Do We Really Need Blood Cultures in Treating Patients with Community-acquired Pneumonia?

Objectives: Positive blood cultures (BC) are considered a gold standard specific test for diagnosing and managing patients with community-acquired pneumonia (CAP). The aims of this study were to determine the positivity rate of BCs performed in patients with CAP, empirically started antibiotic regimens and conformity of the empirically started antibiotics with the results of BCs.

Methods: Patients with the diagnosis of CAP with started empiric antibiotic treatment and performed BC test were included in the study. The BC set consisting of aerobic/anaerobic bottles was obtained from a single draw. Co-morbidities of patients, empirically started antibiotics and BC results were noted. Empiric antibiotics were checked as to whether they conform to BC results.

Results: The study included 262 patients with CAP. Majority of BC sets (195) revealed no bacterial growth. Of the total 262 sets of BCs, 67 (25.6%) sets displayed growth of organism and only 30 sets (11.5%) represented significant isolates. Commonly isolated microorganisms were Escherichia coli, Streptococcus species and Staphylococcus species. Ampicillin/Sulbactam and Fluoroquinolone combination was the leading antibiotic regimen chosen for the treatment (54.2%). The majority of patients had at least one co-morbidity. Ninety-six patients (37%) had a pulmonary disease, 74 (29%) had a malignancy, 74 (29%) had heart failure and 67 (26%) suffered from diabetes.

Conclusion: Significantly positive results are rare (11.5%) and majority of blood cultures revealed negative results. BC tests may not be performed in all patients with CAP (Tab. 3, Ref. 11). Full Text (Free, PDF) www.bmj.sk.