= Surgical Masks Increase Pulse, Lower Oxygen Saturation From Rebreathing CO2==
Basically, they looked at doctors performing surgery, and tested their oxygen saturation and pulse rates before and after doing surgery. Since masks are currently required when performing surgery, they used a unmasked control in similar rooms.
The link is to the full text, but basically, oxygen saturation went down about 1%, while pulse increased about 5-10 BPM after surgery.
From the discussion section-
Although decrease in both mental - physical performance and accuracy may sometimes be overcome by the motivation of the surgeon, increased fatigue is common in lengthy operations. The increased endogenous heat production of the surgeon, as well as many aspects of the operating room situation -even the close environment beneath the surgical mask- may also negatively affect the working condition of the surgeon.
Surgical masks may impose some measurable airway resistance, but it seems doubtful if this significantly increases the process of breathing. Although it might have appeared to be likely that hypoxemia results from the increased CO2 content of the inspired air due to the exhaled CO2 getting trapped beneath the surgical face mask; there has been no controlled study concerning with the effect of surgical masks on the level of blood oxygenation.
In this study we have measured the oxygen saturation of arterial pulsations (SpO2 ) by a pulse oximeter and found a statistically significant decrease in the blood O2 saturation level of the surgeons post operationally, which is not due to prolonged standing or stress.
The study paints the increased CO2 as negative, and may be during a task like surgery that is demanding, but I see this as very good news for those of use that want a cheap, easy, and safe way to increase CO2.
Personally, I've worn the mask during the day for about 40 minutes two days now. The first day, I noticed a burst of energy about 10 minutes after removing the mask. Today, my fingers got noticeably warmer when I had the mask on. I also wore it to bed last night. Wasn't that odd, not uncomfortable at all, although didn't notice anything different in the morning.
I find this way easier (and so far, more effective) than bag breathing.
https://raypeatforum.com/community/threads/surgical-masks-increase-pulse-lower-oxygen-saturation-from-rebreathing-co2.18115/
Article on study
Preliminary report on surgical mask induced deoxygenation during major surgery
Outcome …. Considering our findings, this is the first clinical inves- tigation reporting a decrease in blood O2 saturation and an increase in pulse rates of the surgeons after the operations due to surgical mask usage. This change in SpO2 may be either due to the facial mask or the operational stress, since similar changes were observed in the group performing surgery without a mask. However, it cannot be decided whether stress plays any role on the late changes, namely pulse rate increase and SpO2 level decrease; since surgeons are not allowed to perform major surgery without a facial mask in most institutions. In order to better elucidate the effects of stress, a randomized control study should have been conducted in a more controlled environment with different sorts of workers from different gender who are or are not used to wearing face masks on (such as anesthe- siologists, nurses) also working the same durations. Thus, it is important not to generalize the results of this prelimi- nary study, and further studies involving measurement of gas tensions over time, both from blood and from samples obtained under the mask (in order to show a presumed build-up of CO2 under the mask) have to be carried out to elucidate this issue.
FULL study here http://scielo.isciii.es/pdf/neuro/v19n2/3.pdf