The use of long-term peripheral venous catheters inserted in the upper limb (PICC lines and Midlines) has increased markedly over recent years.

Catheter-related bacteremias and venous thromboses are the main complications associated with these catheters. These events may occur independently or simultaneously. In addition, venous thromboses may involve the superficial venous system (SVT) or the deep venous system (DVT).

Current guidelines define septic thrombophlebitis as the association of a bacteremia and a DVT along the venous course of the catheter. This represents a severe complication of catheter-related bacteremia, leading to a modification in the duration of antibiotic therapy. However, SVTs associated with catheter-related bacteremias along the catheter pathway are not included in the definition of septic thrombophlebitis and are not addressed by specific recommendations.

The objective of this study is therefore to assess the impact of upper-limb SVT on the frequency of unfavorable outcomes in catheter-related bacteremias related to PICC and Midline catheters, in order to determine whether superficial venous thrombosis occurring in the context of a catheter-related bacteremia should be considered a distinct entity not falling under the diagnosis of septic thrombophlebitis (and therefore not requiring a modification of antibiotic treatment duration, in accordance with current guidelines), or whether, conversely, it should be considered equivalent to septic thrombophlebitis, as is the case for deep venous thrombosis.

Inclusion Criteria:

• Age ≥ 18 years
• Hospitalization in a department of Nice University Hospital
• Expected length of hospitalization ≥ 72 hours
• Diagnosis of catheter-related bacteremia on PICCline or Midline.
• Affiliation with a social security system
• No objection to the study

Exclusion Criteria:

• Pregnant or breastfeeding women
• Legal protection measures (patients under guardianship, trusteeship, or judicial protection)
• Inability to remove the catheter
• Doppler ultrasound showing DVT in the upper limb at selection.
• Inability to perform the initial routine Doppler ultrasound
• Withdrawal of the patient's consent