In adults, which arterial site is most commonly used for arterial blood gas collection when a palpable artery is available?

• A. Brachial artery
• B. Radial artery
• C. Femoral artery
• D. Ulnar artery

Answer: (B)

Choosing a safe, accessible artery for arterial blood gas collection when a palpable artery is available. The radial artery is the usual choice in adults because it sits close to the skin, is easy to palpate, and puncture tends to be straightforward with minimal discomfort and complications. A key safety step is confirming adequate hand circulation with the Allen test before using the radial site, since the hand relies on collateral flow from the ulnar artery if the radial artery cannot be used. While other sites like the brachial, femoral, or ulnar arteries can be used in certain situations, they carry higher risks or are harder to access, making them less preferred when a palpable radial artery is present.