Accuracy of point of care ultrasound to identify the source of infection in septic patients: a prospective study

Sepsis is a rapidly evolving disease with a high mortality rate. The early identification of sepsis and the implementation of early evidence-based therapies have been recognized to improve outcome and decrease sepsis-related mortality. The aim of this study was to compare the accuracy of the standard diagnostic work-up of septic patients with an integrated approach using early point of care ultrasound (POCUS) to identify the source of infection and to speed up the time to diagnosis. We enrolled a consecutive sample of adult patients admitted to the ED who met the Surviving Sepsis Campaign (SSC) criteria for sepsis. For every patient, the emergency physician was asked to identify the septic source after the initial clinical assessment and after POCUS. Patients were then addressed to the standard predefined work-up. The impression at the initial clinical assessment and POCUS-implemented diagnosis was compared with the final diagnosis of the septic source, determined by independent review of the entire medical record after discharge. Two hundred consecutive patients entered the study. A final diagnosis of the septic source was obtained in 178 out of 200 patients (89 %). POCUS-implemented diagnosis had a sensitivity of 73 % (95 % CI 66–79 %), a specificity of 95 % (95 % CI 77–99 %), and an accuracy of 75 %. Clinical impression after the initial clinical assessment (T0) had a sensitivity of 48 % (CI 95 % 41–55 %) and a specificity of 86 % (CI 95 % 66–95 %). POCUS improved the sensitivity of the initial clinical impression by 25 %. POCUS-implemented diagnoses were always obtained within 10 min. Instead the septic source was identified within 1 h in only 21.9 % and within 3 h in 52.8 % with a standard work-up. POCUS-implemented diagnosis is an effective and reliable tool for the identification of septic source, and it is superior to the initial clinical evaluation alone. It is likely that a wider use of POCUS in an emergency setting will allow a faster diagnosis of the septic source, leading to more appropriate and prompt antimicrobial therapy and source control strategies.