Microbiological findings in emergency department patients with sepsis identified by the Sepsis-3 criteria: a single-center prospective population-based cohort study

Background Studies comparing the microbiological profiles among sepsis patients identified with either Sequential Organ Failure Assessment (SOFA) score or systemic inflammatory response syndrome (SIRS) criteria are limited. The aim was to examine if there are differences in the microbiological findings among septic patients identified by Sepsis-3 criteria compared to patients identified by the previous sepsis criteria, SIRS, and without organ failure. A secondary purpose was to examine if we could identify microbiological characteristics with increased risk of 28-day mortality. Methods Prospective cohort study of all adult (≥ 18 years) patients admitted with sepsis to the Emergency Department of Slagelse Hospital, Denmark from 1st October 2017 to 31st March 2018. Information regarding microbiological findings was obtained via linkage between a sepsis database and the local microbiological laboratory data system. Data regarding 28-day mortality were obtained from the Danish Civil Registration System. We used logistic regression to estimate the association between specific microbiological characteristics and 28-day mortality. Results A total of 1616 patients were included; 466 (28.8%; 95% CI 26.6%-31.1%) met SOFA criteria, 398 (24.6%; 95% CI 22.5–26.8%) met SIRS criteria. A total of 127 patients (14.7%; 95% CI 12.4–17.2%) had at least one positive blood culture. SOFA patients had more often positive blood cultures compared to SIRS (13.9% vs. 9.5%; 95 CI on difference 0.1–8.7%). Likewise, Gram-positive bacteria (8.6% vs. 2.8%; 95 CI on difference 2.8–8.8%), infections of respiratory origin (64.8% vs. 57.3%; 95 CI on difference 1.0–14%), Streptococcus pneumoniae (3.2% vs. 1.0%; 95% CI on difference 0.3–4.1) and polymicrobial infections (2.6% vs. 0.3% 95 CI on difference 0.8–3.8%) were more common among SOFA patients. Polymicrobial infections (OR 3.70; 95% CI 1.02–13.40), Staphylococcus aureus (OR 6.30; 95% CI 1.33–29.80) and a pool of “other” microorganisms (OR 3.88; 95% CI 1.34–9.79) in blood cultures were independently associated with mortality. Conclusion Patients identified with sepsis by SOFA score were more often blood culture-positive. Gram-positive pathogens, pulmonary tract infections, Streptococcus pneumoniae, and polymicrobial infections were also more common among SOFA patients. Polymicrobial infection, Staphylococcus aureus, and a group of other organisms were independently associated with an increased risk of death.