National Physical Therapy Examination (NPTE) Practice Exam

What physiological change is expected in sickle cell anemia when engaging in exercise?

1. Increased blood pressure

2. Improved oxygen delivery

3. Increased risk of hypoxia

4. Enhanced muscle strength

The correct answer is: Increased risk of hypoxia

In sickle cell anemia, engaging in exercise can lead to an increased risk of hypoxia. This is primarily due to the nature of sickle cell disease, where red blood cells can become misshapen and rigid under stress, such as during physical exertion. These deformed cells can clump together and obstruct blood flow, particularly in the small vessels, which may reduce the overall oxygen supply to tissues and organs. As exercise intensifies, increased demand for oxygen occurs, which can trigger a crisis in individuals with sickle cell anemia. This may exacerbate the tendency for the sickled red blood cells to obstruct capillaries, leading to local tissue hypoxia and pain episodes, known as vaso-occlusive crises. Because of these factors, the risk of hypoxia becomes particularly pertinent during physical activity. In contrast, other options do not accurately reflect the physiological responses in individuals with sickle cell anemia during exercise. For instance, blood pressure may not necessarily increase in a way that suggests good health or cardiovascular function, and improved oxygen delivery and enhanced muscle strength are unlikely physiological outcomes given the limitations imposed by the disease. Thus, understanding these dynamics is crucial for assessing individuals with sickle cell anemia during exercise.