Details

Autor(en) / Beteiligte

• Cherry, A D
• kner, I F
• Frederick, H J
• Natoli, M J
• Schinazi, E A
• Longphre, J P
• Conard, J L
• White, W D
• Freiberger, J J
• Stolp, B W
• Pollock, N W
• Doar, P O
• Boso, A E
• Alford, E L
• Walker, A J
• Ma, A C
• Rhodes, M A
• Moon, R E

Titel

Predictors of increased Pa^sub CO2^ during immersed prone exercise at 4.7 ATA

Ist Teil von

• Journal of applied physiology (1985), 2009-01, Vol.106 (1), p.316

Ort / Verlag

Bethesda: American Physiological Society

Erscheinungsjahr

2009

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• During diving, arterial P... (Pa...) levels can increase and contribute to psychomotor impairment and unconsciousness. This study was designed to investigate the effects of the hypercapnic ventilatory response (HCVR), exercise, inspired P..., and externally applied transrespiratory pressure (P...) on Pa... during immersed prone exercise in subjects breathing oxygen-nitrogen mixes at 4.7 ATA. Twenty-five subjects were studied at rest and during 6 min of exercise while dry and submersed at 1 ATA and during exercise submersed at 4.7 ATA. At 4.7 ATA, subsets of the 25 subjects (9-10 for each condition) exercised as P... was varied between +10, 0, and -10 cmH...O; breathing gas P... was 0.7, 1.0, and 1.3 ATA; and inspiratory and expiratory breathing resistances were varied using 14.9-, 11.6-, and 10.2-mm-diameter-aperture disks. During exercise, Pa... (Torr) increased from 31.5 ± 4.1 (mean ± SD for all subjects) dry to 34.2 ± 4.8 (P = 0.02) submersed, to 46.1 ± 5.9 (P < 0.001) at 4.7 ATA during air breathing and to 49.9 ± 5.4 (P < 0.001 vs. 1 ATA) during breathing with high external resistance. There was no significant effect of inspired P... or P... on Pa... or minute ventilation (...E). ...E (l/min) decreased from 89.2 ± 22.9 dry to 76.3 ± 20.5 (P = 0.02) submersed, to 61.6 ± 13.9 (P < 0.001) at 4.7 ATA during air breathing and to 49.2 ± 7.3 (P < 0.001) during breathing with resistance. We conclude that the major contributors to increased Pa... during exercise at 4.7 ATA are increased depth and external respiratory resistance. HCVR and maximal O... consumption were also weakly predictive. The effects of P..., inspired P..., and O... consumption during short-term exercise were not significant. (ProQuest: ... denotes formulae/symbols omitted.)