Why would a patient need an arterial line

Author

Sarah Ogle, DO, MS Fellow in Pediatric Minimally Invasive Bariatric Surgery, Department of Surgery, Children’s Hospital of Colorado, University of Colorado School of Medicine, Anschutz Medical Campus

Sarah Ogle, DO, MS is a member of the following medical societies: American College of Surgeons, Association for Academic Surgery, National Neurotrauma Society

Disclosure: Nothing to disclose.

Coauthor(s)

Ann M Kulungowski, MD Assistant Professor of Pediatric Surgery, University of Colorado School of Medicine

Ann M Kulungowski, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Surgeons, American Pediatric Surgical Association

Disclosure: Nothing to disclose.

Chief Editor

Vincent Lopez Rowe, MD Professor of Surgery, Program Director, Integrated Vascular Surgery Residency and Fellowship, Department of Surgery, Division of Vascular Surgery and Endovascular Therapy, Keck School of Medicine of the University of Southern California

Vincent Lopez Rowe, MD is a member of the following medical societies: American College of Surgeons, American Surgical Association, Pacific Coast Surgical Association, Society for Clinical Vascular Surgery, Society for Vascular Surgery, Western Vascular Society

Disclosure: Nothing to disclose.

Additional Contributors

Taylor L Sawyer, DO, MEd, MBA Professor of Pediatrics, University of Washington School of Medicine

Taylor L Sawyer, DO, MEd, MBA is a member of the following medical societies: Academic Pediatric Association, American Academy of Pediatrics, American College of Osteopathic Pediatricians, American Medical Association, American Osteopathic Association, Association of American Medical Colleges, International Pediatric Simulation Society, Society for Simulation in Healthcare

Disclosure: Nothing to disclose.

Alex Koyfman, MD Assistant Professor, Department of Emergency Medicine, University of Texas Southwestern Medical Center, Parkland Memorial Hospital

Alex Koyfman, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Zachary Radwine, MD Resident Physician, Division of Emergency Medicine, OSF St Francis Medical Center

Zachary Radwine, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Emergency Medicine, American College of Emergency Physicians, Emergency Medicine Residents' Association

Disclosure: Nothing to disclose.

Acknowledgements

Peter D Canning MD, Physician, Department of Emergency Medicine, Rogue Valley Medical Center

Disclosure: Nothing to disclose.

Andrew R Edwards, MD, FACEP Associate Professor of Emergency Medicine, Vice-Chair for Education and Residency Program Director, Department of Emergency Medicine, University of Alabama at Birmingham School of Medicine; Medical Director, Jefferson County SWAT Team, Jefferson County Sheriff's Department

Andrew R Edwards, MD, FACEP is a member of the following medical societies: American College of Physicians, Society for Academic Emergency Medicine, and Wilderness Medical Society

Disclosure: Nothing to disclose.

Christopher J Freeman, MD, FACEP Assistant Professor, Department of Emergency Medicine, University of Alabama at Birmingham School of Medicine; Medical Staff, UAB University Hospital and UAB Highlands Hospital

Christopher J Freeman, MD, FACEP is a member of the following medical societies: American College of Emergency Physicians and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

M Scott Linscott, MD, FACEP Adjunct Professor of Surgery (Clinical), Division of Emergency Medicine, University of Utah School of Medicine

M Scott Linscott, MD, FACEP is a member of the following medical societies: American College of Emergency Physicians, Society for Academic Emergency Medicine, and Utah Medical Association

Disclosure: Nothing to disclose.

Luis M Lovato, MD Associate Clinical Professor, University of California, Los Angeles, David Geffen School of Medicine; Director of Critical Care, Department of Emergency Medicine, Olive View-UCLA Medical Center

Luis M Lovato, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Emergency Physicians, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Robert Ridout, MD Neonatologist, Newborn Medicine Service, Department of Pediatrics, Physician Advisor to Quality Services Division for Process Improvement, Tripler Army Medical Center, Hawaii

Robert Ridout, MD is a member of the following medical societies: American Academy of Pediatrics

Disclosure: Nothing to disclose.

Laurie Scudder, DNP, NP Nurse Planner, Medscape; Clinical Assistant Professor, School of Nursing, George Washington University, Washington, DC

Disclosure: Nothing to disclose.

Gil Z Shlamovitz, MD Assistant Professor, Section of Emergency Medicine, Baylor College of Medicine; Director of Medical Informatics, Emergency Center, Ben Taub General Hospital

Gil Z Shlamovitz, MD is a member of the following medical societies: American Academy of Emergency Medicine and American College of Emergency Physicians

Disclosure: Nothing to disclose.

Timothy G Vedder, MD Neonatology Staff, Tripler Army Medical Center; Assistant Clinical Professor of Pediatrics, University of Hawaii, John A Burns School of Medicine; Associate Professor of Pediatrics, Uniformed Services University of the Health Sciences, F Edward Hebert School of Medicine

Timothy G Vedder, MD is a member of the following medical societies: Society of US Army Flight Surgeons

Disclosure: Nothing to disclose.

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Acknowledgments

The authors wish to thank James Stuart Booth, MD, for his assistance with image capture and processing.

Disclaimer: The views expressed in this manuscript are those of the author(s) and do not reflect the official policy or position of the Department of the Army, the Department of Defense, or the US Government.

Key takeaways:

• An arterial line is a small, flexible tube a healthcare provider places in an artery. They allow care teams to closely monitor someone’s blood pressure. 

• Arterial lines are most common in the intensive care unit (ICU) or during surgery. They help providers know how much medication to give someone. They also allow for frequent blood draws without extra pokes.

• The procedure to insert an arterial line is fast and easy. Complications are rare, but they include bleeding, infection, and blood clots.

