Shirin Towfigh

Research from JAMA Surgery — Significant Reduction of Wound Infections With Daily Probing of Contaminated Wounds — A Prospective Randomized Clinical Trial

Acute respiratory distress syndrome (ARDS) has been shown to increase morbidity but not mortality in trauma patients; however, little is known about the effects of ARDS in nontrauma surgical patients. The purpose of this study is to evaluate the risk factors for and outcomes of ARDS in nontrauma surgical patients. A prospective observational study was performed in the surgical intensive care unit (ICU) of an academic tertiary care center. From 2000 to 2005, all nontrauma surgical admissions to the surgical ICU were evaluated daily for ARDS based on predefined diagnostic criteria. Logistic regression analysis identified independent predictors for ARDS and ICU mortality. Of 2,046 patient identified, 125 (6.1%) met criteria for ARDS. The incidence of ARDS declined annually from 12.2% to 2.1% during the study period (p < 0.001). ARDS patients were significantly older (55.4 years vs. 51.8 years, p = 0.014) and more likely to be obese (32% vs. 22%, p = 0.007) than the non-ARDS population. Independent predictors of ARDS included use of pressors (relative risk, RR = 3.30), sepsis (RR = 1.72), and body mass index >or=30 kg/m (RR = 1.57). Independent predictors of ICU mortality included ARDS (RR = 6.88), pressors (RR = 2.85), positive fluid balance (RR = 2.27), Acute Physiology and Chronic Health Evaluation II (RR = 1.04), and age (RR = 1.02). Unlike trauma patients, ARDS was an independent predictor of ICU mortality in nontrauma surgical patients, independent of age and disease severity. Nontrauma surgical patients who developed ARDS were older, sicker, and had a longer ICU stay. Independent predictors of ARDS included use of pressors, sepsis, and obesity.

Background: The designation “gram-positive bacillus” includes a variety of pleomorphic microorganisms, including diphtheroids, coryneform species, coccobacilli, and other small rods. Despite differing greatly in their virulence, sources, and even genus, these microscopically similar organisms are often difficult to differentiate without genetic testing. Methods: We present a patient with necrotizing fasciitis and a review of the literature to exemplify and assess the scope of this diagnostic conundrum. Cultures taken intra-operatively during surgical debridement grew Morganella morganii and “diphtheroids.” Given the low virulence of both organisms, the diphtheroids were reexamined microscopically and assayed for enzymatic activity. Genetic sequence analysis of 16S ribosomal ribonucleic acid (rRNA) was required for species identification. Results: Microscopic inspection identified small, non-spore-forming, gram-positive rods, arranged in clusters, that formed circular, smooth colonies. These were facultatively anaerobic, catalase-negative, non-hemolytic, and unable to reduce nitrates. Standard techniques and assays were unable to identify our organism to species. Ultimately, 16S rRNA gene sequencing of 833 base pairs achieved a 99.04% species match to Arcanobacterium bernardiae . Conclusion: At our facility, diphtheroids are generally considered non-pathogenic contaminants in skin and soft tissue infections. The finding of A. bernardiae in necrotizing fasciitis is unusual and clinically important but would have been missed using conventional methods. As the “gram-positive bacillus” comes to include an ever-increasing number of organisms, genetic sequencing will probably be required more regularly for species identification. Furthermore, given that these genera are similar, often mistaken as contaminants, and difficult to differentiate using standard assays, they may often be missed and are possibly a more-frequent cause of complicated skin and soft tissue infections than the literature would suggest.

Research from JAMA Surgery — Significant Reduction in Incidence of Wound Contamination by Skin Flora Through Use of Microbial Sealant