Long peripheral cannulas (mini-midline) lend themselves very well to ultrasound-guided positioning in the deep veins of the arm or forearm in cases of DIVA.
Their length (6-15 cm) is associated with minimal risk of dislocation with respect to the short cannulas, as well as a longer duration. In the child, 3Fr catheter will preferably be used.
For a limited period of time (few days) both polyethylene and polyurethane catheters can be used, as well as PEBA. For longer durations, it is preferable to avoid mini-midlines in polyethylene, at greater risk of thrombotic events (mechanical thrombophlebitis, due to the rigidity of the material).
In terms of cost-effectiveness, at the moment it seems appropriate to prefer simple and low-cost mini-midlines to be inserted with the classic Seldinger technique (needle - metal guidewire - catheter) compared to more complex mini-midlines, more difficult to use and more expensive, such as those designed as coaxial devices 'all in one'.