Mortality and prognostic factors of patients who have blood cultures performed in the emergency department: a cohort study

Abstract

Background: Early identification and treatment of patients with severe infection improve their prognosis. The aims of this study were to describe the 30-day mortality and to identify prognostic factors among blood-cultured patients in a medical emergency department (MED).

Patients and methods: This was a hospital-based cohort study including all adult (≥15 years old) blood-cultured patients at the MED at Odense University Hospital between 1 August 2009 and 31 August 2011.

Results: During the study period, 5499/11 988 (45.9%) patients had blood cultures performed within 72 h of arrival and were included in the study. Of those included, 2631 (47.8%) were men, median age 69 years (range 15-103), and 418 (7.6%) were diagnosed with bacteraemia. The overall 30-day mortality among blood-cultured patients was 11.0% (10.2-11.9). In a multivariate Cox regression model, age of more than 80 years [hazard ratio (HR) 4.6 (95% CI 3.6-6.0)], at least two organ failure [HR 3.6 (2.9-4.5)], bacteraemia [HR 1.4 (1.1-1.8)], Charlson Comorbidity Index of at least 2 h [HR 1.7 (1.3-2.0)], SIRS [HR 1.5 (1.2-1.7)], a history of alcohol dependency [HR 1.7 (1.3-2.3)] and late drawing of blood cultures 24-48 h after arrival [HR 1.7 (1.3-2.2)] were found to be prognostic factors of mortality among blood-cultured patients in the MED.

Conclusion: Among blood-cultured patients in the MED, we found an 11.0% overall 30-day mortality. Factors associated with 30-day mortality were age more than 80 years, at least two organ failure, bacteraemia, Charlson Comorbidity Index of at least 2, SIRS, a history of alcohol dependency and late drawing of blood cultures.