Between 15 and 30% of all nosocomial bacteremias and sepsis are associated with the use of intravascular devices. Catheter-related bloodstream infections (CRBI) are infections in which the organism identified in the blood is also present on the tip of the catheter itself or in a blood sample taken through it. The aim of the study was to evaluate the role of ultrasound in the diagnosis of infections related to the use of central catheters.
Between January 2018 and June 2019, we carried out a prospective study on 36 patients with a central catheter, such as a central venous catheter (CVC), a central catheter with peripheral insertion (PICC), or a fully implanted central venous catheter (PORT-a-cath) and who had signs and symptoms of infection. These patients were submitted to an ultrasound of the catheter upon arrival in the ward in case of suspected infection, or at the time of the onset of signs and symptoms of infection (if these arose during hospitalization). Patients with a central catheter but without signs and symptoms of infection were not included in the study. The end point of the study was to evaluate sensitivity (SENS), specificity (SPEC), positive and negative predictive value (PPV-NPV) and overall diagnostic accuracy (ODA) of ultrasound in the diagnosis of CRBI through Receiver Operating Characteristic (ROC) curve analysis.
US showed a SENS of 94%, a SPEC of 84%, a PPV of 84%, an NPV of 94% and an ODA of 88.8% for the diagnosis of CRBI.
Preliminary data from our study show that US of intravascular devices has a high SENS and SPEC in the diagnosis of CRBI, and can, therefore, be used as a valid tool to decide whether to remove the device early or leave it in place.