Journal of the Royal College of Physicians of London
-
J R Coll Physicians Lond · Oct 1993
ReviewDysbarism: the medical problems from high and low atmospheric pressure.
The most serious problems resulting from a change in ambient pressure are pulmonary barotrauma with air embolism and decompression sickness. The small differential pressures used in ventilators at atmospheric pressure may tear lung tissue and, in diving, deaths have occurred from the expansion of pulmonary gas on an ascent of less than two metres. The bubbles of respired gas that enter the systemic circulation often occlude cerebral arteries and may cause infarction. ⋯ If the lung filter is overwhelmed, or microbubbles pass into the systemic arteries through an atrial septal defect, they may open the blood-brain barrier, affecting brain and spinal cord function. Untreated, demyelination with relative preservation of axons may occur, the pathological hallmarks of multiple sclerosis. Gas bubble disease requires urgent compression in a hyperbaric chamber and the use of high partial pressures of oxygen.