Tried to find more about when HHP is induced and on risks with oxygen therapy, found this:
https://www.researchgate.net/publication/342456597_The_Hyperoxic-Hypoxic_Paradox
I just speed read the article because I'm tired and having a bad day, and it is simply over my head. Though, I found some good diagrams and this at the end:
4.6. Oxygen Toxicity
Although oxygen therapy is considered to be safe, like other active ingredients or drugs, at high dosage, it can be harmful and result in oxygen toxicity. Prolonged exposure to high oxygen pressure with a prolonged imbalance between ROS to scavengers can lead to membrane lipid peroxidation and enzyme inhibition and modulations, most commonly seen in the central nervous system (CNS),
that lead to alterations in neuronal metabolism and its related electrical activity [120]. As was first suggested in 1878, breathing hyperbaric oxygen can culminate in grand mal seizures [121]. Another organ that is relatively sensitive to oxygen toxicity is the lung. Pulmonary oxygen toxicity can be manifested by chest tightness, cough, and a reversible decline of pulmonary function [122].
Both CNS and pulmonary toxicity depend upon the partial pressure of oxygen and the duration of exposure [123]. Accordingly, the new HBOT protocol used today includes repeated daily sessions limited to 60–90 min with oxygen partial pressure not exceeding 2.4 ATA, as well as air brakes every 20–30 min. Using those new protocols,
HBOT is considered to be safe, while both pulmonary and oxygen toxicity are very rare [124–126]. In a recent analysis of 62,614 hyperbaric sessions, the overall incidence of seizures during hyperbaric sessions was 0.011% (1:8, 945 sessions) [124,125]. In addition, in patients without chronic lung diseases, the currently used HBOT protocols do not cause any pulmonary toxicity or changes in pulmonary functions following 60 repeated exposures.[126].
5. Summary
As in Albert Einstein’s “theory of relativity” that explains the basic physical aspects of our cosmos, relatively can also be found in the micro‐cosmos, i.e., the microenvironmental interpretation at the cellular level. As summarized in Figure 3, most of the cellular cascades initiated by hypoxia can be induced by intermittent hyperoxia, the so‐called “hyperoxic‐hypoxic paradox”. HIF, VEGF, SIRT, mitochondrial biogenesis, and stem cell proliferation and migration could all be induced by “biological fooling” the cells with certain protocols of repeated intermittent hyperoxia.
Even though the exact dose response‐curve has yet to be discovered in clinical practice, certain HBOT protocols have already demonstrated induction of damaged tissue regeneration.