Resumen de Predictores clínicos de bacteriemia en adultos inmunocompetentes hospitalizados por neumonía adquirida en la comunidad
Fernando Saldías P, Tomás Reyes B, Josefina Sáez Binelli, Carmen Rain M, Pamela Illanes C, Catalina Briceño V, Orlando Díaz
Background: The clinical usefulness of blood cultures in the management of patients hospitalized with community-acquired pneumonia (CAP) is controversial. Aim: To determine clinical predictors of bacteremia in a cohort of adult patients hospitalized for community-acquired pneumonia. Material and Methods: A prospective cohort of 605 immunocompetent adult patients aged 16 to 101 years (54% male) hospitalized for CAP was studied. The clinical and laboratory variables measured at admission were associated with the risk of bacteremia by univariate and multivariate analysis using logistic regression models. Results: Seventy seven percent of patients had comorbidities, median hospital stay was 9 days, 7.6% died in hospital and 10.7% at 30 days. The yield of the blood cultures was 12.6% (S. pneumoniae in 69 patients, H. influenzae in 3, Gram negative bacteria in three and S. aureus in one). These results modified the initial antimicrobial treatment in one case (0.2%). In a multivariate analysis, clinical and laboratory variables associated with increased risk of bacteremia were low diastolic blood pressure (Odds ratio (OR): 1.85, 95% confidence intervals (CI) 1.02 to 3.36, p < 0.05), leukocytosis e" 15,000/mm³ (OR: 2.18, 95% CI 1.22 to 3.88, p < 0.009), serum urea nitrogen e" 30 mg/dL (OR: 2.23, 95% CI 1.22 to 4.05, p < 0.009) and serum C-reactive protein e" 30 mg/dL (OR: 2.20, 95% CI 1.22 to 3.97, p < 0.01). Antimicrobial use before hospital admission significantly decreased the blood culture yield (OR: 0.14, 95% CI 0.04 to 0.46, p < 0.002). Conclusions: Blood cultures do not contribute significantly to the initial management of patients hospitalized for community-acquired pneumonia. The main clinical predictors of bacteremia were antibiotic use, hypotension, renal dysfunction and systemic inflammation.
