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- Dec 15, 2005
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I learned the most amazing thing recently.
The cerebral oximetry monitor rep from Medtronic told one of my partners that prior use of tetracycline makes the monitor read falsely low.
Kids don't get tetracycline because it'll color their developing adult teeth gray. Apparently it colors bone too, and absorbs near infrared light.
She took tetracycline as a teenager for acne. So she puts the monitor on her head and her brain sat reads 20%.
So she told me this and I thought, hey I took tetracycline as a teenager too, let's make this study N=2, and we went into an OR and put it on me
15%
While breathing 15 L/min O2 by mask+reservoir, SpO2 100%:
Still read 15%
Apparently both of our skulls are pigmented enough from tetracycline that near infrared light can't get through. It's been 35ish years since I've taken tetracycline.
And suddenly I have an explanation for why sometimes that monitor just reads 15-20% on some patients no matter what.
I had never heard this about tetracycline and cerebral oximetry before. Even searching the Google afterwards, didn't see anything.
The cerebral oximetry monitor rep from Medtronic told one of my partners that prior use of tetracycline makes the monitor read falsely low.
Kids don't get tetracycline because it'll color their developing adult teeth gray. Apparently it colors bone too, and absorbs near infrared light.
She took tetracycline as a teenager for acne. So she puts the monitor on her head and her brain sat reads 20%.
So she told me this and I thought, hey I took tetracycline as a teenager too, let's make this study N=2, and we went into an OR and put it on me
15%
While breathing 15 L/min O2 by mask+reservoir, SpO2 100%:
Still read 15%
Apparently both of our skulls are pigmented enough from tetracycline that near infrared light can't get through. It's been 35ish years since I've taken tetracycline.
And suddenly I have an explanation for why sometimes that monitor just reads 15-20% on some patients no matter what.
I had never heard this about tetracycline and cerebral oximetry before. Even searching the Google afterwards, didn't see anything.