An arterial line is a thin, flexible tube a healthcare provider places into one of your arteries. Sometimes people shorten it to “art line.” It calculates your blood pressure every time your heart beats. This means it provides a continuous, more accurate blood pressure than a blood pressure cuff. 

Teams in the intensive care unit (ICU) most often use it when someone is critically ill and needs very close monitoring. It’s also helpful in some surgeries, like ones on the brain or heart. 

If parts of this sound familiar, it may be because arterial lines share some similarities with intravenous (IV) lines. We'll go over what sets them apart and cover when and why healthcare teams use arterial lines.

Why are arterial lines useful? 

Arterial lines are useful in several scenarios:

• Low blood pressure: When someone is very sick or having a big surgery, their blood pressure can get really low. In these cases, they need medications and IV fluids to help increase their blood pressure. An arterial line is useful for knowing how much medication or IV fluids their body needs.

• High blood pressure: Similar to low blood pressure, arterial lines are also helpful when someone’s blood pressure is dangerously high. This way, providers know exactly how much medication they need to lower their blood pressure safely. 

• Critical illness: When someone is in the ICU and on a mechanical ventilator (breathing machine), providers need to closely watch their lungs. They do this by taking frequent blood samples from the artery. They can then measure someone’s oxygen and carbon dioxide levels in the blood.

• Frequent lab testing: There are many medical conditions that need close blood  monitoring. Instead of using a needle to draw new blood every time, an arterial line can draw a blood sample without another poke. 

• Procedures: Cardiologists and radiologists sometimes use arterial lines to perform their procedures, like a heart catheterization.

How do you insert an arterial line?

Providers can insert arterial lines in several different locations. But most often they place them in the radial artery in your wrist. But your provider may also insert one higher up in the arm, in the groin, or even in the foot.

When inserting an arterial line, a provider often uses an ultrasound to help guide them. And this technique is becoming more popular because ultrasounds increase the chance of a successful placement. But providers are also trained to insert them in the right place by feeling for your pulse.

The basic steps to placing an arterial line are similar to those for placing a central line or a big IV: 

• A provider checks multiple locations to find the best spot for the arterial line. They’ll use an ultrasound or feel for a good pulse. 

• They clean the skin over the selected spot with an antibacterial solution. If using the wrist artery, the provider will secure your hand to reduce movement during the procedure.

• They’ll place clean towels or a drape over the area to keep it as clean as possible. 

• The provider will insert a small amount of numbing medication in the area. This makes the rest of the procedure more comfortable. You may feel a brief pinch or sting when they inject the medication under the skin. 

• The provider carefully uses a needle to enter the artery. Once inside the artery, they guide the flexible catheter over the needle into the right place. Then they remove the needle.

• They connect the catheter to tubing and secure it in place. No needles or sharp objects remain after the procedure is complete.

What complications can occur from an arterial line?

Just like any medical procedure, arterial lines have some risks. Fortunately, serious complications occur in less than 5% of cases. They include:

• Pain during placement: A needle is used to get the catheter in the right place, so some pain or discomfort can occur. The numbing medication helps prevent this.

• Bleeding: Since the catheter goes in an artery that carries fast-flowing blood, bleeding can occur during placement and removal of the line. Most of the time the bleeding stops on its own with a little pressure.

• Infections: Any catheter in the body increases the risk of infection of the surrounding skin or the blood. This risk goes up the longer the catheter remains there. Providers use a sterile technique during the procedure to reduce the chance of an infection.

• Blood clots: Sometimes a blood clot forms at the tip of the arterial line catheter. Usually this doesn’t cause significant problems. On very rare occasions, the surrounding skin develops issues from a lack of oxygen (ischemia). But the provider will check blood flow to the area regularly to reduce this risk. 

What is the difference between an arterial line and a central line?

Central lines are big IVs in your neck. There are two main differences between an arterial line and a central IV line:

1. Arterial lines are inserted into an artery — the blood vessels that carry blood away from the heart. Central lines (and all IVs) are inserted into a vein — the blood vessels that carry blood back to the heart. 

2. Central lines and IVs are used to give medications, but arterial lines are not. Healthcare teams use them for monitoring. 

Providers often use these two devices together, especially since the arterial line helps the provider know how much medication to give through the IV. But not everyone needs both. They can be used separately or together.  

Arterial lines are a helpful tool for people who are critically ill or undergoing surgery. Arterial lines monitor your blood pressure with every beat of your heart. And they often save you from having to be poked every time your provider orders lab work. If you have any questions or concerns about arterial lines, be sure to bring them up with your provider before the procedure. That way you’ll understand why you need one and what to expect with the procedure.

GoodRx Health has strict sourcing policies and relies on primary sources such as medical organizations, governmental agencies, academic institutions, and peer-reviewed scientific journals. Learn more about how we ensure our content is accurate, thorough, and unbiased by reading our editorial guidelines.

Boost Heart Health, Not Blood PressureSign up for our Heart Health Newsletter to receive up-to-date information on the latest medications, nutrition tips, and savings that are most relevant to you.

By signing up, I agree to GoodRx's Terms and Privacy Policy, and to receive marketing messages from GoodRx.

By providing your email address, you agree to receive emails containing coupons, refill reminders and promotional messages from GoodRx. You can unsubscribe at any time.

This information is for informational purposes only and is not meant to be a substitute for professional medical advice, diagnosis or treatment. GoodRx is not offering advice, recommending or endorsing any specific prescription drug, pharmacy or other information on the site. GoodRx provides no warranty for any information. Please seek medical advice before starting, changing or terminating any medical treatment.

GoodRx works to make its website accessible to all, including those with disabilities. If you are having difficulty accessing this website, please call or email us at (855) 268-2822 or so that we can provide you with the services you require through alternative means.