%) compared to non-ADM patients (3.2%, P=0.005), and this trend was observed at our institution (2.1% vs. 1.6%, P=1.00). A multivariable analysis of all institutions identified age ≥50 years (odds ratio [OR], 1.4; confidence interval [CI], 1.1-1.7), body mass index ≥30 kg/m2 vs. <25 kg/m2 (OR, 3.4; CI, 2.6-4.5), and operative time >4.25 hours (OR, 1.9; CI, 1.5-2.4) as risk factors for SSIs. Our institutional SSI rate was lower than the nationwide rate (OR, 0.4; CI, 0.2-1.1), although this difference was not statistically significant (P=0.07). Conclusions The 30-day SSI rate at our institution in patients who underwent ITEBR was lower than the nation. SSIs occurred more frequently in procedures involving ADM both nationally and at our institution.

ABSTRACT The role of combination antibiotic therapy with a beta-lactam and a fluoroquinolone for bacteremia caused by gram-negative bacilli, to our knowledge, has not been previously described. Much of the previous study of combination therapy has included beta-lactams and aminoglycosides. We conducted a large retrospective cohort study to evaluate 28-day all-cause mortality in patients with monomicrobial bacteremia due to aerobic gram-negative bacilli who received either a combination of beta-lactams and fluoroquinolones or beta-lactam monotherapy. We enrolled adult patients admitted to Mayo Clinic hospitals from 1 January 2001 to 31 October 2006 in the study. After stratification of patients by Pitt bacteremia scores, we used Cox regression models to estimate the hazard ratios (HR) for 28-day all-cause mortality after adjusting for the propensity to receive combination therapy. We identified 398 and 304 unique patients with bacteremia caused by gram-negative bacilli who received single and combination antibiotic therapy, respectively. In less severely ill patients with Pitt bacteremia scores of <4, combination therapy was associated with lower 28-day mortality than single therapy (4.2% [9 of 214] versus 8.8% [28 of 319]; adjusted HR, 0.44; 95% confidence interval [CI], 0.20 to 0.98; P = 0.044). In critically ill patients with Pitt bacteremia scores of ≥4, there was no difference in 28-day mortality between combination and single therapy (25.6% [23 of 90] versus 27.8% [22 of 79]; adjusted HR, 0.87; 95% CI, 0.47 to 1.62; P = 0.660). These findings were consistent for 14-day all-cause mortality. In this large cohort, we found for the first time that combination therapy with beta-lactams and fluoroquinolones was associated with a reduction in 28-day all-cause mortality among less severely ill patients with bacteremia caused by gram-negative bacilli.