Even before the current COVID-19 pandemic, community acquired pneumonia (CAP) had a huge impact in health systems around the world [1]. Despite the availability of vaccinations, the incidence of this condition can range from 20 to 70 cases for every 10,000 patients depending on the country [[2], [3], [4], [5]]. Besides vaccinations, prompt initiation of antibiotics, identification of the etiologic agent and improvements in other supportive treatments (e.g., respiratory assistive devices) could also have an impact on mortality in CAP [1,6,7].

Identifying the etiologic organism has been one of the biggest challenges in the treatment of CAP, the causative agent remains unknown in 50%–70% of cases [2,3,[8], [9], [10], [11]] despite using different specimen sources. It is for this reason, that CAP management guidelines have changed their recommendations on this matter over the years, addressing advances in microbiological techniques with the goal of recommending tests only in useful circumstances based on risk factors, the need for intensive care unit (ICU) level of care and/or severity of the pneumonia [6,12,13].

Some studies have shown that bacteremia in CAP can be associated with worse outcomes and increased mortality and early identification of the infectious agent can lead to more consistent antibiotic treatment which justifies the use of blood cultures in this diagnostic process [15,16]. Conversely, other studies have failed to show any difference in outcomes and/or advantages in antibiotic management related to the use of blood cultures while this practice increases costs [5,[17], [18], [19]].

Given these discordant findings, the Infectious Diseases Society of America (IDSA) on their most recent CAP guidelines recommended the use of blood cultures only in specific scenarios, including when patients have severe pneumonia (based on validated severity scores), require ICU admission, or have a history of infections with multidrug resistant organisms (MDRO) [13]. Based on this premise, we conducted a study to evaluate risk factors of mortality and increased length of stay in our health center, with particular interest on the relationship between appropriateness of blood cultures use according to three guideline supported indications/criteria.