[203] HYPERBARIC CNS OXYGEN TOXICITY - RISK LIMITS DERIVED FROM 15 YEARS OF NBL DIVE OPERATIONS

摘要

INTRODUCTION: CNS 02 tox is a concern with any hyperbaric oxygen exposure. It can result in a variety of clinical symptoms, including seizures. Although rare in hyperbaric oxygen therapy (~1 /10,000 treatments), the risk is higher in dive operations. Furthermore, a seizure during dive operations can have significant repercussions, including death. At NASA's Neutral Buoyancy Laboratory (NBL), astronauts train for EVAs ('spacewalks') underwater. Although neutral buoyancy is effective to mimic microgravity, diving operations carry a risk of decompression illness (DCI) and oxygen toxicity. The risk of DCI is decreased by using a 46% oxygen mixture (Nitrox), but this results in a theoretical increase in risk of oxygen toxicity. NOAA publishes maximum limits for oxygen exposure during diving; however, these were derived from expert opinion and not data. Operational requirements at the NBL results in dives that exceed them.