[abstract] INTERMITTENT PERFUSION AND ALTERNATING BUBBLES IN TENDON.

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[abstract] INTERMITTENT PERFUSION AND ALTERNATING BUBBLES IN TENDON.

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Title: [abstract] INTERMITTENT PERFUSION AND ALTERNATING BUBBLES IN TENDON.
Author: Hills, BA
Abstract: In the formulation of decompression tables, whether from empirical calculation methods or from models, it has been universally assumed that the uptake and elimination of gases are continuous processes unless there has been a sudden change of depth or breathing mixture. There has also been much reluctance to identify "tissues" anatomically, even with single-tissue approaches; although much evidence can be cited to implicate tendon in the aetiology of limb bends. Recent studies of the Achilles tendon in many guinea pigs and bullfrogs have shown that, superimposed upon the normal 'flickering' of capillaries, is a phenomenon whereby whole bundles of capillaries (20-147) open and close with a much lower frequency than the fluctuations in blood flow commonly seen in tissues of high metabolic rate. Unlike skeletal muscle, however, there is little overlap in the tissue zone (1-2 mm) perfused by each bundle and closure times averaged 39 mins in 70 bundles in guinea pigs with some remaining closed for 2 hrs. In decompressed guinea pigs, bubbles were seen to grow until that region was perfused when the local bubbles would rapidly shrink, but start growing again after restitution of perfusion. This suggests that the prevention and treatment of decompression sickness is related to the same phenomenon of alternating bubbles present in tissue almost from the onset of any but a most uneconomical decompression. Alternating bundle patency can explain the delay in the advantages of oxygen breathing and the fact that even the most conservative table occasionally produces a limb bend. The bundle phenomenon can also interpret another anomaly. If diffusion distances of the order of 1-2mm are now used in conjunction with generally accepted values of diffusion coefficients in calculating tissue response times, these are now compatible with diving experience.
URI: http://archive.rubicon-foundation.org/4506
Date: 1979

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  • UHMS Meeting Abstracts
    This is a collection of the published abstracts from the Undersea and Hyperbaric Medical Society (UHMS) annual meetings.

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