Jacobs Journal of Emergency Medicine

The Yield of Blood Cultures Drawing among Discharged Patients from Emergency Departments with Positive Blood Cultures

Published on: 2017-05-26



Occult bloodstream infection (OBSI) is unnoticed in adults. The clinical relevance of OBSI was examined in a few studies while all of them showing no cost-effectiveness in withdrawing blood cultures from patients discharged from emergency departments(ED’s). We investigated the characteristics and outcome of patients who were discharged from the ED and have positive blood cultures.

Material and Methods

All files of patients with positive blood cultures in one ED seeing 170000 patients a year between 2011-2013 were screened. The main outcomes examined in our retrospective study were: mortality in 28 days among patients discharged from ED with positive cultures, the readmission rate in the first week and the rate of change in the antibiotic treatment policy by the ED team or the community health services.


During the three years, 157 patients who were discharged from the ER had positive blood cultures. 39% had true clinical significance (Group A) and 61% of the positive blood cultures could be considered as contaminated (Group B). There was no difference between those two groups according to the mortality rate in 30 days, demographic characteristics, the vital signs in applying ED, laboratory results. We found that the rate of true cultures was significantly higher among patients with comorbidities as diabetes mellitus and cancer and among patient with polypharmacy treatment.


The results may indicate that there is a worse prognosis for patients discharged from ED with true positive cultures and due to careful management of these cultures results and preventive strategies such as high rate of changing the antibiotic treatment policy, high rate of re-admission, and high rate of hospitalization, the dangers were abolished. In our research co-morbidities such as diabetes mellitus, cancer and poly-pharmacy were found to be predicting factors for positive blood cultures, but they had no prognostic value. 


Emergency Medicine Department, Blood Cultures, Discharge, Bacteremia