NBRC Normal Values TMC Practice Test

PaO2 is the arterial oxygen tension, showing how well oxygen moves from the lungs into the bloodstream. In a healthy adult at sea level, arterial oxygen tension typically ranges from about 80 to 100 torr. Values within this range indicate adequate oxygen transfer to the blood. When PaO2 falls below this range, it signals varying levels of hypoxemia: around 60–79 torr is mild, about 40–59 torr is moderate, and below 40 torr is severe, though clinical context matters. Values above 100 torr can occur with supplemental oxygen, but the standard baseline normal range remains 80–100 torr.