Ultra long peripheral catheter versus accelerated Seldinger technique long peripheral catheter in difficult intravenous access patients (ULAST): a pragmatic randomised controlled trial protocol.

introductionUltrasound-guided peripheral cannulation by specialised nurses is increasingly used to improve first-stick success rates in patients with difficult intravenous access (DIVA). Long peripheral catheters are indicated for extended dwell times and the reduction of central venous catheters and their associated complications. Recently, multiple types of catheters and insertion techniques have been used in clinical care. METHODS AND ANALYSIS: This prospective, two-arm, single-centre, non-blinded, pragmatic randomised controlled trial will compare two types of long peripheral catheters. A 63 mm ultra-long peripheral catheter using the catheter-over-needle approach will be compared with an 80-100 mm accelerated Seldinger technique-long peripheral catheter, which is the standard of care. Adult inpatients with DIVA, requiring a long peripheral catheter, will be included. The study aims to compare the mean dwell time, therapy completion rates and incidences of catheter-related thrombosis, infections, phlebitis, infiltration, loss of catheter usability and unplanned removal among adult DIVA patients. A priori sample size calculation based on average dwell times from published studies indicates that a minimum of 52 patients (26 per group) is needed. Consecutive sampling will be used until the sample size is reached. Upon signing the informed consent form, patients will be randomised in a 1:1 ratio using sequentially numbered, opaque, sealed envelopes. Due to the distinct visual differences between the two types of long peripheral catheters, blinding the inserter during the procedure is impractical. ETHICS AND DISSEMINATION: The ethics committee of Ghent University (B6702024000487) and University Hospital of Brussels approved this study. On completion of the study, results will be disseminated via publication in a relevant peer-reviewed scientific journal. No external funding was received for the execution of this trial. The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER: NCT07005310. PROTOCOL VERSION: Version 1, 17/03/2025.