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Placement of an Arterial Line
Ken Tegtmeyer, M.D., Glenn Brady, M.D., Susanna Lai, M.P.H., Richard Hodo, and Dana Braner, M.D.
Indications

Radial arterial lines are important tools in the treatment of critically ill patients. Continuous monitoring of blood pressure is indicated for patients withhemodynamic instability that requires inotropic or vasopressor medication. An arterial line allows for consistent and continuous monitoring of blood pressure to facilitate the reliable titration of supportive medications. In addition, arterial lines allow for reliable access to the arterial circulation for the measurement of arterial oxygenation and for frequent blood sampling. The placement ofarterial lines is an important skill for physicians to master as they treat critically ill patients. An arterial line is also indicated for patients with significant ventilatory deficits. Measurement of the partial pressures of arterial oxygen and arterial carbon dioxide provides more information about the status of gas exchange than does arterial oxygen saturation.
Contraindications

From theDepartments of Medical Informatics and Clinical Epidemiology and Pediatrics, Oregon Health and Sciences University, Portland, Oreg. Address reprint requests to Dr. Braner at 3181 S.W. Sam Jackson Park Rd., Portland, OR 97239-3098, or at branerd@ohsu.edu. N Engl J Med 2006;354:e13.
Copyright © 2006 Massachusetts Medical Society.

The contraindications to the placement of an arterial line are fewbut specific. Placement of an arterial line should not compromise the circulation distal to the placement site, which means that sites with known deficiencies in collateral circulation — such as those involved in Raynaud’s phenomenon and thromboangiitis obliterans or end arteries such as the brachial artery — should be avoided. The value of the Allen test, which is used to verify collateralcirculation to the Location of the radial artery. hand through alternate occlusion of the radial and ulnar arteries while the hand is checked for perfusion, is somewhat controversial. Some studies have been able to demonstrate adequate perfusion with the use of other techniques that contradict the results of the Allen test.1,2 Other contraindications include infection of the site where the catheter is tobe placed and traumatic injury proximal to the proposed insertion site.
Preparation

There are several techniques for the placement of a radial arterial line; two of the more common are known as “over the wire” and “over the needle.” A modified Performance of the Allen test. Seldinger technique can also be used but is not described in this video. Preparation for both techniques is identical.The equipment needed includes a sterile preparation solution and a sterile field, a board and tape to secure and position the wrist, 1 percent lidocaine solution (without epinephrine) and a smallgauge needle and syringe for delivery, an angiographic catheter and needle, a wire if the over-the-wire technique is to be used, material such as suture or tape to secure the line once it has been placed,and a transduction system for monitoring. After the risks of the procedure have been appropriately assessed and consent has been obtained from the patient, the hand should be positioned on the wrist board. The hand should be placed in moderate dorsiflexion, which brings the artery

n engl j med 354;15

www.nejm.org

april 13, 2006

e13

Downloaded from www.nejm.org on August 18, 2006 .Copyright © 2006 Massachusetts Medical Society. All rights reserved.

placement of an arterial line

closer to the skin and aids successful placement of the line. A flexible board or roll placed under the wrist can ease positioning. The site should be cleaned with a sterile preparation solution and draped appropriately. Sterile gloves should be used for catheter placement.
Placement of the...