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Konrad E. Bloch - One of the best experts on this subject based on the ideXlab platform.
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Effect of Breathing Oxygen-Enriched Air on Exercise Performance in Patients with Chronic Obstructive Pulmonary Disease: Randomized, Placebo-Controlled, Cross-Over Trial.
Respiration; international review of thoracic diseases, 2020Co-Authors: Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Konrad E. Bloch, Simon Raphael Schneider, Mona Lichtblau, Esther I. Schwarz, Silvia UlrichAbstract:Background Patients with chronic obstructive pulmonary disease (COPD) experience dyspnea and hypoxemia during exercise. Objective The aim of this study was to evaluate the effects of Breathing Oxygen-enriched air on exercise performance and associated physiological changes in patients with COPD. Methods In a randomized, placebo-controlled, single-blind, cross-over trial, 20 patients with COPD (11 women, age 65 ± 6 years, FEV1 64 ± 19% pred., resting SpO2 ≥90%) performed 4 cycle ergospirometries to exhaustion using an incremental exercise test (IET) and a constant work rate (at 75% maximal workload with air) exercise test (CWRET), each with ambient (FiO2 0.21) and Oxygen-enriched (FiO2 0.5) air. The main outcomes were the change in maximal workload in the IET and the change in exercise duration in the CWRET with Oxygen versus air. Electrocardiogram, pulmonary gas exchange, thoracic volumes by inductance plethysmography, arterial blood gases, and cerebral and quadriceps muscle tissue Oxygenation (CTO and MTO) were additionally measured. Results In the IET, maximal workload increased from 96 ± 21 to 104 ± 28 W with Oxygen. In the CWRET, exercise duration increased from 605 ± 274 to 963 ± 444 s with Oxygen. At end-exercise with Oxygen, CTO, MTO, PaO2, and PaCO2 were increased, while V'E/V'CO2 was reduced and thoracic volumes were similar. At the corresponding time to end of exercise with ambient air, Oxygen decreased heart rate, respiratory rate, minute ventilation, and V'E/V'CO2, while Oxygenation was increased. Conclusion In COPD patients without resting hypoxemia, Breathing Oxygen-enriched air improves exercise performance. This relates to a higher arterial Oxygen saturation promoting Oxygen availability to muscle and cerebral tissue and an enhanced ventilatory efficiency. COPD patients may benefit from Oxygen therapy during exercise training.
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effect of Breathing Oxygen enriched air on exercise performance in patients with precapillary pulmonary hypertension randomized sham controlled cross over trial
European Heart Journal, 2017Co-Authors: Silvia Ulrich, Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Stephan Keusch, Severine Mullermottet, Konrad E. BlochAbstract:Aims The purpose of the current trial was to test the hypothesis that Breathing Oxygen-enriched air increases exercise performance of patients with pulmonary arterial or chronic thrombo-embolic pulmonary hypertension (PAH/CTEPH) and to investigate involved mechanisms. Methods and results Twenty-two patients with PAH/CTEPH, eight women, means ± SD 61 ± 14 years, resting mPAP 35 ± 9mmHg, PaO2 ambient air >7.3 kPa, underwent four bicycle ergospirometries to exhaustion on different days, while Breathing Oxygen-enriched (FiO2 0.50, hyperoxia) or ambient air (FiO2 0.21, normoxia) using progressively increased or constant load protocols (with 75% maximal work rate under FiO2 0.21), according to a randomized, sham-controlled, single-blind, cross-over design. ECG, pulmonary gas-exchange, arterial blood gases, cerebral and quadriceps muscle tissue Oxygenation (CTO and QMTO) by near-infrared spectroscopy were measured. In ramp exercise, maximal work rate increased from 113 ± 38 W with normoxia to 132 ± 48 W with hyperoxia, mean difference 19.7 (95% CI 10.5-28.9) W, P < 0.001. Constant load exercise endurance increased from 571 ± 443 to 1242 ± 514 s, mean difference 671 (95% CI 392-951) s, P < 0.001. At end-exercise with hyperoxia PaO2, CTO, QMTO, and PaCO2 were increased, and ventilatory equivalents for CO2 were reduced while the physiological dead space/tidal volume ratio remained unchanged. Conclusion In patients with PAH/CTEPH, Breathing Oxygen-enriched air provides major increases in exercise performance. This is related to an improved arterial Oxygenation that promotes Oxygen availability in muscles and brain and to a reduction of the excessive ventilatory response to exercise thereby enhancing ventilatory efficiency. Patients with PAH/CTEPH may therefore benefit from Oxygen therapy during daily physical activities and training. Trial registration clinicaltrials.gov Identifier: NCT01748474.
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Effect of Breathing Oxygen-enriched air on exercise performance in patients with precapillary pulmonary hypertension: randomized, sham-controlled cross-over trial.
