You’d think we would have given up on common sense by now…

 

Our resident health care professional takes issue with some of the statements made in the video.  As with most things on the internet, the best policy is trust, but verify.  Please take note of Bleatmop’s objections and corrections to what is being put forward as fact:

“At rest your hemoglobin is 99% saturated with oxygen.” False.

At rest, a healthy newborn runs a SPO2 of 99 – 100%. This rapidly declines with age to when you become an adult 92% or above is considered normal. The older you get, the worse your lungs work, to where many elderly naturally SPO2 at 88%. Therefore it is perfectly possible that hyperventilating can increase the oxygen level in your blood.

Furthermore, a SP02 does not equal the partial pressure of oxygen in your blood. While true that SPO2 from 1-99% does usually correlate to a specific PaO2, a SP02 of 100% can mean a PaO2 of 1% more to the amount it takes to create a hyperbaric accident, which is somewhere around double the normal amount of O2 in the blood. Therefore, while you cannot hypersaturate your hemoglobin, you can increase the total amount of O2 in your blood (note, blood does not equal red blood cells), making you be able to hold your breath longer.

What does this mean? Well, hyperventilating can actually increase the total oxygen in your blood beyond that what it takes to saturate your hemoglobin to 100%. The author is right in why hyperventilating causes drowning, as the PaCO2 does mediate your breathing response. However he did not prove that “more oxygen” isn’t why you are able to hold your breath longer. In fact he actually proved that more oxygen (in combination with less carbon dioxide) is why you can actually hold your breath until you pass out

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