Regulation of Brain Blood Flow and Oxygen Delivery in Elite Breath-Hold Divers (CROSBI ID 208432)
Prilog u časopisu | izvorni znanstveni rad | međunarodna recenzija
Podaci o odgovornosti
Willie, CK ; Ainslie, PN ; Drviš, Ivan ; MacLeod, DB ; Bain, AR ; Madden, Dennis ; Zubin Maslov, Petra ; Dujić, Željko ;
engleski
Regulation of Brain Blood Flow and Oxygen Delivery in Elite Breath-Hold Divers
The roles of involuntary breathing movements (IBM) and cerebral oxygen delivery in the tolerance to extreme hypoxaemia displayed by elite breath-hold divers is unknown. Cerebral blood flow (CBF), arterial blood gases (ABG) and cardiorespiratory metrics were measured during maximum dry apneas in elite breath-hold divers (n=17). To isolate the effects of apnea and IBM from the concurrent changes to ABG, end-tidal forcing (“clamp”) was then used to replicate an identical temporal pattern of decreasing arterial PO2 (PaO2) and increasing arterial PCO2 (PaCO2) whilst breathing. End-apnea PaO2 ranged from 23mmHg to 37mmHg (30 ± 7 mmHg). Elevation in mean arterial pressure was greater during apnea than during clamp reaching +54 ± 24% vs 34 ± 26%, respectively ; however, CBF increased similarly between apnea and clamp (93.6 ± 28% and 83.4 ± 38%, respectively). This latter observation indicates that during the overall apnea period IBM per se do not augment CBF and that the brain remains sufficiently protected against hypertension. Termination of apnea was not determined by reduced cerebral oxygen delivery ; despite 40-50% reductions in arterial oxygen content, oxygen delivery was maintained by commensurately increased CBF.
cerebral blood flow ; apnea diving
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Podaci o izdanju
35 (1)
2015.
66-73
objavljeno
0271-678X
1559-7016
10.1038/jcbfm.2014.170
Povezanost rada
Temeljne medicinske znanosti