Blood cultures on internal medicine: utilization profile and clinical implications

Resumen

Introduction: recent literature suggests that excessive use of blood cultures could prolong length of stay and hospital costs. Moreover, low positive rates have been reported and positivity predictive scores have recently been proposed. Methods: we conducted an observational prospective study in an Internal Medicine department of a university reference hospital analysing data from all patients to whom BC was requested. Results: blood cultures were performed in 39.9% of 414 admissions. Patients with blood cultures had higher length of stay and underwent more laboratory and imaging diagnostic tests. Global positivity rate was of 7.5%. Patients fulfilling sepsis criteria had a higher positivity rate (21.7%) and there were no positive blood cultures in patients without sepsis, namely in cases of isolated creactive protein elevation, leucocytosis or fever. In addition, blood cultures results were not a determinant of antibiotic adjust or de-escalation. Conclusions: our data suggest that the use of BC should be done essentially in patients with sepsis criteria, reducing its unnecessary use, although more studies are required to validate such practice.