Inadequacy of temperature and white blood cell count in predicting bacteremia in patients with suspected infection

Background: Early treatment of sepsis in Emergency Department (ED) patients has lead to improved outcomes, making early identification of the disease essential. The presence of systemic inflammatory response criteria aids in recognition of infection, although the reliability of these markers is variable.

Study objective: This study aims to quantify the ability of abnormal temperature, white blood cell (WBC) count, and bandemia to identify bacteremia in ED patients with suspected infection.

Methods: This was a post hoc analysis of data collected for a prospective, observational, cohort study. Consecutive adult (age ≥ 18 years) patients who presented to the ED of a tertiary care center between February 1, 2000 and February 1, 2001 and had blood cultures obtained in the ED or within 3 h of admission were enrolled. Patients with bacteremia were identified and charts were reviewed for presence of normal temperature (36.1-38°C/97-100.4°F), normal WBC (4-12 K/μL), and presence of bandemia (> 5% of WBC differential).

Results: There were 3563 patients enrolled; 289 patients (8.1%) had positive blood cultures. Among patients with positive blood cultures, 33% had a normal body temperature and 52% had a normal WBC count. Bandemia was present in 80% of culture-positive patients with a normal temperature and 79% of culture-positive patients with a normal WBC count. Fifty-two (17.4%) patients with positive blood cultures had neither an abnormal temperature nor an abnormal WBC.

Conclusion: A significant percentage of ED patients with blood culture-proven bacteremia have a normal temperature and WBC count upon presentation. Bandemia may be a useful clue for identifying occult bacteremia.