What is the difference between midline (peripherally inserted central catheter) and PICC (Peripherally Inserted Central Catheter) lines for intravenous access?

From the Guidelines

Midline catheters are preferred over PICC lines for intermediate-term therapy (6-14 days) for peripherally compatible infusions, whereas PICC lines are more suitable for long-term complex treatments or irritant/vesicant infusions. The main difference between midline catheters and PICC lines is their placement location within the vascular system. A midline catheter is a shorter peripheral catheter that extends from the insertion site into the larger veins of the arm but stops short of the central vasculature, terminating below the axilla in the basilic or cephalic vein. In contrast, a PICC line is longer and extends all the way into the central venous system, with its tip typically positioned in the lower third of the superior vena cava near the junction with the right atrium. According to the Michigan Appropriateness Guide for Intravenous Catheters (MAGIC) study 1, midline catheters and ultrasonography-guided peripheral intravenous catheters were preferred to PICCs for use between 6 and 14 days. This study evaluated 665 scenarios and rated the appropriateness of PICC use compared to other venous access devices, including midline catheters. The study found that PICC use was rated as inappropriate when the proposed duration of use was 5 or fewer days, and midline catheters were preferred for intermediate-term therapy. Some key points to consider when choosing between midline and PICC lines include:

• Expected duration of therapy: Midline catheters are suitable for intermediate-term therapy (2-4 weeks), while PICC lines can remain in place for months.
• Medication properties: Midlines cannot be used for vesicant medications, solutions with extreme pH, or parenteral nutrition, whereas PICC lines are appropriate for all types of infusions.
• Vascular access needs: PICC lines offer more versatility for long-term complex treatments, but require more specialized training to insert and have a higher risk of serious complications. Overall, the choice between midline and PICC lines depends on the individual patient's needs and the specific clinical scenario, and should be guided by evidence-based criteria such as those outlined in the MAGIC study 1.

From the Research

Midline vs PICC Lines

• Midline catheters and Peripherally Inserted Central Catheters (PICCs) are both used for intravenous access, but they have distinct differences in terms of their insertion, use, and complications 2, 3, 4, 5, 6.
• Midline catheters are typically shorter than PICCs, ranging from 10 to 25 cm in length, and are inserted into a peripheral vein, usually in the arm 3, 6.
• PICCs, on the other hand, are longer and are inserted into a central vein, usually in the neck or chest 2, 5.

Indications and Use

• Midline catheters are often used for short-term intravenous therapy, typically for less than 14 days, and are an alternative to PICCs for patients with difficult vascular access or those requiring antibiotic therapy 2, 4.
• PICCs are used for longer-term intravenous therapy, often for several weeks or months, and are commonly used for patients requiring total parenteral nutrition, chemotherapy, or other prolonged intravenous treatments 2, 5.

Complications and Safety

• Studies have shown that midline catheters have a lower risk of complications, such as catheter-related bloodstream infections and occlusions, compared to PICCs 4.
• However, the risk of deep vein thrombosis (DVT) may be similar or greater with midlines compared to PICCs for short-term use 4.
• Ultrasound-guided placement of midline catheters has been shown to be a cost-effective and safe alternative to PICCs, with a low rate of complications and a high success rate of placement 3, 6.

Comparison of Midline and PICC Lines

• A study comparing midline catheters and PICCs for patients with short-term indications found that midlines were associated with a lower risk of bloodstream infection and occlusion, but a similar risk of DVT 4.
• Another study found that midline catheters had a lower rate of complications per 1000 catheter-days compared to PICCs, with a median time to complication of 8 days 2.