A woman is claiming that her child’s Easy Bake Oven gave her family carbon monoxide poisoning. This is why people shouldn’t use Google to self diagnose medical problems. The Easy Bake oven uses a lightbulb to generate heat. There is no open flame, thus no combustion. Since carbon monoxide is a product of incomplete combustion, this isn’t the culprit.
The second issue here is that a pulse oximeter allegedly showed 89 percent. This is not caused by CO for technical reasons. See, a pulse oximeter works because hemoglobin that is bound to another molecule absorbs certain frequencies of red light, while hemoglobin that is not bound to another molecule does not. The pulse oximeter shines two frequencies of red light through the body, and measures how much one is absorbed over the other. The result is used to calculate the proportion of bound hemoglobin versus unbound that is passing through the beam.
Carbon monoxide poisoning is caused because CO binds to hemoglobin 200 times more readily than does oxygen. This causes the hemoglobin to form carboxyhemoglobin, which absorbs that red light as readily as oxyhemoglobin, which is formed when oxygen binds to hemoglobin. This means that the pulse oximeter will show the same number whether it is carboxyhemoglobin or oxyhemoglobin. This phenomenon is called the pulse oximetry gap and makes a pulse oximeter useless for diagnosing CO poisoning.
There is a linear decline in O2Hb (oxyhemoglobin) saturation as COHb (carboxyhemoglobin) saturation increases. This decline is not detected by pulse oximetry, which therefore overestimates O2Hb saturation in patients with increased COHb levels. The pulse oximetry gap increases with higher levels of COHb and approximates the COHb level. In patients with possible CO poisoning, pulse oximetry must be considered unreliable and interpreted with caution until the COHb level has been measured. [Bozeman WP, Myers RAM, Barish RA: Confirmation of the pulse oximetry gap in carbon monoxide poisoning. Ann Emerg Med November 1997;30:608-611.]
The fire department found no signs of CO in the apartment, but the couple claims that this was due to the oven having been unplugged 8 hours before.
This entire story is stupidity, and newspapers should be sued for publishing garbage like this with no corroboration other than some moron’s Google search. If you are going to make a claim like this, at least do a little research. Layers of editorial research my hairy ass.
Because I am getting used to providing evidence based resources:
Barker SJ, Tremper KK, The effect of carbon monoxide inhalation on pulse oximetry and transcutaneous PO2. Anesthesiology. 1987; 66: 677-679Gonzalez A
Buckley RG, Aks SE, Eshom JL, et al. The pulse oximetry gap in carbon monoxide intoxication. Ann Emerg Med. 1994; 24: 252-255
Gomez-Arnau J, Pensado A, Carboxyhemoglobin and pulse oximetry.Anesthesiology. 1990; 73: 57