Arterial Line Insertion

Your doctor may recommend an arterial line to measure blood pressure continuously. It is especially useful in patients who are critically ill or injured or whose blood pressure is unstable. 

An arterial line also provides a way to take frequent blood samples for lab tests. This avoids repeated needle punctures to draw blood. Lab tests include arterial blood gas testing (ABG). An ABG helps evaluate your oxygen status and acid-base balance. By definition, blood for an ABG comes from an artery.

Your doctor may recommend an arterial line for the following conditions: 

• Cardiovascular conditions including severe uncontrolled hypertension (high blood pressure), heart failure, and cardiopulmonary arrest

• Coma including coma due to stroke and head injury

• Drug overdose or poisoning including ingestion of drugs or exposure to toxins, such as organophosphates including nerve gas

• Low blood pressure (hypotension) including hypotension due to severe bleeding, sepsis, and shock

• Major surgery including open-heart surgery, chest surgery, brain surgery, organ transplants, trauma surgery, and certain abdominal surgeries

• Medications that affect blood pressure including intravenous norepinephrine (Levophed), dopamine, and sodium nitroprusside (Nipride)

• Respiratory failure including respiratory failure due to severe asthma or pulmonary edema

The following doctors insert arterial lines:  

• Cardiologists and cardiac surgeons specialize in diagnosis and treatment of conditions of the heart and its blood vessels. Cardiac surgeons are sometimes called cardiothoracic surgeons.

• Critical care medicine doctors and critical care surgeons specialize in the diagnosis and management of critical and life threatening conditions.

• Emergency medicine doctors and pediatric emergency medicine doctors specialize in rapidly diagnosing and treating acute or sudden illnesses and injuries, and complications of chronic diseases.

• Thoracic surgeons specialize in the surgical treatment of diseases of the chest, including the blood vessels, heart, lungs and esophagus. Thoracic surgeons may also be known as cardiothoracic surgeons.

Other specialists who may insert arterial lines include:

• Registered nurses (RNs) are licensed healthcare professionals who provide skilled patient care and coordinate their care. RNs must have additional training to insert arterial lines.

• Advanced practice nurses (APNs) are registered nurses with advanced specialty training in primary or acute care at the master's level or higher.

Your arterial line insertion will be performed in an intensive care unit (ICU), surgical area, or emergency room setting. The procedure generally includes these steps:

1. You are positioned comfortably so that your doctor or nurse can easily access the insertion area. This is usually the wrist, but may be the inside of the elbow, the groin, a foot, or an armpit.

2. Your doctor or nurse cleans the arterial line insertion area with an antiseptic and numbs the area with a local anesthetic.

3. Your doctor or nurse inserts a small tube (catheter) through the skin into the artery and usually sews it in place.

4. The catheter connects to tubing filled with salt water (saline) and a transducer device. The transducer turns a pressure signal from inside the artery into an electrical signal. The electrical signal appears as a continuous waveform and a blood pressure reading on a monitor screen.

5. Your doctor or nurse covers the arterial line insertion site with a sterile dressing to keep it clean.

Will I feel pain with arterial line insertion?

Your comfort and relaxation is important to you and your care team. You will feel a mild stick and sting when your provider injects the anesthetic. This should pass quickly. You may be aware of having an arterial line, but it should not be painful. 

Tell a member of your care team if you are uncomfortable. You will get pain and sedative medications as needed to keep you comfortable. 

Complications of arterial line insertion are uncommon but can include:

• Allergic reaction to the local anesthetic

• Bleeding

• Blockage of the artery and reduced blood supply to tissues

• Blood clots

• Infection

• Injury to the artery or the extremity that the catheter is in

Reducing your risk of complications

You can reduce the risk of some complications by: 

• Avoiding pulling on the arterial line or scratching at the insertion site

• Ensuring that your care team is aware of your complete medical history. This includes all medications, allergies, and a history of blood clots or a bleeding disorder. Tell your care team about any conditions of your arms or legs, such as having an arteriovenous (AV) graft or fistula for dialysis.

• Following all activity and movement restrictions while the arterial line is in place

• Notifying your doctor or nurse immediately of any concerns. Possible problems include bleeding, pain, swelling, or redness of the arterial line insertion site, or pain, coldness or numbness in the area below the insertion site.

You are an important member of your own healthcare team. You can prepare for your arterial line insertion by answering all questions about your medical history and medications. 

Questions to ask your doctor

You will likely have many questions if you need an arterial line. You or a family member should ask your doctor the following questions:

• Why do I need arterial line? Is blood pressure monitoring with a cuff and routine blood draws an option for me instead of an invasive arterial line?

• How long will I need to have an arterial line?

Arterial lines are generally kept in place for a short period, until you feel better and your condition stabilizes. You will stay in a critical care area where you are closely monitored, usually an intensive care unit (ICU). Your provider may insert a new arterial line if you need it for more than five days.   

A nurse will remove the dressing and pull out the catheter to remove your arterial line. Your nurse will apply firm pressure to the site for about five minutes to prevent bleeding. A new dressing is applied to keep the site clean until it heals.

You should not feel pain during this procedure. Let your nurse know if you are uncomfortable or if you notice any swelling, redness or bleeding from the insertion site.