What artery does a central line go in? The crucial difference explained

October 2, 2025 •

4 min read

Over 5 million central venous catheters are placed annually in the United States, yet many people wonder, What artery does a central line go in? This is a critical misconception, as central lines are intentionally placed in large veins, not arteries, for important safety and medical reasons.

Quick Summary

A central line is strategically and purposefully inserted into a large vein, such as the internal jugular, subclavian, or femoral, and never into an artery. Accidental arterial placement is a dangerous complication that medical professionals must actively prevent and immediately address to avoid severe patient harm.

Key Points

Veins, not Arteries: A central line is designed for placement in a large vein (central venous catheter), not an artery.
Safety First: Inserting a central line into a high-pressure artery is a serious medical complication, not the intended procedure.
Common Veins: Primary insertion sites include the internal jugular, subclavian, and femoral veins.
Different Catheters for Different Vessels: A different type of catheter, an arterial line, is deliberately placed in an artery for monitoring blood pressure, not for medication.
Ultrasound Guidance: Use of ultrasound is now standard for confirming placement and avoiding the nearby, high-pressure arteries.

Understanding the difference between veins and arteries

For anyone involved in or curious about medical procedures, understanding the fundamental difference between veins and arteries is essential. Arteries carry oxygen-rich blood away from the heart at high pressure, while veins carry deoxygenated blood back to the heart at a much lower pressure. This pressure difference is the key reason why a central venous catheter (CVC), or central line, is placed in a vein. Inserting a catheter into a high-pressure artery would risk severe bleeding, blood clots, and potentially catastrophic complications such as stroke or organ damage.

The proper pathway for a central line

When a central line is inserted, the goal is to access the central venous system, which includes the large veins near the heart. The catheter is carefully threaded through a chosen vein until its tip rests in a large central vessel, such as the superior vena cava or inferior vena cava. This placement near the heart allows for the efficient delivery of medications, large volumes of fluid, and certain types of nutrition that would be too harsh for smaller, peripheral veins.

Common insertion sites for a central line

Medical professionals use specific anatomical locations where large veins are easily accessible and close to the heart. The choice of site depends on the patient's condition, the duration the line is needed, and the specific medical task. The most common sites are:

Internal Jugular (IJ) Vein: Located in the neck, this is a very common site for central line placement. Ultrasound guidance is often used to ensure the needle enters the vein and avoids the nearby carotid artery.
Subclavian Vein: Found under the collarbone (clavicle), this site is associated with lower infection rates but carries a slightly higher risk of mechanical complications, such as a pneumothorax (collapsed lung), compared to the IJ site.
Femoral Vein: Located in the groin, this site is easily accessible during emergencies. However, it is typically associated with a higher risk of infection and blood clots compared to the IJ or subclavian sites.
Peripherally Inserted Central Catheter (PICC) Line: Inserted into a peripheral vein in the upper arm, like the basilic or cephalic vein, the catheter is then threaded toward the heart. PICC lines are suitable for intermediate to long-term venous access.

Accidental arterial cannulation: a serious complication

While careful technique and imaging guidance (like ultrasound) have reduced the risk, accidental placement of a central line into an artery can happen. This is a very serious complication that can have severe consequences, including significant bleeding, hematoma formation, and in some cases, limb ischemia or stroke. When arterial placement is suspected, immediate action is taken, and a vascular surgeon is often consulted. The line is not removed haphazardly, as this could cause major bleeding. Instead, careful surgical planning is needed to manage the situation.

The purpose of an arterial line

For comparison, a different type of catheter, an arterial line, is intentionally placed in an artery, but for a completely different purpose. Arterial lines are used for continuous and accurate blood pressure monitoring and for drawing frequent blood gas samples, not for infusing fluids or medications. They are much smaller and are typically placed in the radial artery in the wrist or the femoral artery in the groin.

Comparing central venous lines and arterial lines

To further clarify the difference, consider the following table comparing central venous catheters and arterial lines.


Feature	Central Venous Catheter	Arterial Line
Target Vessel	Large Vein (e.g., internal jugular, subclavian, femoral)	Artery (e.g., radial, femoral)
Purpose	Administer medication, fluids, nutrition; draw blood; measure central venous pressure	Continuous blood pressure monitoring; frequent blood gas sampling
Blood Pressure	Placed in low-pressure venous system	Placed in high-pressure arterial system
Risk of Complications	Infection, pneumothorax (depending on site), thrombosis	Localized bruising, thrombosis, nerve damage, risk of ischemia
Catheter Size	Typically larger bore to allow for higher flow rates	Smaller bore, designed for monitoring and sampling

Conclusion

To reiterate, a central line is correctly and purposefully placed in a vein, not an artery. This distinction is fundamental to patient safety and the effective delivery of medical care. While complications can occur, modern techniques, including the use of ultrasound, significantly reduce the risk of accidental arterial cannulation. The correct placement of a central line allows for crucial medical treatments that are simply not possible with a standard peripheral IV line. Awareness of the different types of catheters and their intended purpose is a key part of understanding modern hospital care. For more information on patient safety in clinical procedures, you can visit the Agency for Healthcare Research and Quality (AHRQ).

Frequently Asked Questions

Accidental arterial placement is a serious complication that can cause major bleeding, hematoma, nerve damage, or even stroke. If discovered, the catheter is left in place, and a vascular surgeon is immediately notified to manage the removal safely.

Medical professionals use several methods to confirm proper placement. These include using ultrasound visualization during insertion, analyzing blood gas samples from the catheter, and performing a post-procedure chest X-ray to check the catheter's tip position in the chest.

A peripheral IV is a shorter, smaller catheter placed in a small vein, typically in the hand or arm. A central line is a much longer catheter inserted into a large, central vein closer to the heart to deliver stronger medications or fluids that would damage smaller veins.

Central lines are used for several reasons, including administering caustic medications like chemotherapy, providing long-term nutrition (TPN), delivering multiple incompatible medications at once, and for intensive monitoring of critically ill patients.

No, a PICC (Peripherally Inserted Central Catheter) line is a type of central line that is also placed in a vein. It is inserted into a vein in the upper arm, and the catheter is threaded up until its tip is in a large central vein near the heart.

An arterial line is a separate device placed in an artery, like the radial artery in the wrist. It is used exclusively for continuous blood pressure monitoring and blood sampling, and is never used to give medications or fluids.

Yes, aside from a PICC line, other central lines include tunneled catheters (like Hickman or Groshong) which are designed for long-term use and exit the skin away from the insertion site, and implanted ports, which are completely under the skin and accessed with a needle.