Anesthesia Technician Practice Exam

Which condition is characterized by elevated end-tidal carbon dioxide levels?

1. Hypoventilation

2. Hyperventilation

3. Severe dehydration

4. Cardiac arrest

The correct answer is: Hypoventilation

Hypoventilation is characterized by the retention of carbon dioxide due to inadequate ventilation. When a person hypoventilates, the rate and depth of breathing are insufficient to remove CO2 produced from metabolism, leading to an accumulation of carbon dioxide in the bloodstream and subsequently in the exhaled breath. This is reflected in elevated end-tidal carbon dioxide (ETCO2) levels, which can be monitored with capnography during anesthesia or critical care. In contrast, hyperventilation reduces end-tidal carbon dioxide levels as the increased breathing rate leads to excessive elimination of CO2. Severe dehydration does not directly influence ETCO2 but can affect overall physiological function. Cardiac arrest typically results in diminished or absent respiratory function, leading to low or undetectable ETCO2 since there is little to no carbon dioxide being expelled from the lungs. Therefore, hypoventilation is the correct condition associated with elevated end-tidal carbon dioxide levels.