Bacteremia in Trauma: A Contemporary Analysis of Blood Culture Results and Outcomes in 158,884 Patients.

Background: Bacteremia is a potentially lethal complication. Limited research exists describing its incidence and associated outcomes in trauma patients. This descriptive study characterized the incidence, risk factors, and outcomes of bacteremia in trauma patients. Methods: This study used 2017-2020 system-wide Trauma Registry/Electronic Data Warehouse to select trauma activations aged ≥18 years. Blood culture information, including pathogen genera and species, was obtained from electronic laboratory records. Bacteremia positive was defined as two blood cultures within two hours of each other, growing the same organism; bacteremia negative as no growth, only one blood culture with growth, or growth of two different organisms. Bacteremia-positive and bacteremia-negative patients were compared with patients without blood cultures. Logistic regression compared blood culture results with outcomes, adjusting for age, gender, Injury Severity Score (ISS), and comorbidities. Results: Of 158,884 patients at 89 centers, 17,166 (10.8%) had blood cultures. Of those with blood cultures, 1214 were bacteremia positive (7.1%). Compared with no blood cultures, bacteremia-positive patients were more likely male, with higher ISS, and more comorbidities and intensive care unit use. Bacteremia-positive patients were more likely to die (adjusted odds ratio [aOR], 3.78; 95% confidence interval [CI], 3.17-4.51; p < 0.001) and have severe sepsis/septic shock (aOR, 114.91; 95% CI, 95.09-138.85; p < 0.001). Most common isolates were Staphylococcus epidermidis (14%), non-methicillin resistant Staphylococcus aureus (12%), and Escherichia coli (6%), with highest mortality associated with Pseudomonas aeruginosa (45%), Enterococcus faecalis (30%), and Escherichia coli (28%). Conclusions: Bacteremia in trauma is uncommon (<1%) but associated with increased resource use and poorer outcomes. Bacteremia, or suspicion thereof, identifies a high-risk population and justifies aggressive empiric intervention to maximize survival.