Comparing the use of midline catheters versus peripherally inserted central catheters for patients requiring peripherally compatible therapies: A pilot randomised controlled trial (the compact trial).

Background: Midline catheter (MC) use has increased in acute-care settings, particularly for patients with difficult venous access or requiring peripherally compatible intravenous therapy for up-to 14 days. Our aim was to assess feasibility and generate clinical data comparing MCs with Peripherally Inserted Central Catheters (PICCs).

Methods: A two-arm parallel group pilot randomised controlled trial (RCT), comparing MCs with PICCs, was conducted in a large tertiary hospital in Queensland between September 2020 and January 2021. The primary outcome was study feasibility, measured against rates of eligibility (>75%), consent (>90%), attrition (<5%); protocol adherence (>90%) and missing data (<5%). The primary clinical outcome was all-cause device failure.

Results: In total, 25 patients were recruited. The median patient age was 59-62 years; most patients were overweight/obese, with ≥2 co-morbidities.

Primary Outcomes: The eligibility and protocol adherence criteria were not met; of 159 screened patients, only 25 (16%) were eligible, and three patients did not receive their allocated intervention post-randomisation (88% adherence). All-cause failure occurred in two patients allocated to MC (20%) and one PICC (8.3%).

Conclusions: Our study found that a fully powered RCT testing MCs compared with PICCs is not currently feasible in our setting. We recommend a robust process evaluation before the introduction of MCs into clinical practice.