Blood culture sampling in the central emergency room of the Department of Internal Medicine at Frankfurt am Main Northwest Hospital

The central emergency room is often the first point of contact for patients seeking microbiological diagnostics and anti-infective therapy. Blood cultures (BC) are currently (2025) the gold standard for pathogen diagnostics in human blood. In this retrospective study, staff training and the establishment of a standard operating procedure (SOP) for the collection of BC pairs were intended to achieve an adequate number of BC pairs collected (≥2 BC pairs), a reduction in the contamination rate, and a reduction in false-positive BC pairs in internal medicine patients who received anti-infective therapy in the central emergency room. The retrospective evaluation was conducted over three months (July–September) in 2024 and 2025. In June 2025, the SOP was established and staff training was conducted. A total of 325 patients were included in the comparison period (2024) and 289 patients in the intervention period (2025). It was shown that there was a significant increase (p=0.001) of 45.86% in adequately collected BC pairs (≥2 BC pairs) during the intervention period (2025). Furthermore, the intervention period (2025) showed a significant decrease (p=0.001) of 8.81% in inadequately collected BC pairs (<2) compared to the comparison period (2024). The contamination rate was reduced non-significantly (p<0.05) with p=0.010 from 13.37% (2024) to 7.52% (2025). Similarly, the proportion of false-positive BC pairs out of all positive BC pairs was reduced non-significantly (p=0.106) by 12.06% during the intervention period. This intervention study showed that staff training and an SOP for blood cultures can significantly improve microbiological preanalytics in terms of quality and quantity. This could contribute to improved patient care by avoiding unnecessary anti-infective therapies and enabling adequate pathogen diagnostics.