Radiation-Associated Hyperoxic Pulmonary Syndrome
Earth designation: Radiation-Associated Oxygen Toxicity
Radiation-Associated presentation of Oxygen Toxicity in lunar residents. Lung and CNS damage from elevated oxygen partial pressure. Lunar habitats may run on slightly enriched oxygen atmospheres; EVA suits use pure or near-pure oxygen at reduced pressure. Extended pure oxygen breathing can cause pulmonary oxygen toxicity, while high-pressure oxygen causes CNS toxicity.
Lunar Risk Factors
Extended EVA operations in pure oxygen suit atmosphere. Habitat oxygen enrichment above 30% for fire safety reasons. Oxygen concentrator malfunction creating hyperoxygenated zones. Therapeutic oxygen delivery errors.
Symptoms
Pulmonary: chest tightness, cough, dyspnea. CNS: visual disturbances, nausea, twitching, seizures (in hyperbaric conditions).
Lunar Presentation
Pulmonary form most common in lunar context (EVA suit use). Progressive dyspnea after long EVA. CNS form rare except in pressurized habitats with oxygen enrichment.
Diagnosis
Clinical diagnosis based on oxygen exposure history. Chest X-ray shows diffuse infiltrates. PaO2 and SpO2 monitoring.
Treatment
Reduce FiO2 immediately. Supportive care. Corticosteroids may help pulmonary form.
Lunar Medical Bay Protocol
Immediately reduce oxygen to normal habitat air. Remove from enriched oxygen environment. If severe: oxygen titration to SpO2 >92% (not higher). Corticosteroids for pulmonary inflammation. Monitor SpO2 continuously. Earth telemedicine pulmonology consult.
Evacuation Criteria
Severe respiratory failure requiring ventilatory support. Progressive fibrosis. Inability to tolerate any oxygen reduction.
Prevention
Strict oxygen atmosphere protocols. Regular monitoring of habitat O2 levels. EVA time limits in pure O2 suits. Training on oxygen toxicity recognition.