Certified Transport Registered Nurse Certification Practice Exam

Which scenario illustrates an example of stagnant hypoxia?

1. Severe blood loss from an injury

2. Carbon monoxide exposure

3. Use of tourniquets

4. Living at high altitudes

The correct answer is: Use of tourniquets

Stagnant hypoxia refers to a decreased oxygen availability to the tissues caused by inadequate blood flow, rather than a deficiency in the actual oxygen content in the blood itself. Using tourniquets can significantly restrict blood flow to a limb, leading to a situation where the affected tissue does not receive enough oxygen-rich blood, thereby resulting in stagnant hypoxia in that area. In this scenario, the tourniquet creates a physical barrier to circulation, causing hypoxia as the ongoing metabolic demands of the tissue cannot be met. As a result, even if the overall oxygen levels in the body are normal, tissues beyond the tourniquet will not receive the oxygen they require, illustrating the core concept of stagnant hypoxia. The other options depict different types of hypoxia or conditions that do not fit the definition of stagnant hypoxia. For instance, severe blood loss from an injury would indicate a general decrease in total blood volume leading to a different form of hypoxia, whereas carbon monoxide exposure causes hypoxia through impaired oxygen delivery at the cellular level, and living at high altitudes relates to hypoxia induced by a low partial pressure of oxygen in the environment rather than a flow issue.