Cruor (kru-or): The Clotted Portion of Coagulated Blood

While reading through research articles in preparation for a case, I came across a new word. I was quite surprised to find that I had never before encountered this word, considering my particular vocation. Cruor refers to the clotted portion of coagulated blood, according to Merriam-Webster. This is something I encounter at work every single day—and have for almost a decade—yet somehow, I had never come across this word before. The mind boggles.

I had been reading about carbon monoxide poisoning, particularly from vehicle exhaust fumes. While doing so, I was reminded of a story my mother told me many times, in which my entire family very nearly became casualties of this very toxin.

It was an icy winter’s morning in Dalton, in the then-Natal Midlands. The family had lit a fire in a large metal drum for warmth the night before. Later, the drum was brought into the home as everyone readied themselves for bed. They closed up the house but forgot to remove the drum. The ongoing combustion slowly consumed the available oxygen while simultaneously producing carbon monoxide. Ordinarily, this might not have been such a big issue, but the windows and doors had been tightly shut due to the inclement weather.

Silently, the colorless, odorless, and tasteless gas curled its way around the small home. It snuck into every bedroom, finding its way into the noses and lungs of the unsuspecting family as they slept, huddled under their blankets.

One might think that a six-month-old infant would be the first to succumb to this poison. However, in this case, it was the infant who alerted the household to the danger. She awoke and began crying. Though she lay in the same room as her parents, they made no move to respond to her. Her cries grew louder and more intense, eventually waking her aunt in the adjacent room. The aunt tried to reach the child but collapsed in the passage after only a few steps.

The sound of the aunt collapsing, combined with the ongoing cries of the infant, woke the infant’s grandfather. Quickly assessing the situation, he identified the problem and acted immediately, throwing open the doors and windows and removing the drum. By then, everyone in the household was awake and breathing in fresh air, gradually recovering from their exposure to the toxic gas.

Carbon monoxide poisonings have likely been occurring since the dawn of fire itself. Today, we understand how it works. We know the weight of the gas and how it displaces oxygen in the blood, suffocating a person even when there is ample oxygen in their arteries. At autopsy, the telltale bright red blood is a well-known sign of carbon monoxide poisoning. We can test for carboxyhemoglobin, the compound formed during this process, and understand that levels over 40% are usually fatal.

It’s fascinating to wonder what people thought caused such deaths before we had this understanding. Did they attribute it to the work of evil beings? Dark magic? A curse? Or perhaps some misdeed being punished? The more we learn, the more we realize how much there is still to discover.