Carbon Monoxide Poisoning & CPAP

Within the last day or two, one of the news articles on the streaming news feature of this website was about a man who died of CO poisoning in a hotel while using his CPAP machine. His wife became ill, but it killed him.
http://www.mcall.com/news/local/all-a1_ ... 7820.story

When you think about it it makes sense that if we are breathing air under pressure, a lot more air (and whatever is in it) will pass through our lungs than through the lungs of a non-user.

We are currently having our AC/heat pump replaced which left us without heat last night. Not a problem as we tend to keep the house on the cool side anyway and could use an electric blanket when we went to bed.

We did light a fire in the fireplace during the evening. Extra logs were added to build up a good bed of coals to keep the room warm. After we got into bed, my husband got up and closed the flue so that the cold air wouldn't flood the house when the coals died out while we slept.

A discussion ensued about the dangers of carbon monoxide poisoning. He pointed out that there is a detector at the door of our bedroom, which would protect us. I opened the flue anyway, reasoning that the detector was probably set to a level that would alert a non-user to dangerous levels.

So, what is the level that triggers a CO detector? Would it protect us, or would it sound too late? Is there any way to adjust them to make them more sensitive?

It was cold this morning when we got up, but at least we did wake up, thanks in large part to the timely article posted on this forum.

Susan

Okay, so I just noticed the other thread discussing this topic and basically saying that there is not a greater danger to CPAP users than to the rest of the population.
viewtopic/t27800/Man-dies-in-freak-acci ... -cpap.html

It still seems that the only way air can be delivered under pressure is that more of it is forced through the lungs. The more air, the more whatever is in that air.

On the other hand, Babs is probably right that as an apnea patient it is likely that he suffered other ailments that left him ill equipped to deal with the CO exposure.

Susan

Hi Susan,
We have a fireplace too, and I wouldn't, under ANY circumstances, close a flue until the ashes were comletely cold. Where will all those fumes go?
I'm so glad you decided to open the flue back up.
I'm not trying to make you feel bad. I'm just so glad you opened that flue back up......and don't ever close it again, if there's heat of any kind in the ashes!

Can an oxygen generator used to add oxygen to a cpap machine cause a carbon monoxide detector to go off?

No, only carbon monoxide triggers the alarm.

Perchancetodream wrote: When you think about it it makes sense that if we are breathing air under pressure, a lot more air (and whatever is in it) will pass through our lungs than through the lungs of a non-user.

I would just like to question this statement. If we as CPAP users, had 'a lot more air' passing through our lungs, wouldn't we hyperventilate?
Surely, given similar circumstances, and assuming our body modulates breathing to ensure near to the correct level of oxygenation, we would pass exactly the same amount of air through our lungs as any other person?

CO mixes very freely in the air, so it is unlikely there would be any concentration near the air inlet of the CPAP unit. I would hypothesise that being connected to a CPAP machine would in no way exacerbate the CO poisoning. If someone has any scientific knowledge or thoughts on this, please share.

cands wrote:

Perchancetodream wrote: When you think about it it makes sense that if we are breathing air under pressure, a lot more air (and whatever is in it) will pass through our lungs than through the lungs of a non-user.

I would just like to question this statement. If we as CPAP users, had 'a lot more air' passing through our lungs, wouldn't we hyperventilate?

you're quite right to call bullshit on that "premise"...

cands wrote:

Perchancetodream wrote: When you think about it it makes sense that if we are breathing air under pressure, a lot more air (and whatever is in it) will pass through our lungs than through the lungs of a non-user.

I would just like to question this statement. If we as CPAP users, had 'a lot more air' passing through our lungs, wouldn't we hyperventilate?
Surely, given similar circumstances, and assuming our body modulates breathing to ensure near to the correct level of oxygenation, we would pass exactly the same amount of air through our lungs as any other person?

