What indicates a positive modified Allen test result?

A positive modified Allen test result indicates that the collateral circulation in the hand is adequate for performing procedures such as arterial punctures. This test specifically evaluates the patency of the ulnar artery, which is crucial when arterial blood draws are performed from the radial artery.

When the hand color returns to normal within 15 seconds after releasing pressure from the ulnar artery, it demonstrates that the blood flow has been restored effectively. This rapid return of normal color indicates that the ulnar artery is supplying blood adequately to the hand, which is a critical finding before proceeding with venipuncture or arterial blood collection.

Notably, while other options may reflect different health conditions or responses, they do not directly measure the effectiveness of the modified Allen test in assessing arterial supply. For instance, a strong and regular pulse might indicate general circulatory health, but it does not specifically confirm collateral circulation adequacy. Similarly, the absence of pain or a normal capillary refill time, while potentially suggesting good vascular health, do not serve the same diagnostic purpose as the color change observed in the modified Allen test.