God breathed life into Adam, and that life was sustained by breathing, and goes out when the body dies.

We understand the facts, now.

I’m unsure of how it was historically viewed.

Much of medicinal knowledge, was slowed by religious concepts. Once those constraints, were lifted, we gained exponential understanding of anatomy, and physiology.

Do you think they understood that the exhaled breath could be dangerous if allowed to accumulate? If so, I wonder what they thought was going on?

I worked with animals. We undetrsood, such things. We need a working repertory system, and and pulmonary system. Then, we worked on the other things. It was systematic.
We lost a LOT of patients. But not without effort. Blood glucose, was another game changer. We saved hundreds, and lost hundreds. It affected us all the same…. We cried, when we lost a patient. We celebrated, if we got them back.

I had to put my own dig (my daughter, ) down. I still hate myself, for the act. But she was in endstage renal failure. There was nothing I could do…

If a patient was unable to sustain a certain SPO2, they would suffer consequences, regardless of if we could keep them alive… Permanent brain damage… With CPR, you have a time table. You have to get them back quickly.
Despite best efforts, this doesn’t always occur….

We can keep the physical body alive, but can’t control the oxygen to brain ratios…