The student nurse observes the respiratory therapist (RT) preparing to draw an arterial blood gas from the radial artery. The RT performs the Allen's test and the student asks why this test performed before the blood sample is drawn. Which statement made by the RT is most accurate?

Question

The student nurse observes the respiratory therapist (RT) preparing to draw an arterial blood gas from the radial artery.  The RT performs the Allen's test and the student asks why this test performed before the blood sample is drawn.  Which statement made by the RT is most accurate?

Quizplus · Accepted Answer

11ecbb05_cafc_1064_b433_c5ac5cd95a3d_MD0009_00 The radial artery site at the wrist is preferred for collecting an arterial blood gas sample because it is near the surface, is easy to palpate and stabilize, and has good collateral supply from the ulnar artery. The patency of the ulnar artery can be confirmed with a positive modified Allen's test. The modified Allen's test includes the following steps: Instruct the client to make a tight fist (if possible) Occlude the radial and ulnar arteries using firm pressure Instruct the client to open the fist; the palm will be white if both arteries are sufficiently occluded Release the pressure on the ulnar artery; the palm should turn pink within 15 seconds as circulation is restored to the hand, indicating patency of the ulnar artery (positive Allen's test) If the Allen's test is positive, the arterial blood gas can be drawn; if negative and the palm does not return to a pink color, an alternate site (eg, brachial artery, femoral artery) must be used. (Option A) Capillary refill is tested by applying pressure to the fingernail bed to cause blanching. If refill is adequate, the nail bed should become pink in less than 3 seconds after pressure is released. (Option B) The radial artery is palpated with the fingertips to determine the presence of the radial pulse. (Option D) A neurologic deficit is assessed by monitoring color, sensation, and movement of the hand. Educational objective: The radial artery site at the wrist is preferred for collecting an arterial blood gas sample because it is near the surface, easy to palpate and stabilize, and has good collateral supply from the ulnar artery. The patency of the ulnar artery must be confirmed by performing a modified Allen's test to assure adequate circulation to the hand before proceeding with the arterial blood gas collection.

The Student Nurse Observes the Respiratory Therapist (RT) Preparing to Draw