Q&A: PICC vs Midline

Q: What is difference between picc line and midline. How can you tell the difference if one is not the one who inserted it?

A: By definition, the difference is:

PICC is short for peripherally inserted central catheter. It is a central vascular access device inserted into an extremity and advanced in the venous system until the distal tip is positioned in the vena cava.

Midline (ML) catheter is a vascular access device measuring 8 inches or less with the distal tip dwelling in the basilic, cephalic, or brachial vein, at or below the level of the axilla, and distal to the shoulder.

By just looking at the insertion site is, it is sometimes difficult to tell the difference. Both are vascular access devices inserted in the upper extremity , usually around the antecubital area or area above it.  However, by looking closely at the external part of catheter or hub, it is usually labeled as either “PICC” or “ML”.  PICCs that are power injectable are clearly marked “power injectable” and have a maximum flow rate printed on the catheter lumen or hub itself.

One important and biggest difference between the two is where the distal tip ends. The PICC tip ends in the distal third of the SVC making it a central venous access device. The ML tip ends in a peripheral vein, therefore it is considered a “peripheral device” and is not a central line.  The insertion site maybe in the extremity, near or at the antecubital fossa, the catheter label may say “PICC” but if the tip, as determined by x-ray is not in the distal tip of the SVC, it is not considered a central line.

If you are not the one who inserted the line, it is recommended to look for the insertion documentation record or device placement information, including xray results for tip confirmation to determine what kind of catheter it is. In addition, many of the catheter device manufacturers have “medical alert” card for patients to keep. This medical alert card has information about the patient’s implanted vascular access device and other pertinent information.

Understanding the difference between the two vascular access devices and knowing where the tip of your patient’s catheter is positioned are key information for positive outcomes when caring for patients with vascular access devices.