Question the Default! Follow-up Blood Cultures for Gram Negative Rod Bacteremia and Other Matters

Question the default in clinical medicine, especially when the evidence is weak. Just in case we need reminding, within our specialty the majority of our guidelines are based on expert opinion or low quality evidence, as summarized here.

I really enjoyed this article in Clinical Infectious Diseases which suggested that follow up blood cultures on patients with gram negative rod (GNR) bacteremia are generally not needed. Kudos to the authors for attempting to address this in an empirical fashion. 

Certainly follow up blood cultures should not be definitively abandoned for patients with GNR bacteremia (particularly when resistant organisms are in the mix or when clinical response to therapy is not prompt) but we should question their routine value and acknowledge their potential harm (risk of contamination with gram positive skin commensals resulting in more antibiotic exposure). 

Why stop there? Why prescribe 14 days of antibiotics (instead of 5-7 days) for common infections? Why obtain urine cultures on febrile, catheterized patients when the risk of invasive infection from a urinary source is low (urine test stewardship)? Why use contact precautions for endemic MRSA and VRE control in the hospital when the quality of evidence is poor? The list goes on and on.

Question dogma.