American Board of Medicolegal Death Investigators (ABMDI) Practice Exam

A blood carbon monoxide level of 40-50% is indeed considered potentially fatal for unhealthy adults. Carbon monoxide (CO) binds to hemoglobin in red blood cells much more efficiently than oxygen does, forming carboxyhemoglobin. When the concentration of carboxyhemoglobin reaches this critical range, it severely impairs the blood's ability to deliver oxygen to vital organs and tissues. At levels of 40-50%, the risk of central nervous system effects increases dramatically, and vital organ dysfunction may lead to death if not addressed particularly quickly. While lower levels can cause symptoms such as headache, dizziness, and confusion, it is in the higher ranges that the situation becomes life-threatening. Understanding these levels is crucial for death investigators and medical professionals, as they can indicate the presence of carbon monoxide poisoning when assessing possible causes of death.