Certified Hyperbaric Technologist Practice Test

How does Boyle's law affect an ET tube in the hyperbaric chamber?

1. The cuff volume increases during compression

2. The cuff volume remains unchanged during compression

3. The volume of the cuff reduces during compression

4. The cuff is unaffected by pressure changes

The correct answer is: The volume of the cuff reduces during compression

Boyle's law states that at a constant temperature, the volume of a given mass of gas is inversely proportional to the pressure exerted on it. In the context of a hyperbaric chamber, as the pressure inside the chamber increases, the volume of gases, including those within an endotracheal (ET) tube cuff, decreases. When the pressure is applied during compression in the hyperbaric chamber, the gas inside the cuff experiences higher external pressure, causing the gas molecules to compress, which reduces the volume of the cuff. As a result, the cuff becomes smaller as the atmospheric pressure increases, which may potentially affect the effectiveness of the seal created by the cuff around the airway. This understanding aligns with the principles outlined in Boyle's law, confirming that the cuff volume will indeed reduce during compression in a hyperbaric environment. Other options do not accurately represent the relationship described by Boyle's law concerning the behavior of gas volume under pressure.