Certified Hyperbaric Technologist Practice Test

What is the half-life of carbon monoxide (CO) when breathing air at sea level?

1. 3 hours, 10 min

2. 5 hours, 20 min

3. 2 hours, 40 min

4. 1 hour, 15 min

The correct answer is: 5 hours, 20 min

The half-life of carbon monoxide (CO) when breathing room air at sea level is approximately 5 hours and 20 minutes. This time reflects the duration it takes for half of the carbon monoxide in the bloodstream to be eliminated when the individual is breathing normal air, which contains low levels of oxygen suitable for this gas exchange. Carbon monoxide binds with hemoglobin, forming carboxyhemoglobin, which reduces the blood's oxygen-carrying capacity. When a person inhales fresh air, the availability of oxygen facilitates the dissociation of carbon monoxide from hemoglobin, thereby allowing the body to metabolize and expel the gas. The specific time for half-life can be influenced by factors such as the initial concentration of carbon monoxide and individual metabolic rates, but under typical conditions at sea level, the estimated half-life is around 5 hours and 20 minutes. Understanding the half-life of carbon monoxide is crucial for hyperbaric technologists, as it helps guide the urgency and duration of treatment in cases of carbon monoxide poisoning, highlighting the importance of providing appropriate therapeutic interventions to expedite the clearance of the toxin from the body.