Understanding Carboxyhemoglobin in Niles Hotel Poisoning

Carboxyhemoglobin in Niles Hotel Poisoning?

What do references to Carboxyhemoglobin in Niles Hotel mean? Carboxyhemoglobin is the term to refer to the amount of carbon monoxide in the blood, the hemoglobin. Generally, the amount of carboxyhemoglobin is directly related to the amount of carbon monoxide in the ambient air (indoor air) and the length of time a person breaths that poisoned air. Statements from the Niles Fire Department indicate that readings were as high as 800 ppm when they arrived on the scene in the pool area.

800 ppm is a deadly level. Alarms should go off in a relatively short period of time when levels exceed 100 ppm. The ASHRAE sets maximum exposure at 9 ppm in an 8 hour day. Yet, 800 ppm is not high enough to cause rapid unconsciousness. See http://www.detectcarbonmonoxide.com/co-health-risks/ It likely took more than an hour for that to happen in the Niles, Michigan Quality Inn and Suites pool area. Thus, a working alarm there would have made an immense difference.

Carboxyhemoglobin levels go up as the carbon monoxide ppm goes up and the exposure extends over time. Most alarms are guaranteed to go off before the carboxyhemoglobin level gets to 10%. But that is way too late to prevent all health risks. Levels up to 10 create a risk of symptoms and permanent brain damage. Scientific research indicates that when carboxyhemoglobin levels peak above 10% that there is a significant risk of permanent brain damage.  See Chambers CA¹, Hopkins RO, Weaver LK, Key C, Cognitive and affective outcomes of more severe compared to less severe carbon monoxide poisoning, published in Brain Inj. 2008 May;22(5):387-95. doi: 10.1080/02699050802008075. https://www.ncbi.nlm.nih.gov/pubmed/18415719

The carboxyhemoglobin in Niles Hotel poisoning were likely closer to 50 than to 10. At that levels, hyperbaric oxygen therapy is mandated. From news reports, it would appear that most of those overcome are likely getting hyperbaric oxygen therapy. To not do so would be horribly misguided. According to the New England Journal of Medicine, http://www.nejm.org/doi/full/10.1056/NEJMoa013121#t=article  hyperbaric oxygen helps to increase oxygen in the blood and accelerates the elimination fo carbon monoxide from hemoglobin. It is also believed to help prevent lip peroxidation in the brain and the preserve ATP levels in tissue. While we don’t entirely understand why the effects of carbon monoxide continue to get worse, even when normal oxygen levels are restored, there should be no controversy that hyperbaric oxygen therapy substantially reduces the risk factors for those events.

The last 48 hours have undoubtedly been awful for all those impacted by the Niles, Michigan Quality Inn and Suites poisoning. Unfortunately, hospital discharge may not be the end of the crisis. Carbon monoxide poisoning is known to cause serious delayed symptoms, symptoms which are often worse than those associated with the initial event. While the levels in the Niles, Michigan Quality Inn and Suites pool area were so severe that asphixiation occurred, that lack of oxygen event is only half of the poisoning equation with carboxyhemoglobin.

The body responds to carboxyhemoglobin as a toxin, setting off a radical defense response that continues for days and weeks after the hypoxia (lack of oxygen) event has passed. That secondary immunological response can continue to make survivors sick for weeks. Those who have the secondary sickness are at much higher risk of permanent brain damage.