Peripheral arterial sampling: which site is most commonly used and why?

• A. Radial artery due to easy access and good collateral circulation
• B. Brachial artery because closest to heart
• C. Temporal artery because of ease of palpation
• D. Posterior tibial artery due to large diameter

Answer: (A)

When choosing a site for peripheral arterial sampling, the goal is easy access, a reliable arterial pulse for accurate sampling and monitoring, and minimal risk of complications thanks to safety features of the limb. The radial artery at the wrist best meets these needs in most pediatric patients: it is superficial and usually easy to palpate and cannulate, and the hand has good collateral circulation via the palmar arches (from both radial and ulnar arteries). That collateral network helps maintain hand perfusion if arterial injury or occlusion occurs, making radial sampling safer.

The other sites carry more drawbacks. The brachial artery is deeper and closer to nerves, with higher risk of bleeding, hematoma, and nerve injury and is harder to control in small limbs. The temporal artery often provides unreliable pulsations and is not ideal for accurate sampling in children. The posterior tibial artery is less accessible in neonates and children, with greater risk to the limb and more difficult hemostasis.