Certified Flight Registered Nurse (CFRN) Practice Exam

A patient with a pneumothorax is most susceptible to which type of hypoxia?

1. Stagnant hypoxia

2. Hypoxic hypoxia

3. Histotoxic hypoxia

4. Environmental hypoxia

The correct answer is: Hypoxic hypoxia

The correct answer is hypoxic hypoxia. Understanding the condition of a pneumothorax is key to why this type of hypoxia is relevant. A pneumothorax occurs when air enters the pleural space, leading to a collapse of the affected lung. This injury reduces the lung’s ability to facilitate gas exchange, resulting in decreased oxygen levels in the bloodstream. Hypoxic hypoxia specifically refers to oxygen deficiency in the blood due to an inadequate amount of oxygen being delivered to tissues. In the case of a pneumothorax, the compromised lung function directly impairs the ability to oxygenate blood effectively, making it the most applicable type of hypoxia for this scenario. Oxygen flow into the bloodstream diminishes due to the mechanical disruption of normal respiratory function, exemplifying hypoxic hypoxia. On the contrary, other forms of hypoxia, such as stagnant hypoxia, relate to a decrease in blood flow and are not directly tied to respiratory compromise like a pneumothorax. Histotoxic hypoxia occurs when cells are unable to utilize oxygen efficiently, despite adequate oxygen delivery, often due to toxins. Finally, environmental hypoxia arises from low oxygen availability in the environment, such as high altitudes, rather than an issue with lung functioning.