Safety and efficacy of midline catheters versus peripheral intravenous catheters : a pilot randomized controlled trial

Background: Despite pervasive need for peripheral intravenous catheters, insertion is often difficult, and approximately two thirds fail prematurely. Midline catheters are an alternative long peripheral catheter, inserted in the upper arm, ideal for patients with difficult access. Aim: The aim of this study is to test feasibility of the protocol and compare the efficacy and safety of midline catheters to peripheral intravenous catheters. Design: A parallel-group, pilot randomized controlled trial of adult medical/surgical hospitalized patients, from a single Australian referral hospital. Methods: Participants with difficult vascular access (≤2 palpable veins) and/or anticipated ≥5 days of peripherally compatible intravenous therapy were recruited between May 2019 and March 2020. Participants were randomized to (1) peripheral intravenous catheter or (2) midline catheter. Primary feasibility outcome measured eligibility, recruitment, protocol adherence, retention and attrition. Primary clinical outcomes measured device insertion failure and post-insertion failure. Results: In total, n = 143 participants (71 peripheral intravenous catheters and 72 midline catheters) were recruited; n = 139 were analysed. Most feasibility criteria were met. Peripheral intravenous catheters had shorter functional dwell time, with higher incidence of post-insertion failure compared to midline catheters. Conclusion: Midline catheters appear to be superior for patients with difficult vascular access or receiving prolonged intravenous therapy; a large, multi-centre trial to confirm findings is feasible.