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AstoriaDave
Joined: 31 Oct 2005 Posts: 994 City/Region: Astoria
State or Province: OR
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Posted: Wed Nov 25, 2015 11:00 pm Post subject: |
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thataway wrote: | Unfortunately CO poisoning can be very subtle, You can have a large amount in a short time, or a very small amount over a long period. The CO binds the hemoglobin, and those does not allow oxygen to be carried. I have seen a number of cases of CO poisoning where the person had no idea that they had poisoning, until it was too late! | Dr. Bob will have a more accurate account, but I seem to recall that CO binds so tightly to hemoglobin that the Hg has to be broken down to its amino acids, and rebuilt. Hard to avoid breathing while that is going on. _________________ Dave Kruger
Astoria, OR |
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SGIDave
Joined: 16 Jun 2008 Posts: 228 City/Region: St. George Island
State or Province: FL
Vessel Name: Seadation - SOLD 09/2013
Photos: SeaDation
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Posted: Thu Nov 26, 2015 6:50 pm Post subject: |
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AstoriaDave wrote: | thataway wrote: | Unfortunately CO poisoning can be very subtle, You can have a large amount in a short time, or a very small amount over a long period. The CO binds the hemoglobin, and those does not allow oxygen to be carried. I have seen a number of cases of CO poisoning where the person had no idea that they had poisoning, until it was too late! | Dr. Bob will have a more accurate account, but I seem to recall that CO binds so tightly to hemoglobin that the Hg has to be broken down to its amino acids, and rebuilt. Hard to avoid breathing while that is going on. |
CO does not bind irreversibly to the hemoglobin molecule...thus the instructions to get the victim to "fresh" air. EMS first responders and in-hospital treatment will be to provide as near to 100% inhaled O2 until the blood CO level has dropped. CO binds more "tightly" to the O2 receptor but it can (fortunately) be competitively driven off the receptor by providing extra inhaled O2.
CO trivia...smokers commonly have up to 6% CO in their blood when we check blood gas levels in the hospital.
Cyanide is an example of a poison which irreversibly binds to the metabolic equipment within the cell resulting in chemical asphyxiation
dave |
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AstoriaDave
Joined: 31 Oct 2005 Posts: 994 City/Region: Astoria
State or Province: OR
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Posted: Thu Nov 26, 2015 7:03 pm Post subject: |
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Thanks, dave, for correcting my misstatement. Cyanide indeed does bind irreversibly, while CO and O2 bind competitively. CO has some other physiological effects which enhance its adverse action, detailed in this Wikipedia summary, for those interested: https://en.m.wikipedia.org/wiki/Carbon_monoxide_poisoning
No matter how you slice it, CO is a nasty poison. |
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hardee
Joined: 30 Oct 2006 Posts: 12637 City/Region: Sequim
State or Province: WA
C-Dory Year: 2005
C-Dory Model: 22 Cruiser
Vessel Name: Sleepy-C
Photos: SleepyC
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Posted: Thu Nov 26, 2015 7:14 pm Post subject: |
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There are 2 primary treatments for CO poisoning. the first and most accessible is inhaled 100% Oxygen - Oxygen provided through a "high concentration" mask -- one with a soft, flexible bag attached. The second and faster, though not as ever present is a hyperbaric chamber with pressures of 2-3 atmospheric levels.
Carbon monoxide is excreted through the lungs. The half-life in a normal atmosphere is 3 to 4 hours. 100% oxygen reduces this to 30-90 minutes, depending on elevation, and 100% oxygen at hyperbaric pressure of 2.5 atmospheres reduces it to 15-23 minutes. The value of hyperbaric oxygen is, however, unclear but the higher the CO level measured in the patient, the more likely consideration for hyperbaric treatment will be given, assuming there is ready access.
Harvey
SleepyC
 _________________ Though in our sleep we are not conscious of our activity or surroundings, we should not, in our wakefulness, be unconscious of our sleep. |
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thataway
Joined: 02 Nov 2003 Posts: 21387 City/Region: Pensacola
State or Province: FL
C-Dory Year: 2007
C-Dory Model: 25 Cruiser
Vessel Name: thataway
Photos: Thataway
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Posted: Thu Nov 26, 2015 8:30 pm Post subject: |
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Back in the 1970's before there was the crack down on car exhaust omissions, there were studies which showed CO levels approached 25-100 ppm. in drivers of cars on the freeway. I had a number of patients who had vague headaches, myalgia, etc. In taking the history there was a group who either lived right near a freeway or were driving a long time in their cars on the freeways, and had elevated CO levels.
Today the emissions standards have dramatically reduced the CO levels in the exhaust (and less smog).
Although "Diesel is safe"--not necessarily true. There are a number of instances where pure diesel exhaust was piped into an area--including an boat's engine room, and there were very high CO levels.
There are finger nail pulse spread spectrum devices which will non invasively monitor hemoglobin bound CO. This is what the paramedics and Forrest service use for on the spot analysis. It is not as accurate as a blood sample. But in making a decision about treatment the time can be critical.
These are relatively in-expensive in the $800 range, with special transducers for the "Rainbow" spectrum. _________________ Bob Austin
Thataway
Thataway (Ex Seaweed) 2007 25 C Dory May 2018 to Oct. 2021
Thisaway 2006 22' CDory November 2011 to May 2018
Caracal 18 140 Suzuki 2007 to present
Thataway TomCat 255 150 Suzukis June 2006 thru August 2011
C Pelican; 1992, 22 Cruiser, 2002 thru 2006
Frequent Sea; 2003 C D 25, 2007 thru 2009
KA6PKB
Home port: Pensacola FL |
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G.W.
Joined: 09 Sep 2012 Posts: 15 City/Region: Rainy River
State or Province: ON
C-Dory Year: 2012
C-Dory Model: 16 Cruiser
Photos: G.W. (Name TBD)
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Posted: Thu Nov 26, 2015 8:41 pm Post subject: CO detector |
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I found out the hard way to have a CO detector whether you have a heater or not. My 2007 22' had a hard wired detector from the factory. I thought about disconnecting it since I didn't have a heater. First trip out I was cruising slowly with the cabin closed. There was a slight stern wind. I definitely felt tired and drowsy when the alarm went off. To begin with, I thought it was the engine so switched everything off; but still screaming. As soon as I realized the problem and opened the cabin, it shut off. Needless to say, the detector stayed and I always kept a breeze blowing in. It would have been a Bummer to die on your first trip!
G.P. _________________ G.W. |
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