Catheter-Related Thrombosis
A blood clot forming in a vein around an indwelling catheter
Quick Facts
- Type: Vascular condition related to medical devices
- Cause: Clotting around a central line or catheter
- Common sites: Veins in the arm, neck, and chest
- Seek urgent care: Arm or neck swelling, breathlessness, chest pain
Overview
Catheter-related thrombosis is a blood clot that forms in a vein where a central venous catheter or other long-term line is placed. These lines are used to give medicines, fluids, nutrition, chemotherapy, or to perform dialysis, and they are often kept in place for days, weeks, or longer. The presence of the line inside the vein can irritate the vessel wall and slow blood flow, which encourages a clot to form around it.
The clot may stay confined around the catheter, partly or fully block the catheter so it no longer works, or extend along the vein and cause swelling of the limb. In some cases a piece of the clot can break off and travel to the lungs. Recognizing the signs and treating clots promptly helps prevent complications and preserve access for ongoing treatment.
Symptoms
Many small catheter clots cause no symptoms and are found only when the catheter stops working. When symptoms occur, they reflect the vein involved.
- Swelling of the arm, shoulder, neck, or face on the side of the catheter
- Pain, tenderness, or a feeling of fullness along the vein
- Visible, enlarged veins over the chest or arm
- Difficulty flushing the catheter or drawing blood through it
- Redness or warmth over the affected area
If a clot travels to the lungs, it can cause sudden shortness of breath, chest pain, or a fast heartbeat, which is a medical emergency.
Causes
The catheter and the conditions for which it is used both contribute to clotting.
- Vessel irritation: The catheter rubs against and irritates the vein wall, prompting clot formation.
- Slowed blood flow: The catheter takes up space inside the vein and slows blood movement around it.
- Underlying clotting tendency: Many people with catheters have conditions such as cancer or serious illness that themselves raise clot risk.
Larger catheters, more difficult insertions, and lines that stay in place for a long time all add to the chance of a clot.
Risk Factors
- A larger-bore or multiple-lumen catheter
- A line left in place for a long period
- Cancer and chemotherapy
- A previous clot or an inherited clotting disorder
- Difficult or repeated catheter insertion attempts
- The catheter tip positioned away from the ideal spot in the vein
Diagnosis
Diagnosis combines symptoms or catheter problems with imaging.
- Ultrasound: The usual first test for a suspected clot in an arm or neck vein.
- CT or MRI venography: Used for deeper or central veins in the chest that ultrasound cannot see well.
- Catheter function tests: Difficulty flushing or withdrawing blood may prompt checks for a clot blocking the catheter.
Treatment
Treatment depends on the size of the clot, the symptoms, and whether the catheter is still needed.
- Anticoagulants: Blood thinners are the main treatment for a clot in the vein, given for a period of time.
- Keeping or removing the catheter: A working, still-needed catheter is often left in place with anticoagulation; a catheter that is no longer needed or is infected may be removed.
- Clearing a blocked catheter: A clot-dissolving medicine can sometimes be instilled into a catheter that is blocked but otherwise needed.
- Treating complications: A clot that travels to the lungs is treated as a pulmonary embolism.
Prevention
- Using the smallest appropriate catheter size for the needed treatment
- Placing the catheter tip in the recommended position and confirming with imaging
- Removing lines as soon as they are no longer needed
- Careful catheter care and flushing as directed
- Considering preventive measures in people at especially high clot risk
When to See a Doctor
Contact your care team if you have a catheter and notice swelling, pain, or enlarged veins in the arm, neck, or chest, or if the catheter becomes difficult to flush. Seek emergency care immediately for signs of a clot in the lungs:
- Sudden shortness of breath
- Chest pain, especially when breathing in
- A fast or pounding heartbeat
- Fainting or feeling about to faint
These symptoms can be life-threatening and need urgent treatment.
Frequently Asked Questions
What is catheter-related thrombosis?
It is a blood clot that forms in a vein around a central venous catheter or other long-term line. The line can irritate the vein and slow blood flow, encouraging a clot that may block the catheter, swell the limb, or, rarely, travel to the lungs.
What are the signs of a clot around a catheter?
Swelling of the arm, shoulder, neck, or face on the catheter side, pain or fullness along the vein, enlarged surface veins, and difficulty flushing or drawing blood through the catheter are common signs. Many small clots cause no symptoms at all.
Does the catheter have to be removed if a clot forms?
Not always. A catheter that still works and is needed is often kept in place while blood thinners treat the clot. A catheter that is no longer needed, is blocked, or is infected may be removed. The decision depends on the individual situation.
Can a catheter clot be dangerous?
Most are managed successfully, but a clot can block the catheter, cause painful limb swelling, or send a piece to the lungs as a pulmonary embolism, which is an emergency. Seek urgent care for sudden breathlessness or chest pain.
How can catheter-related clots be prevented?
Using the smallest appropriate catheter, positioning the tip correctly, removing lines as soon as they are no longer needed, and careful catheter care all help. People at especially high clot risk may be given additional preventive measures.
References
- MedlinePlus, U.S. National Library of Medicine. Central venous catheter.
- American Society of Hematology. Venous thromboembolism.
- Centers for Disease Control and Prevention (CDC). Venous thromboembolism (blood clots).