What exactly is oxygen toxicity?

Resp arrest.: Pts. With COPD have a problem in letting the co2 out from their lungs. Co2 measurements at the level of the brainstem send a message to the brain and lungs to breath slower or faster. When too much oxygen gets in, the stimulus of co2 stops then the lungs stop moving since there is plenty of oxygen ( respiratory arrest). COPD patients that retain co2 cannot get concent. Of o2 >2 lts. X min.

Part 2: Besides possible respiratory arrest in co2 retainer pts. Also high concentrations of oxygen may cause blindness in small children. Oxygen near a flame or cigarrette may cause and explosion.

Seizures from hyperb: Oxygen toxicity (discovered in the late 1800s & early 1900s) is seizure-like activity or frank seizures that occur from breathing higher-than-usual amounts of oxygen for longer than the toxicity threshhold time. Paul Bert discovered this phenomenon in the context of hyperbaric treatment (administering oxygen at higher than atmospheric pressure) although suspect reports of room pressure tox exist.