A nurse assisting with data collection of the peripheral vascular system performs the Allen test. The nurse understands that this test is used to determine the patency of which blood vessel(s)?

The nurse performs the Allen test to determine the patency of the radial and ulnar arteries. During the test, the nurse applies pressure over the client's ulnar and radial arteries simultaneously. The client is then asked to open and close the hand repeatedly, causing the hand to blanch. Subsequently, the nurse releases pressure from the ulnar artery while compressing the radial artery and checks the color of the extremity distal to the pressure point. If pinkness fails to return within 6 seconds, it indicates that the ulnar artery is insufficient, suggesting that the radial artery should not be used for obtaining a blood specimen. Choice A (Capillaries) is incorrect as the Allen test assesses the patency of larger arteries, not capillaries. Choice B (Pedal pulses) is incorrect as the Allen test specifically evaluates the radial and ulnar arteries, not the pedal pulses in the foot. Choice C (Femoral arteries) is incorrect as the Allen test focuses on the radial and ulnar arteries in the hand, not the femoral arteries in the leg.