Which test must be performed to determine if radial access is feasible?

Which test must be performed to determine if radial access is feasible?

• A. Allen's test
• B. Modified Allen's Test
• C. Oximetric Allen's Test
• D. Doppler ultrasound assessment

Answer: (A)

Assessing whether the hand has adequate collateral circulation before using the radial artery is essential to prevent ischemia if the radial artery is occluded during catheterization. The best bedside test for this is Allen's test. In this test, the patient makes a fist to blanch the hand while both the radial and ulnar arteries are occluded at the wrist. Then the ulnar artery is released while keeping radial occlusion, and you observe how quickly color returns to the hand. If perfusion returns promptly, the ulnar artery and palmar arch can sustain hand blood flow, so radial access is feasible. If color fails to return promptly, relying on the radial artery could jeopardize hand perfusion, so radial access is riskier and alternative access or further evaluation is considered. While there are modified versions and other imaging methods (like Doppler ultrasound) that can provide additional information, the standard test to determine radial access feasibility is the Allen's test.

Assessing whether the hand has adequate collateral circulation before using the radial artery is essential to prevent ischemia if the radial artery is occluded during catheterization. The best bedside test for this is Allen's test. In this test, the patient makes a fist to blanch the hand while both the radial and ulnar arteries are occluded at the wrist. Then the ulnar artery is released while keeping radial occlusion, and you observe how quickly color returns to the hand. If perfusion returns promptly, the ulnar artery and palmar arch can sustain hand blood flow, so radial access is feasible. If color fails to return promptly, relying on the radial artery could jeopardize hand perfusion, so radial access is riskier and alternative access or further evaluation is considered. While there are modified versions and other imaging methods (like Doppler ultrasound) that can provide additional information, the standard test to determine radial access feasibility is the Allen's test.