5: Back to bacteraemia

Bacteremia represents the presence of bacteria within the bloodstream, serving as a critical indicator of systemic infection and a failure of local immune control. Pathogens typically enter the blood by breaching physical barriers such as the skin, lungs, or gut, often exploiting tissue trauma or synergistic infections like influenza. Diagnostic accuracy relies on blood cultures, which require optimal volume—ideally three sets—to maximize sensitivity for low-level bacteremia. While traditional protocols advocate for different puncture sites, the primary goal remains capturing the organism before the administration of broad-spectrum antimicrobials, which can rapidly render cultures negative. Management necessitates selecting antibiotics with appropriate pharmacokinetics, such as high protein binding or intravenous administration, to ensure sufficient blood concentrations. Ultimately, identifying the specific pathogen allows clinicians to anticipate the natural history of the infection, manage potential metastatic complications, and ensure effective source control.