In the Allen test to examine the patency of the radial artery,which of the following indicates normal blood flow?

Question

Quizplus · Accepted Answer

The Allen test is used to examine the patency of the radial and ulnar arteries.This test is usually performed prior to radial artery cannulation because radial artery cannulation is commonly associated with radial artery thrombosis.If the radial artery becomes occluded with a thrombus,continued viability of the hand depends on collateral blood flow from the ulnar artery.If the radial artery is compressed,the blood flow through the ulnar artery should be sufficient to maintain the normal palm color after the patient unclenches the fist.Also,if the ulnar artery is compressed,the blood flow through the radial artery should be sufficient to maintain the normal palm color.This is a positive Allen test.If the color does not return to normal within 6 seconds after the patient unclenches the fist,then obstruction of either the radial or ulnar arteries may be present.This is a negative Allen test.

In the Allen Test to Examine the Patency of the Radial