Certified Hyperbaric Technologist Practice Test

What is the effect of increased pressure during hyperbaric oxygen therapy?

1. Increases gas solubility

2. Decreases tissue perfusion

3. Promotes aerobic metabolism

4. Reduces oxygen toxicity

The correct answer is: Increases gas solubility

In hyperbaric oxygen therapy, increased pressure has a direct effect on gas solubility according to Henry's Law, which states that the amount of gas that dissolves in a liquid is directly proportional to the pressure of the gas above the liquid. Under conditions of higher pressure, the solubility of oxygen in blood and tissues increases significantly. This enhanced solubility allows for a greater quantity of dissolved oxygen to be carried by the plasma, thereby facilitating the transport of oxygen to hypoxic tissues, which is particularly beneficial in various medical conditions treated with hyperbaric therapy. Additionally, while aerobic metabolism is promoted and tissue perfusion can be improved under certain conditions, the key physiological effect of increased pressure is the enhancement of gas solubility. Oxygen toxicity becomes a concern at very high pressures, but moderate hyperbaric conditions usually are designed to mitigate this risk. Therefore, the increase in gas solubility under hyperbaric conditions is the most critical effect aiding in the therapeutic benefits of hyperbaric oxygen therapy.