Certified Hyperbaric Technologist Practice Test

Which type of gas is primarily expelled from the body during HBOT to treat DCS?

1. Helium

2. Oxygen

3. Nitrogen

4. Carbon dioxide

The correct answer is: Nitrogen

During hyperbaric oxygen therapy (HBOT), the primary focus is on reducing the nitrogen levels in the body to treat decompression sickness (DCS). When divers experience DCS, nitrogen bubbles can form in the bloodstream and tissues due to rapid changes in pressure, as nitrogen is absorbed into the body tissues under higher pressures and released over time as pressure decreases. HBOT involves delivering pure oxygen at higher-than-normal atmospheric pressures, which helps to dissolve more oxygen into the bloodstream and aids in "flushing out" the excess nitrogen. The increased pressure allows nitrogen to be released more efficiently, facilitating its expulsion from the body. This process is crucial for reducing the size of nitrogen bubbles and alleviating the symptoms associated with DCS. Consequently, nitrogen is the gas that is primarily expelled from the body during this therapy, making it the correct answer. In contrast, while oxygen is administered during HBOT, it is not expelled from the body; rather, it is utilized by tissues to promote healing. Carbon dioxide is a waste product that the body expels naturally through respiration and is not specifically targeted during HBOT for DCS treatment. Helium can be used in specific diving situations but does not play a primary role in the standard treatment for D