{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T06:50:48Z","timestamp":1782111048025,"version":"3.54.5"},"reference-count":0,"publisher":"Diving and Hyperbaric Medicine Journal","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diving Hyperb Med"],"abstract":"<jats:p>Many competitive breath-hold divers use dry apnoea routines to improve their tolerance to hypoxia and hypercapnia, varying\nthe amount of prior hyperventilation and lung volume. When hyperventilating and exhaling to residual volume prior to\nstarting a breath-hold, hypoxia is reached quickly and without too much discomfort from respiratory drive. Cerebral hypoxia\nwith loss of consciousness (LOC) can easily result. Here, we report on a case where an unsupervised diver used a nose\nclip that is thought to have interfered with his resumption of breathing after LOC. Consequently, he suffered an extended\nperiod of severe hypoxia, with poor ventilation and recovery. He also held his breath on empty lungs; thus, trying to inhale\ncreated an intrathoracic sub-atmospheric pressure. Upon imaging at the hospital, severe intralobular pulmonary oedema was\nnoted, with similarities to images presented in divers suffering from pulmonary barotrauma of descent (squeeze, immersion\npulmonary oedema). Describing the physiological phenomena observed in this case highlights the risks associated with\nunsupervised exhalatory breath-holding after hyperventilation as a training practice in competitive freediving<\/jats:p>","DOI":"10.28920\/dhm51.2.210-215","type":"journal-article","created":{"date-parts":[[2021,6,23]],"date-time":"2021-06-23T19:44:21Z","timestamp":1624477461000},"page":"210-215","source":"Crossref","is-referenced-by-count":5,"title":["Prolonged syncope with multifactorial pulmonary oedema related to dry apnoea training: Safety concerns in unsupervised dry static apnoea"],"prefix":"10.28920","volume":"51","author":[{"given":"Juan M","family":"Valdivia-Valdivia","sequence":"first","affiliation":[{"name":"Neurosurgery Department, St. Joseph\u2019s Hospital, Tampa FL, USA, International Association for Development of Apnea (AIDA International) \u2013 Medical and Science Committee, Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anne","family":"R\u00e4is\u00e4nen-Sokolowski","sequence":"additional","affiliation":[{"name":"Pathology, Helsinki University and Helsinki University Hospital, Helsinki, Finland, The Centre for Military Medicine, The Finnish Defense Forces, Helsinki, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter","family":"Lindholm","sequence":"additional","affiliation":[{"name":"Department of Emergency Medicine, University of California San Diego, San Diego CA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"11463","published-online":{"date-parts":[[2021,6,30]]},"container-title":["Diving and Hyperbaric Medicine Journal"],"original-title":[],"deposited":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T06:40:37Z","timestamp":1782110437000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.dhmjournal.com\/images\/ImmediateRelease\/Valdivia-Valdivia_ProlongedSyncope_2020-116(766).pdf"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,6,30]]},"references-count":0,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2021,6,30]]}},"URL":"https:\/\/doi.org\/10.28920\/dhm51.2.210-215","relation":{},"ISSN":["2209-1491"],"issn-type":[{"value":"2209-1491","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,6,30]]}}}