John Lee
The Rotherham NHS Foundation Trust, UK

https://doi.org/10.36866/pn.91.50

The range of environments that a basically clothed human can survive in for more than a few hours is remarkably limited. It excludes most of the surface of the earth: the two thirds covered by oceans, the quarter of land which is permanently frozen, the quarter which is arid desert, the lakes and rivers, the high mountains. In fact less than a sixth of the earth’s surface is available to us even with the advantage of having clothes on, and it would be much less than that without our additional technological inventions such as dwellings, fire, weapons and transport to help us get by. The truth is that most of us are completely dependent on technology most of the time. Yet by an almost universal slight of mind we also manage to take all our props for granted to the extent that they become almost invisible, and we perceive ourselves as tough, strong and sturdy masters of the planet, invincible on our upward trajectory.

In fact, upward trajectories are pretty tricky too, and we need aeroplanes, probably our most sophisticated technological inventions in common use, to allow us to survive in what, for us, are the lethally cold and hypoxic conditions that prevail a mere five miles above our heads. Planes which can access this inhospitable environment come in many different shapes and sizes, from the passenger planes with which we are all familiar, to small leisure planes, to high performance military jets, in which high acceleration as they do their stuff adds gravitational forces to the list of dangers. Although a lot of the functions of aeroplanes can be automated, not everything can be, so successful plane flights still require alert humans either at the controls, or standing by at them to take over as and when necessary.

And there lies the focus of this book. How is alertness affected by gravitational forces, or by hypoxia of greater and lesser extent? How does oxygen get into and around the body and what happens when there is less of it? How do we assess alertness, or investigate it if there seems to be a problem? How is it affected by tiredness, the time of day, or by other medical conditions such as hypoglycaemia or headache? What about fainting, or the effects of eye conditions or hearing disorders? And what about pre-existing neurological conditions which may appear quiescent, but which could be disastrous if reactivated in flight? How do we assess the risks?

Anthony Nicholson has brought together a team of 20 experts in neurology, physiology, respiratory medicine and statistics, who provide interesting and thoughtful reviews of these questions in 19 chapters. Clearly the volume will be a must-buy for anyone in the field of aviation medicine. But because hypoxia is an effect of so many common diseases in our ageing population, and because changes in and assessment of alertness are so important in many different situations – from driving or operating machinery, to staff working shifts in prisons or intensive care units – there are many elements of this book which I am sure will find a much wider readership than just the focus audience. And it certainly provides food for thought next time you settle back in your seat, a master of the planet, enveloped in the artificial environment of an aeroplane. Overall an unusual and stimulating volume.

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