Clinical Application of Midline Catheters in an Acute Care Ward: A Single-center Retrospective Observational Study

Midline catheters are a promising alternative to central venous access devices for intermediate-term therapy, with reduced risks of catheter-related bloodstream infections (CRBSI) and deep vein thrombosis (DVT). Their inclusion in the 2024 World Health Organization guidelines reflects increasing global interest. However, their use remains limited to select countries, and real-world clinical data are scarce. This study evaluated the safety and effectiveness of midline catheters in an acute care setting.

We retrospectively analyzed 68 midline catheter insertions in 50 patients between November 2023 and April 2024 in a general internal medicine ward of a 400-bed hospital. Collected data included patient demographics, indications for use, catheter dwell time, number of blood draws, and occurrence of complications. Insertions were ultrasound-guided and performed under sterile precautions. Weekly site disinfection and dressing changes were implemented. Complications were classified as major (CRBSI, symptomatic DVT) or minor (occlusion, poor return, leakage, unintentional removal).

Median age was 59.5 years (IQR 70-85.75); 46 % were female. All patients required frequent blood sampling. Common indications included prolonged antibiotic therapy (72 %) and difficult venous access (38 %). Median dwell time was 11 days, with a median of 4 blood draws. No CRBSI or symptomatic DVT occurred. Minor complications included leakage (n = 7), unintentional removal (n = 8), poor return (n = 4), and occlusion (n = 1).

Midline catheters demonstrated a favorable safety profile, with no major complications and minor complication rates comparable to international data. Preventive strategies should target vulnerable patients to reduce unintentional catheter removal.