Midline Catheters Versus PICCs in Hospitalized Medicine Patients: Bloodstream Infection, Thrombosis, and Device Failure

Abstract

Peripherally inserted central catheters (PICCs) and midline catheters have become the main options for intermediate-term venous access in hospitalized medicine patients, yet the choice between them is often made by habit or local convention rather than evidence. Midlines have gained popularity as a safer alternative because their tip remains in a peripheral vein, which is expected to reduce bloodstream infection, but this assumption has rarely been weighed against their effects on thrombosis and device reliability. This review compares the two devices across bloodstream infection, catheter-related thrombosis, and device failure, drawing on comparative cohort studies, trials, meta-analyses, and clinical guidance published up to 2023, together with health systems, quality improvement, and supply chain literature that explains why device outcomes differ between hospitals. The evidence suggests that midlines reduce bloodstream infection and catheter occlusion when outcomes are counted per patient, although much of this advantage fades when risk is measured per catheter or per day of use, because midlines remain in place for shorter periods and their infections are less consistently captured by surveillance. In contrast, midlines carry a higher burden of superficial venous thrombosis, an equal or greater daily risk of deep vein thrombosis, and more frequent dislodgement, infiltration, and leakage, so they are more often removed before treatment is complete. The safety of either device therefore depends less on the device alone than on expected duration of therapy, the nature of the infusate, catheter size, and the quality of insertion, maintenance, surveillance, and supply in the hospital where it is used. Midlines are best suited to peripherally compatible therapy expected to last up to about two weeks, while PICCs remain preferable for longer courses and central-only treatments. Because the available evidence is largely observational and shaped by differences in patient selection, well-designed randomized trials are needed to guide device selection with greater confidence.