A 62-year-old truck driver presents to his primary care physician for a preoperative evaluation. He is scheduled to have a coronary artery bypass graft tomorrow. The surgeon would like to harvest a portion of the radial artery to use as one of the bypass grafts. What preliminary test can be performed at the bedside to determine that the patient has adequate hand perfusion from the ulnar artery since the radial artery will be harvested? Trendelenburg test. Palpation of the ulnar artery. Allen test. Tinel’s. Ankle brachial index.