Before measuring arterial blood gases (ABGs), what test should be performed?

The performance of Allen's test before measuring arterial blood gases (ABGs) is crucial because it assesses the collateral circulation in the hand. Specifically, it evaluates the adequacy of blood flow through the ulnar artery, which is essential when the radial artery is being used for blood sampling.

If the Allen's test is positive, it indicates that the ulnar artery is providing sufficient blood flow to the hand, minimizing the risk of ischemia to the hand after the blood is drawn from the radial artery. This test is a safety measure to ensure that the patient can tolerate the procedure without experiencing complications related to inadequate blood supply.

In contrast, while other tests such as blood glucose testing or pulse oximetry provide useful health information, they do not directly address the immediate concerns of accessing the arterial blood supply safely for accurate ABG measurement.