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Effects of underwater breathing apparatus on ventilatory parameters at rest
Author(s) -
Alain Duvallet,
Emilie Duvallet,
Michele Beaudry,
Annick BouchezBuvry
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.1223.1
Subject(s) - tidal volume , ventilation (architecture) , scuba diving , medicine , lung volumes , expiration , anesthesia , positive end expiratory pressure , volume (thermodynamics) , dead space , breathing , airway , elastic recoil , respiratory system , cardiology , lung , mechanical ventilation , meteorology , physics , oceanography , quantum mechanics , geology
The aim of the study was to determine the effect of breathing through a self contained underwater breathing apparatus (SCUBA) on the ventilatory parameters at rest. SCUBA imposed separated inspiratory and expiratory external resistances and increased the dead space. Volumes and maximal flow‐volume loops were randomly performed with and without SCUBA in 160 men and 125 women aged of 30.9 ± 15.1 years. Data were compared by t paired test, ANOVA and ANCOVA. SCUBA did not influence maximal vital capacity (4,15 ± 1,02 vs 4,15 ±1,04 l; p = 0,95), increased the expiratory reserve volume (1,24 ± 0,53 vs 2,36 ± 0,78 l; p<0,0001) and decreased inspiratory capacity (2,91 ± 0,83 vs 2,36 ± 0,78 l; p<0,0001). Scuba decreased significantly all parameters of flow‐volume loops. The results were independent of age, sex, and height. Breathing through a scuba lead to an airway obstruction and shifted the expiratory resting volume in the inspiratory capacity. At high volume, the pulmonary elastic recoil strengths are increased that allowed the expiration easy and inexpensive despite the applied external resistances. Although reduced dynamic lung compliance, the weak external inspiratory resistances and inspired air pressure made the inspiration easy. The available surface area of the valves in the scuba was greater than 50mm2 which was shown to be a threshold to compromise alveolar ventilation (Wasserman, 1995). However, the effect of these modifications on alveolar ventilation and gas exchanges must be study.