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dc.contributor.authorPatrician, Alexander
dc.contributor.authorSprajić, Boris
dc.contributor.authorGasho, Chris
dc.contributor.authorCaldwell, Hannah G.
dc.contributor.authorDawkins, Tony
dc.contributor.authorStembridge, Mike
dc.contributor.authorLovering, Andrew T.
dc.contributor.authorCoombs, Geoff B.
dc.contributor.authorHowe, Connor A.
dc.contributor.authorBarak, Otto
dc.contributor.authorDrvis, Ivan
dc.contributor.authorDujic, Zeljko
dc.contributor.authorAinslie, Philip N.
dc.date.accessioned2021-02-05T10:14:15Z
dc.date.available2021-02-05T10:14:15Z
dc.date.issued2021-02-09
dc.identifier.citationPatrician, A., Spajić, B., Gasho, C., Caldwell, H.G., Dawkins, T., Stembridge, M., Lovering, A.T., Coombs, G.B., Howe, C.A., Barak, O. and Drviš, I. (2021) 'Temporal changes in pulmonary gas exchange efficiency when breath‐hold diving below residual volume', Experimental Physiology. https://doi.org/10.1113/EP089176
dc.identifier.issn0958-0670
dc.identifier.issn1469-445X (electronic)
dc.identifier.urihttp://hdl.handle.net/10369/11291
dc.descriptionArticle published in Experimental Physiology available at https://doi.org/10.1113/EP089176en_US
dc.description.abstractBreath-hold diving involves highly integrative and extreme physiological responses to both exercise and asphyxia during progressive elevations in hydrostatic pressure. Over two diving training camps (Study 1 and 2), 25 breath-hold divers (recreational to world-champion) performed 66 dives to 57{plus minus}20m (range: 18-117m). Using the deepest dive from each diver, temporal changes in cardiopulmonary function were assessed using non-invasive pulmonary gas exchange (indexed via the O2deficit), ultrasound B-line scores, lung compliance, and pulmonary hemodynamics were collected at baseline and following the deepest dive. Hydrostatic-induced lung compression was quantified in Study 2, using spirometry and lung volume measurement, enabling each dive to be categorized by its residual volume (RV)-equivalent depth. From both studies, pulmonary gas exchange inefficiency - defined as an increase in O2 deficit - was related to the depth of the dive (R2=0.345; P<0.001),with dives associated with lung squeeze symptoms exhibiting the greatest deficits. In Study 1, although there was a tendency for B-lines to triple from baseline (p=0.091),cardiac output and pulmonary artery systolic pressure were unchanged post-dive. In Study 2, dives with lung compression to {less than or equal to}RV had higher O2deficits at 9min compared to dives that did not exceed RV (24{plus minus}25mmHg vs.5{plus minus}8mmHg; P=0.021). The physiological significance of a small increase in estimated lung compliance post-dive (via a decrease and increase/unaltered in airway resistance and reactance, respectively) remains equivocal. Following deep dives, the current study highlights an integrated link between hydrostatic-induced lung compression and transient impairments in pulmonary gas exchange efficiency. New Findings: What is the central question of this study? How does deep breath-hold diving impact cardiopulmonary function, both acutely and over the subsequent 2.5 hours post-dive? What is the main finding and its importance? Breath-hold diving to depths below residual volume are associated with acute impairments in pulmonary gas exchange, that typically resolve within 2.5 hours. These data provide new insight into the behavior of the lungs and pulmonary vasculature following deep diving. Dual Publication: Out of the 66 dives included in this manuscript, two dives have been the focus of a case report, which is currently under review (R1) at the Journal of Applied Physiology. The reason for writing up these two dives as a case report, is because they are two of the deepest dives published in the literature, in two of the deepest diving divers in the world. We feel this does not constitute dual publication, since each manuscript are distinctly separate, based on the following main reasons: 1)the purpose of the case report is to purely highlight the uniqueness of each dive in greater detail and include extra measurements/information (e.g. ECG, incidence of nitrogen narcosis), which don't fit into the purpose of this manuscript, which rather focuses on the notion of diving below residual volume and negative impacts to the pulmonary vasculature; 2) Removing these two dives from the current manuscript does not change the statistics or conclusions in the current manuscript in any way, 3) both of these two divers, performed multiple dives during this study, which have all been included in this manuscript, so the diver would be included in the current manuscript regardless. Additionally, for transparency, we have included the following statement in this manuscript (Page 13, line 23): Training status (i.e. phenotypic adaptation) likely plays an influential role - a specific discussion of the deepest divers performing dives beyond 100 m, has been reported elsewhere (Patrician et al., R1 under review).en_US
dc.description.sponsorshipGouvernement du Canada | Natural Sciences and Engineering ResearchCouncil of Canada (Conseil de Recherches en Sciences Naturelles et en Génie duCanada): Alexander Patrician, Hannah G Caldwell, Geoff B Coombs, Connor A Howe,Philip N Ainslie, n/aen_US
dc.language.isoenen_US
dc.publisherWileyen_US
dc.relation.ispartofseriesExperimental Physiology;
dc.titleTemporal changes in pulmonary gas exchange efficiency when breath-hold diving below residual volumeen_US
dc.typeArticleen_US
dc.typeacceptedVersion
dc.identifier.doihttps://doi.org/10.1113/EP089176
dcterms.dateAccepted2021-02-04
rioxxterms.funderCardiff Metropolitan Universityen_US
rioxxterms.identifier.projectCardiff Metropolian (Internal)en_US
rioxxterms.versionAMen_US
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/under-embargo-all-rights-reserveden_US
rioxxterms.freetoread.startdate2022-02-09
rioxxterms.funder.project37baf166-7129-4cd4-b6a1-507454d1372een_US


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