American Board of Medicolegal Death Investigators (ABMDI) Practice Exam

What percentage of carbon monoxide in the blood is fatal in healthy adults?

1. 20-30%

2. 40-50%

3. 50-80%

4. 80-90%

The correct answer is: 50-80%

In healthy adults, carbon monoxide levels in the blood can become fatal when they reach a concentration of 50-80%. At this range, carbon monoxide can significantly impair the ability of hemoglobin to carry oxygen, leading to severe hypoxia and potential death if not treated immediately. This critical threshold is important for understanding the toxic effects of carbon monoxide. At lower levels, individuals might experience symptoms such as headaches, dizziness, and confusion, but it is within the 50-80% range that the risk escalates significantly to life-threatening conditions. Higher concentrations, such as those indicated in the higher percentage choices, are extreme and would typically be encountered in cases of severe poisoning in a short time frame, whereas health complications or death can occur at the 50-80% level in a manner that makes it crucial for responders in medicolegal contexts to recognize.