Physical Assessment: Allen's Test

Allen's Test is to check for the patency of the radial and ulnar artery. The hand is normally supplied by blood from the ulnar and radial arteries. The arteries undergo anastomosis in the hand. Thus, if the blood supply from one of the arteries is cut off, the other artery can supply adequate blood to the hand. A minority of people lack this dual blood supply. The significance of the test is questioned by medical scientist and recommends a modification of the test since fluorescein dye injections or photoplethysmography are a much reliable test. This test is an preoperative assessment of hand circulation and a routine to test for systemic sclerosis and severe Raynaud's Phenomenon.