Certified Medical-Surgical Registered Nurse (CMSRN) Practice Exam

The condition that indicates hypoxemia is characterized by low levels of oxygen in the blood. Hypoxemia specifically refers to reduced partial pressure of oxygen (PO2) in arterial blood, which directly affects how efficiently oxygen is being transported from the lungs to the tissues. In contrast, a high saturation of arterial oxygen (SaO2) would indicate that the blood is well-saturated with oxygen, which is not a sign of hypoxemia.

Normal pH levels do not provide explicit information about oxygenation; they primarily reflect the acid-base status of the blood. Meanwhile, while high levels of carbon dioxide (PCO2) can occur in certain respiratory conditions, they do not indicate hypoxemia by themselves and can sometimes be present even when oxygen levels are low. Therefore, low PO2 is clearly the most direct indicator of hypoxemia, making it the correct answer.