Certified Transport Registered Nurse Certification Practice Exam

What type of hypoxia occurs due to tissue oxygen deprivation from poisoning?

1. Hypemic hypoxia

2. Histotoxic hypoxia

3. Stagnant hypoxia

4. Hypoxic hypoxia

The correct answer is: Histotoxic hypoxia

Histotoxic hypoxia occurs when tissues are unable to utilize oxygen effectively, often due to the presence of toxic substances that interfere with cellular metabolism. A common example of this is carbon monoxide poisoning, where carbon monoxide binds to hemoglobin, severely reducing the oxygen-carrying capacity of blood and disrupting cellular respiration. In cases of histotoxic hypoxia, tissue cells are deprived of oxygen because the metabolic pathway is blocked. This type of hypoxia demonstrates how chemical toxins, rather than a lack of oxygen in the environment or issues with blood flow, specifically impair the tissues' ability to use the oxygen available to them. Understanding this concept is crucial for dealing with patients who have been exposed to toxic agents, as their treatment strategies will differ significantly from those for other types of hypoxia.