R. Eleanor Anderson, MD, Ron M. Walls, MD, FRCPC, FAAEM

Fever, elevated CRP level, or SIRS criteria alone did not predict bacteremia, but when all three parameters were negative, bacteremia was present in fewer than 1% of patients. 

Researchers assessed the value of temperature, C-reactive protein (CRP) level, and systemic inflammatory response syndrome (SIRS) criteria (see table) for early identification of bacteremia in a population-based cohort study of more than 17,000 visits by adults to an emergency department in Denmark over a 2-year period.

Temperature, although one of the SIRS criteria, was analyzed separately as it is often the decisive factor for drawing blood cultures. Bacteremia was defined as a positive blood culture within the first 48 hours, elevated CRP was defined as a level >100 mg/L, and SIRS was considered present if two of four criteria were met.

Blood cultures were drawn for 46% of patients and were positive in 7.6% (corresponding to 3.5% of all patients). The most frequent pathogens were Escherichia coli (30%) and Streptococcus pneumoniae (13%); patients with these species were more likely to have elevated CRP and SIRS. Among bacteremic patients, 34% were normothermic on arrival, 33% had CRP <100 mg/L, and 28% had fewer than two SIRS criteria; however, only 5% had the combination of normal temperature, CRP <100 mg/L, and fewer than two SIRS criteria.

Citation(s):

Lindvig KP et al. How do bacteraemic patients present to the emergency department and what is the diagnostic validity of the clinical parameters; temperature, C-reactive protein and systemic inflammatory response syndrome? Scand J Trauma Resusc Emerg Med. 2014 Jul 15; 22:39.