You dirty rat. I can't believe I'm looking at work at home. I don't even like to look at work at work:>) That article hints at what I was saying.
Conclusion
The important clinical fact remains that regardless of the mechanisms involved, oxygen therapy in chronically hypercapnic COPD patients can induce further hypercapnia and acidemia. However, tissue oxygenation is of overriding importance; oxygen must never be withheld from an exacerbated, hypoxemic COPD patient. This means one must be prepared to mechanically support ventilation if necessary.
rtmagazine.com
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CO2 Retention
Q. I was at the emergency room most of the night with my sister, who has severe COPD and will NOT wear her oxygen most of the time. They mentioned that she was a retainer-- I have looked online at this am not able to understand exactly what is happening and what can be done. Any info on CO2 retention will be appreciated. Thanks. Carrie
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A. Folks who have advanced COPD have lungs that have enlarged to the point that when they 'breathe normally' they cannot take in enough fresh air to dilute the CO2-rich air inside their lungs sufficiently to return its concentration back to normal levels. As this condition worsens with the progression of their disease, their CO2 level continues to rise. We call them CO2 retainers because their CO2 levels are higher than normal--sometimes by a large amount.
There are 'some' in the pulmonary medical profession that believe that CO2 retainers get their stimulus to breathe by their oxygen being low. The lower the oxygen level, the stronger the stimulus to breathe. Conversely, the folks are said to "lose" their stimulus to breathe as their oxygen level rises toward and above normal. Therefore, they surmise that it is best to hold back on oxygen for these folks so as to keep them oxygenated just well enough to keep from damaging their heart too much, too soon, BUT not to give them so much as to wipe out their stimulus to breathe.
In the ER the other night, you probably encountered some folks who didn't seem too worried about your sister's poor compliance with wearing/using her oxygen. They weren't concerned because they probably believe that if she WAS using her oxygen more, she might be at risk for increasing her CO2 and diminishing her drive to breathe.
Currently, there is controversy over the validity of this notion/theory. Besides some folks arguing against physiologic theory to support the notion, it is felt that the levels of oxygen which must be maintained are too low AND allow heart damage to occur in an "imposed" fashion. They argue that the oxygen level considered to be adequate for CO2 retainers is significantly lower than the lowest levels they would accept for those who DON'T retain CO2, suggesting that what is good for the goose is NOT also, good for the gander! They argue that persons with CO2 retention levels should use enough oxygen to keep their levels high enough to prevent 'inposition' of damage on the heart and NOT worry about the CO2 retention. They also believe that folks stimulus to breathe won't be adversely affected by having the better oxygen levels.
You would be hard-pressed to find this much discussion about this topic in the popular literature on the internet, let alone elsewhere. AND, until this is settled, it is best to find out what your sister's doctor wants her to do. If he wants her to keep her oxygen on more than she is, then you should encourage her do to so. If he wants her to continue using it only as she feels the need, then, you'll just have to honor that and roll with the resultant punches. Regards, Mark
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