The sneaky way carbon monoxide poisoning kills. | The Survival Doctorby James Hubbard, MD, MPH

A reader emailed to remind me there’s been a spate of carbon monoxide poisonings and several carbon monoxide deaths to go along with the cold weather in the Northeast United States. To me, that sort of news is always so troubling because even though carbon monoxide is a stealthy killer, the deaths are so preventable. All you need is a working carbon monoxide monitor. (Working is key, so test it occasionally to make sure the audible alarm is good to go. Also ensure the battery is alive and well and you have a few extra batteries just in case.)

No matter how safe your home may seem you need this monitor. Any furnace may malfunction; any vent to the outside may get blocked. All you need is exposure to the fumes of something burning to potentially be in trouble. Whether they’re from automobile exhaust, a generator, or a heater, if you breathe in these odorless fumes, you’re at risk for carbon monoxide poisoning. The only heat that I know of that doesn’t contain carbon monoxide as a byproduct is electric.

For more information about carbon monoxide poisoning from heat sources, check out this post.

How Carbon Monoxide Kills

Inside your lungs are thousands of air sacs that are encased in tiny blood vessels. Oxygen crosses from these sacs over to your blood through the thinnest of membranes. A protein in your red blood cells called hemoglobin attracts the oxygen to it almost like metal to a magnet.

But for some reason, hemoglobin loves carbon monoxide a whole lot more than it does oxygen. In fact, the attraction is over 200 times greater. Since the hemoglobin doesn’t have room for both, the oxygen is left behind. Without oxygen, your cells die.

The brain and heart are affected first, leading to confusion, headaches, etc. With time, this can lead to brain and heart damage and, eventually, death.

If there’s a small concentration of carbon monoxide that takes up only a small portion of the hemoglobin, you might just have the headaches or maybe fatigue. A high concentration is lethal. In general, the higher the concentration, the quicker the death.

But with any concentration, the warning symptoms are often so general that you have no idea you’re being poisoned.

Why You May Not Know You’re Dying

Sometimes with carbon monoxide poisoning, people get short of breath, but not always, and that’s kind of befuddling to me—that we can be deprived of oxygen to the point of death and not have a clue we’re suffocating. But it happens.

In fact, even the scientific methods we have for measuring oxygen levels in the blood can be very misleading. For example: that pulse oximeter that I advise to have in your kit? The one that attaches to your finger to read the oxygen saturation in your blood? Useless for carbon monoxide poisoning. The carbon monoxide fools it into reading normal levels of oxygen when they’re anything but.

Even your body is tricked. Most of the time when a person is low of oxygen, they get a bluish tinge of the skin, especially the lips. But with CO poisoning, the skin can look as nice and pink as normal.

So, the diagnosis comes down to one of suspicion and, if available, a test specifically for carbon monoxide in the blood (not something the average person is likely to have).

Treatment, as I noted in my other post, is to get fresh air or pure oxygen.

Like carbon dioxide, carbon monoxide is eliminated through your lungs when you breathe out. In fresh air, it will take about four hours to get rid of half of the CO concentration in your blood. Breathing pure oxygen reduces the time to about an hour. With hyperbaric oxygen (oxygen delivered in a pressurized way), the time is about 20 minutes. And since the carbon monoxide is suffocating your tissues, time may be of the essence.

What about you? Have you ever experienced the effects of carbon monoxide? Or a scare? Do you have a CO monitor in your home?


Photo: Flickr/rick, “fireplace,” shared under CC BY 2.0.