Effect of acute hypoxia on respiratory muscle fatigue in healthy humans
<p>Abstract</p> <p>Background</p> <p>Greater diaphragm fatigue has been reported after hypoxic versus normoxic exercise, but whether this is due to increased ventilation and therefore work of breathing or reduced blood oxygenation per se remains unclear. Hence, we asses...
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| Format: | Article |
| Language: | English |
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BMC
2010-08-01
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| Series: | Respiratory Research |
| Online Access: | http://respiratory-research.com/content/11/1/109 |
| _version_ | 1811251615438471168 |
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| author | Verges Samuel Bachasson Damien Wuyam Bernard |
| author_facet | Verges Samuel Bachasson Damien Wuyam Bernard |
| author_sort | Verges Samuel |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Greater diaphragm fatigue has been reported after hypoxic versus normoxic exercise, but whether this is due to increased ventilation and therefore work of breathing or reduced blood oxygenation per se remains unclear. Hence, we assessed the effect of different blood oxygenation level on isolated hyperpnoea-induced inspiratory and expiratory muscle fatigue.</p> <p>Methods</p> <p>Twelve healthy males performed three 15-min isocapnic hyperpnoea tests (85% of maximum voluntary ventilation with controlled breathing pattern) in normoxic, hypoxic (SpO<sub>2 </sub>= 80%) and hyperoxic (FiO<sub>2 </sub>= 0.60) conditions, in a random order. Before, immediately after and 30 min after hyperpnoea, transdiaphragmatic pressure (P<sub>di,tw </sub>) was measured during cervical magnetic stimulation to assess diaphragm contractility, and gastric pressure (P<sub>ga,tw </sub>) was measured during thoracic magnetic stimulation to assess abdominal muscle contractility. Two-way analysis of variance (time x condition) was used to compare hyperpnoea-induced respiratory muscle fatigue between conditions.</p> <p>Results</p> <p>Hypoxia enhanced hyperpnoea-induced P<sub>di,tw </sub>and P<sub>ga,tw </sub>reductions both immediately after hyperpnoea (P<sub>di,tw </sub>: normoxia -22 ± 7% vs hypoxia -34 ± 8% vs hyperoxia -21 ± 8%; P<sub>ga,tw </sub>: normoxia -17 ± 7% vs hypoxia -26 ± 10% vs hyperoxia -16 ± 11%; all <it>P </it>< 0.05) and after 30 min of recovery (P<sub>di,tw </sub>: normoxia -10 ± 7% vs hypoxia -16 ± 8% vs hyperoxia -8 ± 7%; P<sub>ga,tw </sub>: normoxia -13 ± 6% vs hypoxia -21 ± 9% vs hyperoxia -12 ± 12%; all <it>P </it>< 0.05). No significant difference in P<sub>di,tw </sub>or P<sub>ga,tw </sub>reductions was observed between normoxic and hyperoxic conditions. Also, heart rate and blood lactate concentration during hyperpnoea were higher in hypoxia compared to normoxia and hyperoxia.</p> <p>Conclusions</p> <p>These results demonstrate that hypoxia exacerbates both diaphragm and abdominal muscle fatigability. These results emphasize the potential role of respiratory muscle fatigue in exercise performance limitation under conditions coupling increased work of breathing and reduced O<sub>2 </sub>transport as during exercise in altitude or in hypoxemic patients.</p> |
| first_indexed | 2024-04-12T16:22:13Z |
| format | Article |
| id | doaj.art-ba07f5f3c3494e08a0dddeacd32a9a93 |
| institution | Directory Open Access Journal |
| issn | 1465-9921 |
| language | English |
| last_indexed | 2024-04-12T16:22:13Z |
| publishDate | 2010-08-01 |
| publisher | BMC |
| record_format | Article |
| series | Respiratory Research |
| spelling | doaj.art-ba07f5f3c3494e08a0dddeacd32a9a932022-12-22T03:25:31ZengBMCRespiratory Research1465-99212010-08-0111110910.1186/1465-9921-11-109Effect of acute hypoxia on respiratory muscle fatigue in healthy humansVerges SamuelBachasson DamienWuyam Bernard<p>Abstract</p> <p>Background</p> <p>Greater diaphragm fatigue has been reported after hypoxic versus normoxic exercise, but whether this is due to increased ventilation and therefore work of breathing or reduced blood oxygenation per se remains unclear. Hence, we assessed the effect of different blood oxygenation level on isolated hyperpnoea-induced inspiratory and expiratory muscle fatigue.</p> <p>Methods</p> <p>Twelve healthy males performed three 15-min isocapnic hyperpnoea tests (85% of maximum voluntary ventilation with controlled breathing pattern) in normoxic, hypoxic (SpO<sub>2 </sub>= 80%) and hyperoxic (FiO<sub>2 </sub>= 0.60) conditions, in a random order. Before, immediately after and 30 min after hyperpnoea, transdiaphragmatic pressure (P<sub>di,tw </sub>) was measured during cervical magnetic stimulation to assess diaphragm contractility, and gastric pressure (P<sub>ga,tw </sub>) was measured during thoracic magnetic stimulation to assess abdominal muscle contractility. Two-way analysis of variance (time x condition) was used to compare hyperpnoea-induced respiratory muscle fatigue between conditions.</p> <p>Results</p> <p>Hypoxia enhanced hyperpnoea-induced P<sub>di,tw </sub>and P<sub>ga,tw </sub>reductions both immediately after hyperpnoea (P<sub>di,tw </sub>: normoxia -22 ± 7% vs hypoxia -34 ± 8% vs hyperoxia -21 ± 8%; P<sub>ga,tw </sub>: normoxia -17 ± 7% vs hypoxia -26 ± 10% vs hyperoxia -16 ± 11%; all <it>P </it>< 0.05) and after 30 min of recovery (P<sub>di,tw </sub>: normoxia -10 ± 7% vs hypoxia -16 ± 8% vs hyperoxia -8 ± 7%; P<sub>ga,tw </sub>: normoxia -13 ± 6% vs hypoxia -21 ± 9% vs hyperoxia -12 ± 12%; all <it>P </it>< 0.05). No significant difference in P<sub>di,tw </sub>or P<sub>ga,tw </sub>reductions was observed between normoxic and hyperoxic conditions. Also, heart rate and blood lactate concentration during hyperpnoea were higher in hypoxia compared to normoxia and hyperoxia.</p> <p>Conclusions</p> <p>These results demonstrate that hypoxia exacerbates both diaphragm and abdominal muscle fatigability. These results emphasize the potential role of respiratory muscle fatigue in exercise performance limitation under conditions coupling increased work of breathing and reduced O<sub>2 </sub>transport as during exercise in altitude or in hypoxemic patients.</p>http://respiratory-research.com/content/11/1/109 |
| spellingShingle | Verges Samuel Bachasson Damien Wuyam Bernard Effect of acute hypoxia on respiratory muscle fatigue in healthy humans Respiratory Research |
| title | Effect of acute hypoxia on respiratory muscle fatigue in healthy humans |
| title_full | Effect of acute hypoxia on respiratory muscle fatigue in healthy humans |
| title_fullStr | Effect of acute hypoxia on respiratory muscle fatigue in healthy humans |
| title_full_unstemmed | Effect of acute hypoxia on respiratory muscle fatigue in healthy humans |
| title_short | Effect of acute hypoxia on respiratory muscle fatigue in healthy humans |
| title_sort | effect of acute hypoxia on respiratory muscle fatigue in healthy humans |
| url | http://respiratory-research.com/content/11/1/109 |
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