The Sequence of Performing the Allen’s Test for Arterial Blood Sample

QUESTION

The nurse has a prescription to obtain an arterial blood sample from a client. Prior to the procedure the nurse assesses the adequacy of the client’s radial artery by performing the Allen’s test. In which order would the Allen’s test be performed? Place in correct order of priority. All options must be used.

ANSWER

The Sequence of Performing the Allen’s Test for Arterial Blood Sample

Introduction

The Allen’s test is a critical procedure that assesses the adequacy of collateral circulation in the hand before obtaining an arterial blood sample, such as an arterial blood gas (ABG). It ensures that the radial artery is the appropriate site for the procedure and helps prevent complications. In this essay, we will discuss the correct sequence and order of priority for performing the Allen’s test.

Correct Sequence for Performing the Allen’s Test

Explain the Procedure: Before starting, the nurse must first explain the procedure to the client. This is essential to obtain informed consent and to reduce anxiety and discomfort associated with the test. The explanation should include the purpose of the test, its benefits, and any potential risks.

Position the Client: The next step is to position the client appropriately. The client should be seated comfortably, with the forearm supported at heart level. This positioning ensures that gravity does not affect the blood flow during the test.

Locate the Arteries: Once the client is appropriately positioned, the nurse should locate and palpate the radial and ulnar arteries. The radial artery is the focus of the Allen’s test, but it is essential to identify the ulnar artery for comparison.

Apply Pressure to the Ulnar Artery: To perform the Allen’s test, the nurse should apply gentle pressure to the ulnar artery, usually by pressing on it near the client’s wrist. This step temporarily obstructs blood flow through the ulnar artery.

Ask the Client to Make a Fist: While maintaining pressure on the ulnar artery, the client is asked to make a fist with their hand. This action increases the pressure in the hand’s arteries and redirects blood flow to the palm and fingers.

Release Pressure on the Ulnar Artery: After the client has clenched their fist for about 10-15 seconds, the nurse should release pressure on the ulnar artery without releasing the radial artery. The goal is to assess whether blood flow quickly returns to the hand through the ulnar artery.

Observe Return of Color: As the pressure on the ulnar artery is released, the nurse should observe the hand’s color. A prompt return of normal color to the palm and fingers indicates good collateral circulation through the ulnar artery, making the radial artery a suitable site for an arterial blood sample.

Conclusion

The correct sequence for performing the Allen’s test involves explaining the procedure, positioning the client, locating both the radial and ulnar arteries, applying pressure to the ulnar artery, having the client make a fist, releasing pressure on the ulnar artery, and observing the return of normal color to the hand. This systematic approach ensures the adequacy of collateral circulation in the hand, thus ensuring the safety and appropriateness of using the radial artery for obtaining an arterial blood sample.