A Peripherally Inserted Central Catheter (PICC line) is a flexible tube used to deliver medical treatments directly into a large vein near the heart. This intravenous access is intended for therapies lasting several weeks up to several months. A standard PICC line is considered a non-tunneled catheter. The distinction between tunneled and non-tunneled describes how the catheter passes under the skin before entering the bloodstream.
Understanding the PICC Line
A PICC line is a specialized form of central venous access, meaning the tip rests in a large central vein, typically the superior vena cava, located just above the heart. The catheter is inserted into a peripheral vein, usually in the upper arm, which is less invasive than placing other central lines. This placement allows for the safe delivery of medications, such as chemotherapy or total parenteral nutrition, that might otherwise damage smaller peripheral veins.
The PICC line is designed for intermediate durations, making it useful for extended courses of IV antibiotics or long-term fluid management. The line may have one or more openings, called lumens, allowing multiple therapies or fluids to be administered simultaneously. Inserting the line peripherally avoids the need for access in the neck or chest, common sites for other central access devices.
The Difference Between Tunneled and Non-Tunneled Catheters
The classification of a catheter as tunneled or non-tunneled is based purely on the path the tubing takes beneath the skin. A non-tunneled catheter, like a PICC line, enters the vein at or very near the site where it exits the skin. This direct path is structurally simpler and is typically used for shorter periods, though PICC lines are an exception to this duration rule.
In contrast, a tunneled catheter is surgically passed under the skin for a significant distance, creating a subcutaneous tunnel before entering the vein. This tunnel acts as a physical barrier to infection, making the line suitable for long-term use, often six months or more. Many tunneled catheters also feature a Dacron cuff, which tissue grows into, further anchoring the device and providing a second barrier against microbes. A PICC line lacks this subcutaneous tunnel and anchoring cuff, which is the defining structural reason it is categorized as non-tunneled.
Insertion and Routine Care
The non-tunneled nature of the PICC line allows for a less complex and less invasive insertion procedure. The line is often placed at the patient’s bedside or in an outpatient setting using local anesthesia and ultrasound guidance. This contrasts with the minor surgical procedure often required for placing a tunneled catheter.
Routine maintenance focuses heavily on the care of the insertion site, as the direct entry point poses a continuous risk of infection. Care involves regularly changing the sterile dressing and securing the catheter with a specialized device to prevent movement. To keep the lumens open and prevent blood clots, the line must also be flushed with a saline solution, typically at least once a week or after every use. The non-tunneled design also contributes to the relative ease of removal, which is a simple, non-surgical procedure performed by a trained healthcare provider.