Carbon Monoxide Poisoning


A. Usually sewer gas and gas in cellars/basements contains very little CO. The predominant gas in sewers (other than nitrogen as in air everywhere) is either hydrogen sulfide or methane.

B. A "cherry-red" appearance is only seen at dangerously high body carboxyhemoglobin (COHb) concentrations, and on occasion, even not then. It is well-known to be a very poor indicator or CO poisoning.

C. A complete physical exam by a physician is probably the very worst approach. Virtually all of the usual tests given in such exams will not detect CO poisoning. Furthermore, physicians are notoriously bad at diagnosing CO poisoning. In many studies, furnace maintenance and cleaning personnel, chimney sweeps, appliance repair people, etc. are far better at this than physcians.

D. Arterial blood gas measurements need not be done to detect CO in blood. A venous blood sample will suffice. It is less painful and less expensive, and gives the same COHb value. Arterial blood gas is normally not done for a physical exam.

E. Most other blood tests are of no value, expensive, and a waste of time.

F. X-rays generally provide NO USEFUL INFORMATION about CO poisoning.

G. Damage to the lungs by CO poisoning is extremely unlikely and seldom reported, unless the CO level (and COHb level) are very high - at virtually lethal levels. The lungs are virtually transparent to CO movement, and are normally among the best oxygenated tissues of the body.

H. Memory impairment of this sort is the most common cognitive deficit to result from CO poisoning, whether acute or chronic.

I. Steroids are used only in instances of severe, acute CO poisoning. Their use is not a major issue!

J. What the author is talking about here is treatment, again, for instances of severe, acute CO poisoning. The much much more common type of CO poisoning that is not discussed in this article, is chronic, lower level exposure.

K. No mention is made of hyperbaric oxygen (HBO) therapy. Why? This is well-accepted as the best option we have saving lives and for recovery from CO poisoning.

L. Why the mention of STEROIDS again?

M. Ventilators are only used, when necessary, in extremely severe CO poisoning cases.

N. Studies show that the majority of people who suffer severe CO poisoning, no matter how they are treated, incur some residual physical, cognitive, affective, sensory, or gross neurological deficits.

O. Why is there no mention of the need of detailed neuropsychological evaluation by a neuropsychologist expert in CO poisoning? This avenue constitutes a far better set of tools for diagnosis than any physician has available to him/her.

P. Paralysis following even acute, high level CO poisoning is rare. It is not usually the most serious outcome in people with residual neurologic/neuropsychologic deficits.

Q. Regardless of the number of medical reports in the literature about "delayed sequelae" from CO poisoning, it is in my opinion, a rather rare event. Usually the neurologic/neuropsychologic deficit(s) develop almost immediately - there is no delay.

R. Physicians should be far less prone to quickly discharge patients with CO poisoning. CO victims should usually be kept for at least 24 hours after arrival at the ER, and should be given 100% oxygen far longer that what I see has been done in so many medical records I review.

  • I hope this provokes further curiosity about CO poisoning. I welcome comments about my comments, and will honestly attempt to answer all reasonable questions about the subject.

    ...... last changed 09/20/01

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