Impact of irritating infusates via midline catheters on vascular complications: a multicentre prospective cohort study protocol in China.

Abstract

Midline catheters (MCs) longer than 15 cm are increasingly used for intravenous therapy. However, a consensus on the safe administration of irritating infusates (pH <5 or >9, osmolality >900 mOsm/L) is lacking. The current guidelines do not specify how the catheter tip position (axillary vein of the chest wall or subclavian vein) modulates the complication risks. This study investigates the relationship between the tip location, irritant drug properties and vascular injury. A multicentre, prospective study involving patients receiving irritating infusates via MCs across 12 Chinese hospitals (stratified random sampling of 12 provinces) will be conducted. Preinsertion ultrasound will assess the vascular anatomy, with postinsertion X-ray confirming the tip position. The primary outcome, intima injury, will be assessed through weekly ultrasound evaluations until catheter removal. Secondary outcomes include phlebitis, thrombosis, occlusion and infection. Associations among tip position, drug physicochemical properties, dwell time and complications will be analysed using multivariable logistic and Cox regression analyses. The study is approved by the Ethics Committee of the Sir Run Run Shaw Hospital, Zhejiang University School of Medicine (#20240096; 20/02/2024). Results will be disseminated through peer-reviewed publication and international conferences. NCT06454552; Pre-results.