Selective use of blood cultures in emergency department pneumonia patients.

Our objectives were to identify factors associated with positive blood cultures and to evaluate blood culture use in the management of hospitalized pneumonia patients to limit their use. A retrospective chart review was conducted at a community teaching hospital. Emergency Department patients with an admission diagnosis of pneumonia during calendar years 2001-2002 were included. Patients younger than age 18 years and those with a non-pneumonia discharge diagnosis were excluded. Of 684 eligible patients, 23 (3.4%) had true positive blood cultures. All organisms were sensitive to empiric antibiotics. Three risk factors were associated with positive blood cultures: oxygen saturation < 90%, serum sodium < 130 and respiratory rate > 30 breaths/min. No patient had antibiotic coverage broadened based on blood culture results. Positive blood culture rates were low and did not affect the clinical management of pneumonia patients. We recommend eliminating blood cultures in community-acquired pneumonia (CAP) patients, but obtaining blood cultures in patients at risk for multi-drug resistant pathogens, such as health-care-associated pneumonia (HCAP) patients.