[abstract] FACE MASK VS. MOUTHPIECE BREATHING - RESPIRATORY FUNCTION AT 6.8 ATA (190 FSW).

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[abstract] FACE MASK VS. MOUTHPIECE BREATHING - RESPIRATORY FUNCTION AT 6.8 ATA (190 FSW).

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Title: [abstract] FACE MASK VS. MOUTHPIECE BREATHING - RESPIRATORY FUNCTION AT 6.8 ATA (190 FSW).
Author: Hickey, DD; Lundgren, CEG; Norfleet, WT
Abstract: The physiological effects of mouthpiece vs. face mask breathing were compared in 4 subjects exposed to varying static lung loads (SLL; +10 to -20 cm H2O) while immersed at 6.8 ATA chamber pressure (190 fsw) and exercising at work loads up to 175 watts. Breathing with a mouthpiece at 190 fsw resulted in substantial reductions (by 21%) in ventilatory volume (VE). In some, but not all, subjects elevations in end-tidal carbon dioxide tension (PetC02) were also observed. Reductions in VE were the result of a lower breathing frequency while using a mouthpiece, whereas tidal volume was maintained. Oxygen consumption, carbon dioxide elimination, and, presumably, carbon dioxide production remained unchanged by mouthpieee or face mask breathing. Since carbon dioxide production and elimination were not affected by the use of a mouthpiece, yet VE was substantially reduced, the absence of elevations in PetC02 in some subjects requires consideration. It is noteworthy that dyspnea was most common while using the mouthpiece. Dyspnea also occurred predominantly at negative static loads. These results are significant in that the occurrence of both hypercapnea and dyspnea threaten the safety of the divert There is a possibility that hypercapnea while breathing from a mouthpiece may be more severe than is indicated by the PetC02 data. The tendency for mouthpiece breathing to cause hypoventilation may possibly call for re-engineering of breathing gear to employ a full face mask design rather than a mouthpiece in certain applications. This work was supported by ONR Contract Number N00014-78-C-0205 with funds provided by the Naval Medical Research and Development Command.
Description: Abstract of the Undersea and Hyperbaric Medical Society, Inc. Annual Scientific Meeting held 11-14 June 1985. The Hyatt Regency Hotel, Long Beach, California (http://www.uhms.org)
URI: http://archive.rubicon-foundation.org/5430
Date: 1985

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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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