In a premature neonate undergoing emergency repair of a left diaphragmatic hernia, which artery is suitable for preductal arterial blood sampling?

In a premature neonate undergoing emergency repair of a left diaphragmatic hernia, which artery is suitable for preductal arterial blood sampling?

• A. Femoral artery
• B. Umbilical artery
• C. Dorsalis pedis artery
• D. Right radial artery

Answer: (D)

The key idea is preductal arterial blood sampling in neonates. To accurately gauge systemic oxygenation before the ductus arteriosus blends blood from the pulmonary circulation, you want a site that lies upstream of that shunt. The right radial artery feeds the aorta proximal to where the ductus arteriosus inserts, so blood drawn from the right radial artery reflects preductal systemic blood. This makes it the most reliable reflect of cerebral and overall systemic oxygen delivery during emergency neonatal surgery. Sampling from distal arteries such as the femoral or dorsalis pedis would be postductal, meaning the blood has already mixed via the ductus arteriosus and may not represent preductal oxygenation. The umbilical artery, while usable in some NICU contexts, is not the standard preductal site for acute intraoperative monitoring in a premature neonate.

The key idea is preductal arterial blood sampling in neonates. To accurately gauge systemic oxygenation before the ductus arteriosus blends blood from the pulmonary circulation, you want a site that lies upstream of that shunt. The right radial artery feeds the aorta proximal to where the ductus arteriosus inserts, so blood drawn from the right radial artery reflects preductal systemic blood. This makes it the most reliable reflect of cerebral and overall systemic oxygen delivery during emergency neonatal surgery.

Sampling from distal arteries such as the femoral or dorsalis pedis would be postductal, meaning the blood has already mixed via the ductus arteriosus and may not represent preductal oxygenation. The umbilical artery, while usable in some NICU contexts, is not the standard preductal site for acute intraoperative monitoring in a premature neonate.