Ultrasound-Guided Radial Arterial Line Placement For Critical Care

ultrasound guidance
In the United States, about
8 million catheters are inserted into arteries each year. From this group, a significant number are performed at teaching institutions by residents physicians and at other hospitals usually in the ICU, the OR and occasionally in the ER.

Becoming proficient in placing arterial catheters in critical care settings is essential for healthcare workers who want to improve their first-attempt success rates, reduce complications, and insert catheters more quickly.

Combining the technique with ultrasound guidance improves first-pass success rates compared to mere palpation guidance for radial arterial line placement.

In this article, you can learn more about ultrasound-guided radial arterial line placement in critical care settings. We discuss what it is, when it’s needed, why it’s superior to placements that are exclusively palpation-guided, and its potential complications.

What Is Ultrasound-Guided Radial Arterial Line Placement?

Arterial catheterization is a common procedure in Intensive Care Units (ICUs), operations, and more. Residents and medical professionals in other specialties (such as critical care and emergency medicine) are also expected to be familiar with and skilled in performing the arterial line placement procedure.

The procedure typically involves placing a catheter into the radial artery, which is a major artery in the forearm and runs along its lateral, volar aspect. 

When performed with ultrasound guidance, the procedure involves placing a linear probe on the transverse or longitudinal plane. As the catheter is seen entering the artery, the probe can be set down, and the procedure can be performed in the same way as the usual blind radial arterial line placement.

When Is It Performed?

Radial arterial line placement is essential in several cases, particularly among patients undergoing surgeries and if continuous blood pressure monitoring is needed such as in shock states..

Radial arterial catheter placement is largely helpful in the dynamic, real-time monitoring of blood pressure in patients. This includes patients who are critically ill and experience shock, hypertensive emergencies, and strokes.

It also helps deliver, monitor, and evaluate the effectiveness and outcomes of titratable vasoactive medications.

Radial arterial line placement is also performed when cardiac function must be monitored in conjunction with pulse pressure variance and other technologies.

In addition, the procedure facilitates frequent blood draws in ventilated patients and aids in the overall management of patients requiring critical care.

Why Is Ultrasound Guidance Superior To Palpation-Guided Radial Arterial Line Placement?

Palpation-guided radial arterial line placement, though common, comes with certain limitations as it is particularly difficult to perform among patients with:

  • Severe tachycardia
  • Pitting edema
  • Obesity
  • Hypotension

Owing to the difficulties involved in blind placement, whereby the artery is located and pierced through palpation, several unsuccessful attempts become more likely. This can lead to hematoma, spasms, arterial hemorrhage, or the creation of a false lumen.

A study was conducted to compare the effectiveness and efficiency of residents in a teaching institution performing ultrasound guidance and palpation techniques for arterial line placements. 412 patients and 85 residents in a training program were included in the study and divided into two groups with similar ratios of weight, height, sex, baseline heart rate, baseline systolic blood pressure, and ASA class.

The results showed that the time required to perfect a blind arterial line placement was greater than with ultrasound guidance. Ultrasound-guided radial arterial line placement also required fewer attempts and fewer catheters. It also had a generally higher success rate compared to the blind placement technique.

Overall, ultrasound guidance is the superior technique for radial arterial line placement because:

  • It has a higher first-pass success rate so the risk of complications caused by repeated attempts is reduced, making it safer.
  • It has an overall higher success rate in terms of accuracy, efficiency, and effectiveness.
  • Ultrasound guidance shortens the time needed for catheter placement.
  • The risk of hematomas is drastically reduced with ultrasound-guided arterial line placement procedures.

As a result, ultrasound-guided line placement has become a preferred technique for ensuring safe, effective, accurate, and efficient results whether it be for hemodynamic monitoring, delivering anesthesia, or other medical treatments.

What Are the Potential Complications of Arterial Catheterization?

Radial artery catheterization is the preferred method for monitoring hemodynamics in critically ill patients, delivering anesthesia, and taking blood samples, among other medical activities.

However, the radial arterial line insertion process is associated with some potential complications:

  • Pseudoaneurysm
  • Skin necrosis
  • Median nerve palsy
  • Digital gangrene
  • Thrombosis
  • Cerebral embolization
  • Peripheral neuropathy
  • Radial artery catheter fracture – extremely rare with only one reported case in English language literature 

Other complications typically associated with arterial line insertion, regardless of the insertion site include:

  • Accidental dislodgement
  • Pain and swelling
  • Hemorrhage
  • Limb ischemia
  • Catheter-related infection including bacteremia
  • Iatrogenic blood loss from frequent sampling
  • Heparin-induced thrombocytopenia (if heparin is used in the flush bag)
  • Hematoma 

Despite these potential complications, radial arterial line insertion is a common and necessary practice. With the help of ultrasound guidance, the risk of complications can be mitigated

Final Thoughts

Knowing how to perform a radial arterial line placement is a crucial skill for healthcare professionals, particularly those specializing in anesthesia, critical care, and among first responders.

The procedure is commonly used for anesthesia, monitoring blood pressure, delivering medication, blood collection for tests, and more. It is also used before operations and surgical procedures in some instances.

While there are complications associated with the procedure, ultrasound guidance can ensure that catheters are administered quickly and successfully.

If you would like to learn how to perform ultrasound-guided radial arterial line placement, Hospital Procedures Consultants offers an Arterial Line Course that teaches participants how to insert radial arterial lines, brachial arterial lines, and femoral arterial lines. Our program includes instructions on how to leverage these procedures with the help of ultrasound technology.

To learn more, you can explore our website, call us at 805-339-0225, or email us at [email protected]


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Gibbons, R. Zanaboni, A. Saravitz, S. Costantino, T. Ultrasound Guidance Versus Landmark-Guided Palpation for Radial Arterial Line Placement by Novice Emergency Medicine Interns: A Randomized Controlled Trial. Randomized Controlled Trial J Emerg Med. 2020;59(6):911-917.
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Read all articles in Arterial line, Emergency Procedures, Featured, Ultrasound-Guided Peripheral IV

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