Positive blood culture is not associated with increased mortality in patients with sepsis-induced acute respiratory distress syndrome

Abstract

Background and objective: Previous studies have demonstrated that positive blood culture could contribute to poorer outcomes in patients with pneumonia. However, the impact of positive blood culture on the outcomes of patients with sepsis-induced acute respiratory distress syndrome (ARDS) has not been evaluated.

Methods: An observational study that prospectively screened 4861 patients admitted to medical or surgical intensive care units (ICUs) of a tertiary referral centre was performed.

Results: Among 4861 admitted patients, 146 diagnosed with sepsis-induced ARDS were enrolled (mean age: 66.1 years). Lower PaO2 /FiO2 , decreased respiratory system compliance, and higher lung injury scores (LIS) on the day of ARDS diagnosis were associated with positive blood cultures (n = 68) rather than negative blood cultures (n = 78). There was no relationship between positive blood culture and in-hospital mortality. Kaplan-Meier estimates also revealed that positive blood culture was not associated with 60-day mortality but with an increased length of stay in the hospital and in the ICU (P = 0.007 and P = 0.016, respectively). Using multivariate logistic regression, higher LIS was independently associated with positive blood culture. In addition, chronic pulmonary disease, lower platelet count, higher LIS, and the development of shock on the diagnosis of ARDS, were independent risk factors for in-hospital mortality.

Conclusions: This study suggests that the presence of positive blood culture is not associated with increased mortality; however, the mean durations of hospital and ICU stays in patients with sepsis-induced ARDS are increased.

Keywords: acute respiratory distress syndrome; bacteraemia; infection and inflammation; lung injury; mortality.