3 ms·

First, it is not an issue of oxygen intake, more an issue of CO_2 elimination. The fact that non-rigid cloth facemasks at least partially block air exchange is

First, it is not an issue of oxygen intake, more an issue of CO_2 elimination. The fact that non-rigid cloth facemasks at least partially block air exchange is obvious just from how they are inflating during exhalation. Second, i also wondered how healthcare workers could use that for full shifts. Perhaps my experience is related to my health issues (asthma in the past). Or perhaps improvised cloth facemasks are just much worse in this regard than surgical face masks or N95 respirators. Cloth facemasks could have just bigger air 'buffer'. N59 respirators with valve and coth mask on top could be much better, as they would have partially separated in- and out- airflow.

jasonpeacock 6y ago
CO2 elimination is also not an issue: https://twitter.com/MurseWordsworth/status/1276799020673888258 https://twitter.com/MurseWordsworth/status/12767990206738882... And those with chronic health issues also see no problem with masks, despite having existing pulmonary conditions: https://twitter.com/G17Esiason/status/1277249837059264512 https://twitter.com/G17Esiason/status/1277249837059264512 Basically, the volume of air that your lungs can move, in addition to the force of exhaling/inhaling, easily overcomes any air "trapped" in the mask.
- phonypc 6y ago
  Blood oxygen saturation is not informative in this context, and it's disconcerting to see medical professionals treat it like it is. You can hyperventilate until you pass out without your blood oxygen saturation changing.
  - erentz 6y ago
    > Blood oxygen saturation is not informative in this context, and it's disconcerting to see medical professionals treat it like it is. Watch the full video. CO2 is addressed. > You can hyperventilate until you pass out without your blood oxygen saturation changing. Passing out when you hyperventilate is from too little CO2 rather than “retention.“ The opposite of what is being claimed masks cause.
    - phonypc 6y ago
      I did watch the first video in full; the other link, and three others in another post only address blood oxygen. I made no claims about CO2. I don't think wearing a mask will meaningfully affect the breathing of most people, but blood oxygen isn't meaningful in demonstrating as much. Passing out from hyperventilation is a second order effect of hypocapnia; the proximate cause is cerebral hypoxia, despite the blood being saturated.

jasonpeacock 6y ago

CO2 elimination is also not an issue: https://twitter.com/MurseWordsworth/status/1276799020673888258 https://twitter.com/MurseWordsworth/status/12767990206738882... And those with chronic health issues also see no problem with masks, despite having existing pulmonary conditions: https://twitter.com/G17Esiason/status/1277249837059264512 https://twitter.com/G17Esiason/status/1277249837059264512 Basically, the volume of air that your lungs can move, in addition to the force of exhaling/inhaling, easily overcomes any air "trapped" in the mask.

phonypc 6y ago
Blood oxygen saturation is not informative in this context, and it's disconcerting to see medical professionals treat it like it is. You can hyperventilate until you pass out without your blood oxygen saturation changing.
- erentz 6y ago
  > Blood oxygen saturation is not informative in this context, and it's disconcerting to see medical professionals treat it like it is. Watch the full video. CO2 is addressed. > You can hyperventilate until you pass out without your blood oxygen saturation changing. Passing out when you hyperventilate is from too little CO2 rather than “retention.“ The opposite of what is being claimed masks cause.
  - phonypc 6y ago
    I did watch the first video in full; the other link, and three others in another post only address blood oxygen. I made no claims about CO2. I don't think wearing a mask will meaningfully affect the breathing of most people, but blood oxygen isn't meaningful in demonstrating as much. Passing out from hyperventilation is a second order effect of hypocapnia; the proximate cause is cerebral hypoxia, despite the blood being saturated.