Medical aspects of compressed air illness / by W.D.M. Paton.

  • William Paton
Date:
[1954?]
Catalogue details

Licence: In copyright

Credit: Medical aspects of compressed air illness / by W.D.M. Paton. Source: Wellcome Collection.

    6/16 page 180
    Variations in susceptibility Variations in susceptibility, due to these and other causes, reveal themselves at a compressed-air working, not so much by the presence there of men with widely differing experience of “ bends ”, but by the elimination of the sus¬ ceptible subjects. One finds, for instance, that among workers who suffered from 44 bends ” once or more in the first 5 days of employment, only 49 per cent are still employed 2 weeks later; whereas of those who did not, 89 per cent are still employed after this time (Paton and Walder, 1954). In con¬ sidering the problems of compressed-air illness in industry, it must be borne in mind that the labour force is highly selected by a strict 44 survival of the fittest ” (“ fitness ” in this case meaning resistance to 44 bends ”). A cclimatization There is also evidence of acclimatization with repeated exposures. It is usually difficult to detect this for certain in the case-histories of single in¬ dividuals; but with a group of men, followed up for several months, it is possible to show that the average incidence falls considerably with prolon¬ gation of experience. Such acclimatization seems to be most rapid during the first 1-2 weeks (Paton and Walder, 1954). These two factors may be the cause of the occasional 44 epidemic ” character of an outbreak of44 bends ” during an undertaking. It is usually associated with an influx of new labour at a point where a new part of the work is being started. The 44 epidemic ” clears up when the susceptible subjects have been eliminated and the others acclimatized. Physiological basis of variations The physiological basis of variation in susceptibility and acclimatization is entirely obscure. There are so many variables in tissue structure and blood flow, in the dynamics of movement, in the response to environmental stimuli, and in individual morale, that it will be long before any clear picture will emerge. SYMPTOMS AND SIGNS OF DECOMPRESSION SICKNESS “ Bends ” Far the commonest important symptom of decompression sickness is a steady aching pain, localized usually to one or more joints of a limb, particularly the knees or shoulders. Wrists, elbows and ankles are also affected, or else the limbs between the joints. Usually the pain is not well localized, but is greatest around the joint, radiating more or less diffusely away from it. Occasionally an intensely painful, single point can be found by palpation in or near an affected joint. Typically in goats, and often in human beings, the pain causes flexion of the joint, apparently in an attempt to ease it; to this may be due the name. The pain varies in intensity from a mild ache (often referred to as the 44 niggles ”) to a pain so severe as to prevent move¬ ment of the limb and to incapacitate the sufferer; it is usually comparable
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