Certified Hyperbaric Technologist Practice Test

What may cause a room air tcOm value to exceed 100 mmHg?

1. High humidity levels

2. Incorrect electrode placement

3. Leakage of atmospheric air

4. Defective electrode

The correct answer is: Leakage of atmospheric air

The room air tcOm value exceeding 100 mmHg is indicative of elevated levels of carbon monoxide in the environment. When atmospheric air leaks into the system being monitored, it introduces normal room air, which contains carbon dioxide and oxygen, but also allows for the possibility of carbon monoxide contamination, especially if there is a source in the environment (e.g., combustion engines, gas appliances). Using this information, leakage of atmospheric air can lead to false readings where the tcOm value may not accurately reflect the true concentration of carbon monoxide present. This is crucial because hyperbaric oxygen therapy makes use of precise gas measurements for safety and effectiveness, and any introduction of room air throws off those readings, leading to potentially harmful misinterpretations of safe levels of carbon monoxide. In contrast, high humidity levels might affect electrode performance but do not directly contribute to a significant increase in the tcOm reading. Incorrect electrode placement may yield inaccurate readings, but it would not systematically elevate the reading beyond a normal range as an air leak could. Additionally, a defective electrode might cause erratic readings rather than a consistent elevation above 100 mmHg. Each of these factors can impact the measurements, but none has the same direct implication as the leakage of atmospheric air.