CO mixes very freely in the air, so it is unlikely there would be any concentration near the air inlet of the CPAP unit. I would hypothesise that being connected to a CPAP machine would in no way exacerbate the CO poisoning. If someone has any scientific knowledge or thoughts on this, please share.

Well, yes and no.

I am not a scientist or an RRT. But I have an opinion.

Pressurizing the airway does not in itself on its own increase the amount of air breathed. However the purpose of pressurizing the airway is to improve how well we breathe when asleep, so it could be argued that breathing well would increase the efficiency of putting whatever is in the air into our bodies. That is not a problem with CPAP; it's the point. We don't avoid good breathing just in case the air gets poisoned.

An aside, but since some of use pulse oximters, if one happens to use a pulse oximiter remember it is not capable of detecting CO - carbon monoxide will register the same as oxygen in the blood in the pulse oximiter reading. In case anyone got the idea to try to rule out CO in their environment or their system becuase their pulse ox is reading normally, that's one mistake that could kill you.

jnk... wrote:

cands wrote:

Perchancetodream wrote: When you think about it it makes sense that if we are breathing air under pressure, a lot more air (and whatever is in it) will pass through our lungs than through the lungs of a non-user.

I would just like to question this statement. If we as CPAP users, had 'a lot more air' passing through our lungs, wouldn't we hyperventilate?
Surely, given similar circumstances, and assuming our body modulates breathing to ensure near to the correct level of oxygenation, we would pass exactly the same amount of air through our lungs as any other person?

CO mixes very freely in the air, so it is unlikely there would be any concentration near the air inlet of the CPAP unit. I would hypothesise that being connected to a CPAP machine would in no way exacerbate the CO poisoning. If someone has any scientific knowledge or thoughts on this, please share.

Well, yes and no.Pressurizing the airway does not in itself on its own increase the amount of air breathed. However the purpose of pressurizing the airway is to improve how well we breathe when asleep, so it could be argued that breathing well would increase the efficiency of putting whatever is in the air into our bodies.

as you say, yes and no.

cpap does increase minute ventilation (the volume of air breathed in and out) above what a person having apnea would experience, but the tiny amount of pressure does not increase minute vent above what a normally breathing person would breath... in addition, the minute vent during sleep is lower than during wake times... I think we did sorta say the same thing, though.

Just a thought towards solving the mystery of why a man using CPAP was fatally exposed, while his wife in the same bed was not. CO is heavier than air, and will settle lower in a quiet room. If his CPAP was located on the floor, that alone would explain his higher exposure and fatal dose.

Sleeprider wrote:Just a thought towards solving the mystery of why a man using CPAP was fatally exposed, while his wife in the same bed was not. CO is heavier than air, and will settle lower in a quiet room. If his CPAP was located on the floor, that alone would explain his higher exposure and fatal dose.

Precisely; if the CO comes into the room via the ductwork, the person sleeping closest to the vent
will be exposed to a greater concentration of gas. The location of the cpap will influence the amount of gas breathed.
This has been demonstrated many times with a non-lethal gas (and a lot of giggles).

What I didn't see anybody suggest in this thread is that the underlying condition (rather than the treatment) could explain what happened. That is the deceased had suffered from Sleep Apnea and might have had problems caused by that rather than the CPAP being responsible.

Sleeprider wrote:Just a thought towards solving the mystery of why a man using CPAP was fatally exposed, while his wife in the same bed was not. CO is heavier than air, and will settle lower in a quiet room. If his CPAP was located on the floor, that alone would explain his higher exposure and fatal dose.

your statement is factually inaccurate.

the specific gravity of carbon monoxide is 0.9667, the specific gravity of atmospheric nitrogen (the major component of air) is 0.9723

so, in a perfectly still room, co would mix.

do try fact checking, please.

different people are, surprise, affected in different amounts by carbon monoxide poisoning, just like everything else. that's why toxicity is stated as a LD50, lethal dose for 50% of the subjects... half die, half live at LD50.