ABSTRACT
Decompression illness results from acute exposure to reduced ambient pressure. Wide range of clinical presentation including musculoskeletal, cutaneous, pulmonary, neurological. Symptoms thought to be caused by bubble formation in circulation and tissues. Treatment includes 100% oxygen and re-pressurisation/hyperbaric oxygen therapy. Sub-atmospheric decompression illness (DCI) results from hypobaric decompression to ambient pressures less than 1 atm. May occur during ascent to altitude in aircraft, use of extra-vehicular activity spacesuit, or decompression in hypobaric chamber. Sub-atmospheric DCI includes: Decompression sickness and Arterial gas embolism. Preoxygenation time to reduce risk during exposure to 25,000 ft for 20–30 minutes is typically around 30 minutes; longer preoxygenation times for higher altitudes or more hazardous activities. In general population white matter hyperintensities (WMH) associated with clinical conditions, including cardiovascular disease and symptomatic cerebrovascular disease. Causality, prevalence, exposure threshold and significance of WMH under investigation.
