A midline catheter is a peripheral IV catheter because the tip does not terminate in the central circulation. Midline catheters are greater than three inches in length and the tip terminates in the axillary vein of the upper arm. The use of a midline catheter for continuous vesicant infusions is not recommended. The infusion of IV push or intermittent vesicant infusions via a midline catheter is controversial. This is due to the potential for undetected extravasation as a result of where the tip terminates.  

 The use of a midline catheter is contraindicated in the following situations (page 38 of the Access Device Standards of Practice for Oncology Nursing):  

• Continuous infusion of vesicants 
• Infusates with a pH less than 5 or greater than 9 
• Parenteral nutrition 
• Solutions with glucose concentration greater than 10%
• Solutions with protein concentration greater than 5% 
• Solutions with osmolarity greater than 900 mOsm/L 

References: 

Camp-Sorrell, D., & Matey, L. (Eds.). (2017). Access device standards of practice for oncology nursing. Pittsburgh, PA: Oncology Nursing Society