Relief of arterial hypoxia and secondary complications. Pulmonary hypertension, polycythemia secondary to hypoxemia, chronic disease states complicated by anemia, cancer, migraine headaches, coronary artery disease, seizure disorders, sickle-cell crisis, and sleep apnea. Hyperbaric oxygen used as antidote for carbon monoxide, carbon tetrachloride, cyanide, hydrocarbon, hydrogen sulfide, methylene chloride, mushroom (Amanita toxin), brown recluse spider bite, chloroform. Decompression sickness, air emboli, and anaerobic infections. Methemoglobinemia. Helium-induced embolism. Ergotamine-induced peripheral ischemia. Necrotic arachnidism caused by Lampona cylindrata (spider found in Australia). Radiation-related bone and soft tissue complications (osteoradionecrosis). Gas gangrene. Administered as supplement with nitrous oxide to ensure adequate ventilation during sedation. Resuscitative agent for medical emergencies in dental office.