Advanced Patient Assessment Practice Exam

In which of the following conditions would secondary polycythemia be least expected?

1. Congenital heart disease

2. Living at high altitude

3. Pulmonary fibrosis

4. Pulmonary embolism

The correct answer is: Pulmonary embolism

Secondary polycythemia is a condition characterized by an increase in red blood cell mass resulting from elevated levels of erythropoietin, often in response to chronic hypoxia or other stimuli. In the context of pulmonary embolism, the acute obstruction of blood flow in the pulmonary arteries leads to decreased oxygenation and can cause hypoxemia; however, this condition is typically abrupt and does not usually provoke the sustained erythropoietin increase associated with chronic hypoxia. Instead, secondary polycythemia develops over time, generally in response to long-term exposure to conditions such as those that induce persistent hypoxia. In contrast, congenital heart disease often leads to altered blood flow patterns, which can ultimately cause chronic hypoxemia and result in secondary polycythemia. Similarly, living at high altitude leads to chronic low oxygen availability, prompting an adaptive increase in red blood cell production. Pulmonary fibrosis, a progressive and chronic respiratory condition, can also result in hypoxia and subsequent polycythemia due to impaired gas exchange. Thus, pulmonary embolism, being an event rather than a sustained state of hypoxia, would least contribute to the development of secondary polycythemia compared to the other listed conditions that induce a chronic hyp