from De Telegraaf, 6 April 2020, original in Dutch, accessed 9 April 2020 at

Toxicologist warns COVID-19 patients are dying of carbon monoxide poisoning that pulse oximeters cannot distinguish and both oxygen therapy and ventilators are making worse

Hyattsville, MD: “COVID-19 patients are dying of carbon monoxide poisoning,” warns Albert Donnay, an independent toxicologist and environmental health engineer who has been studying carbon monoxide for 20 years.

Donnay says this poisoning is not from inhaled carbon monoxide (CO) but from endogenous CO that humans make all the time and more so in response to stressors of all kinds. Respiratory infections increase lung CO levels five-fold, from one to five parts per million, which helps kill both bacteria and viruses.

But according to Donnay, days of exposure to higher than normal levels of CO also causes fatigue, cough, shortness of breath, chest pain, headaches, and all the other symptoms of COVID-19. He cautions that when patients are treated with oxygen therapies and mechanical ventilation, they make even more CO in response. They also very effectively flush all this CO out of their lungs into arterial plasma and from there into other organs. As CO gradually accumulates in these tissues beyond the lungs, the hypoxia it causes eventually results in multi-organ failure and death.

Donnay further warns that doctors are missing this CO poisoning because they are not testing for it. The standard pulse oximeters they use in hospitals to monitor oxygen saturation, just like the models used by patients at home, cannot tell the difference between CO and oxygen. The “O2Sat” they display is actually a measure of hemoglobin saturation, which comprises the sum of hemoglobins bound to oxygen, carbon monoxide, and nitric oxide.

Doctors rely on pulse oximeters to see how far oxygen levels are rising or falling. But the actual levels are lower when CO is higher than normal, as it is in people being treated for any condition with oxygen therapy and/or mechanical ventilation.

To stop COVID-19 deaths from CO poisoning, Donnay urges:

1) clinicians and coroners to immediately start testing CO in people with COVID-19. Most hospitals can test for CO non-invasively with a breath analyzer or sensors that measure “SpCO” continuously through a finger-clip or a patch (SpCo is a registered trademark of Masimo Corporation).

Anesthesiologists already use these to monitor CO in operating rooms where the risk of CO poisoning during some kinds of anesthesia has been recognized for decades. Coroners also commonly measure CO but via carboxyhemoglobin (COHb) levels in arterial or venous blood. These are sufficient to identify CO deaths if coroners focus on the difference. In deaths due to other other causes, the arterio-venous COHb gap is less than 2%, but in CO victims it ranges from 4% to over 30%.

2) manufacturers of pulse oximeters and ventilators to issue a global alert warning all their customers of the risks of CO poisoning associated with using their devices as directed. The same warnings need to go on new labels and in new manuals.

3) the US Food and Drug Administration to require Black Box warning labels on these devices alerting users to the risk of fatal CO poisoning associated with their use. To reduce these risk, FDA also should require ventilators to include CO sensors with alarms set at low thresholds.

Donnay’s concerns are based on evidence he has compiled from a review of published studies showing that CO exposure alone may cause all the same signs, symptoms, and complications of COVID-19. He posted a preprint with references that support his hypothesis along with recommendations for testing and treating endogenous CO poisoning to medRxiv on 3/30/2020. This was returned on 4/3/30 as “not research” and so the preprint is now posted at OSF :

[from media release issued by Donnay Detoxicology LLC, 9 April 2020]



consulting toxicologist, environmental health engineer and patented inventor,

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