Relationship between the time to positivity of blood culture and mortality according to the site of infection in sepsis

ABSTRACT

OBJECTIVE: The time to positivity (TTP) of blood culture reflects bacterial load and has been reported to be associated with outcome in bloodstream infections. This study was performed to evaluate the relationship between the TTP of blood culture and the mortality rates associated with sepsis and septic shock according to the site of infection. METHODS: We performed a retrospective cohort study on patients with sepsis and septic shock. The rates of blood culture positivity and mortality as well as the relationship between the TTP and 28-day mortality rate were compared among patients with different sites of infection, such as the lungs, abdomen, urogenital tract, and other sites. RESULTS: A total of 2,668 patients were included, and the overall mortality rate was 21.6%. The rates of blood culture positivity and mortality were different among the different infection sites. There was no relationship between the TTP and mortality rates of total, lung, and urogenital infections. Patients with abdominal infections showed a negative correlation between the TTP and 28-day mortality rate. In patients with abdominal infections, a TTP < 20 hours was independently associated with 28-day mortality compared with patients with negative blood culture (hazard ratio, 1.73; 95% confidence interval, 1.16–2.58). However, there was no difference in mortality rates of patients with a TTP≥20 hours and a negative blood culture. CONCLUSION: The shorter TTP in patients with abdominal infections in sepsis and septic shock was associated with a higher 28-day mortality rate.