Medicine in extreme environments: danger and opportunity

The problems encountered by expedition doctors are diverse and can be immensely challenging. They range from decompression sickness to high-altitude cerebral oedema, and from immersion hypothermia to the management of multiple trauma patients without any medical kit. Advice was presented on how to deal with these problems and many more. Our understanding of the pathophysiology of high-altitude cerebral oedema is still incomplete, but there is hope that work currently under way may identify genes that predispose individuals to altitude illness. There is active debate among experts about what factors limit exercise performance at high altitude. The accepted explanation has been that a failure of bulk oxygen delivery to the tissues is the limiting factor, but it has been proposed that alternatives such as inefficient microvascular flow or alterations in mitochondrial function may be more important.