European heart journal, 2017Co-Authors: Silvia Ulrich, Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Séverine Müller-mottet, Stephan Keusch, Konrad E. BlochAbstract:Aims The purpose of the current trial was to test the hypothesis that Breathing Oxygen-enriched air increases exercise performance of patients with pulmonary arterial or chronic thrombo-embolic pulmonary hypertension (PAH/CTEPH) and to investigate involved mechanisms. Methods and results Twenty-two patients with PAH/CTEPH, eight women, means ± SD 61 ± 14 years, resting mPAP 35 ± 9mmHg, PaO2 ambient air >7.3 kPa, underwent four bicycle ergospirometries to exhaustion on different days, while Breathing Oxygen-enriched (FiO2 0.50, hyperoxia) or ambient air (FiO2 0.21, normoxia) using progressively increased or constant load protocols (with 75% maximal work rate under FiO2 0.21), according to a randomized, sham-controlled, single-blind, cross-over design. ECG, pulmonary gas-exchange, arterial blood gases, cerebral and quadriceps muscle tissue Oxygenation (CTO and QMTO) by near-infrared spectroscopy were measured. In ramp exercise, maximal work rate increased from 113 ± 38 W with normoxia to 132 ± 48 W with hyperoxia, mean difference 19.7 (95% CI 10.5-28.9) W, P
Silvia Ulrich - One of the best experts on this subject based on the ideXlab platform.
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Effect of Breathing Oxygen-Enriched Air on Exercise Performance in Patients with Chronic Obstructive Pulmonary Disease: Randomized, Placebo-Controlled, Cross-Over Trial.
Respiration; international review of thoracic diseases, 2020Co-Authors: Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Konrad E. Bloch, Simon Raphael Schneider, Mona Lichtblau, Esther I. Schwarz, Silvia UlrichAbstract:Background Patients with chronic obstructive pulmonary disease (COPD) experience dyspnea and hypoxemia during exercise. Objective The aim of this study was to evaluate the effects of Breathing Oxygen-enriched air on exercise performance and associated physiological changes in patients with COPD. Methods In a randomized, placebo-controlled, single-blind, cross-over trial, 20 patients with COPD (11 women, age 65 ± 6 years, FEV1 64 ± 19% pred., resting SpO2 ≥90%) performed 4 cycle ergospirometries to exhaustion using an incremental exercise test (IET) and a constant work rate (at 75% maximal workload with air) exercise test (CWRET), each with ambient (FiO2 0.21) and Oxygen-enriched (FiO2 0.5) air. The main outcomes were the change in maximal workload in the IET and the change in exercise duration in the CWRET with Oxygen versus air. Electrocardiogram, pulmonary gas exchange, thoracic volumes by inductance plethysmography, arterial blood gases, and cerebral and quadriceps muscle tissue Oxygenation (CTO and MTO) were additionally measured. Results In the IET, maximal workload increased from 96 ± 21 to 104 ± 28 W with Oxygen. In the CWRET, exercise duration increased from 605 ± 274 to 963 ± 444 s with Oxygen. At end-exercise with Oxygen, CTO, MTO, PaO2, and PaCO2 were increased, while V'E/V'CO2 was reduced and thoracic volumes were similar. At the corresponding time to end of exercise with ambient air, Oxygen decreased heart rate, respiratory rate, minute ventilation, and V'E/V'CO2, while Oxygenation was increased. Conclusion In COPD patients without resting hypoxemia, Breathing Oxygen-enriched air improves exercise performance. This relates to a higher arterial Oxygen saturation promoting Oxygen availability to muscle and cerebral tissue and an enhanced ventilatory efficiency. COPD patients may benefit from Oxygen therapy during exercise training.
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effect of Breathing Oxygen enriched air on exercise performance in patients with precapillary pulmonary hypertension randomized sham controlled cross over trial
European Heart Journal, 2017Co-Authors: Silvia Ulrich, Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Stephan Keusch, Severine Mullermottet, Konrad E. BlochAbstract:Aims The purpose of the current trial was to test the hypothesis that Breathing Oxygen-enriched air increases exercise performance of patients with pulmonary arterial or chronic thrombo-embolic pulmonary hypertension (PAH/CTEPH) and to investigate involved mechanisms. Methods and results Twenty-two patients with PAH/CTEPH, eight women, means ± SD 61 ± 14 years, resting mPAP 35 ± 9mmHg, PaO2 ambient air >7.3 kPa, underwent four bicycle ergospirometries to exhaustion on different days, while Breathing Oxygen-enriched (FiO2 0.50, hyperoxia) or ambient air (FiO2 0.21, normoxia) using progressively increased or constant load protocols (with 75% maximal work rate under FiO2 0.21), according to a randomized, sham-controlled, single-blind, cross-over design. ECG, pulmonary gas-exchange, arterial blood gases, cerebral and quadriceps muscle tissue Oxygenation (CTO and QMTO) by near-infrared spectroscopy were measured. In ramp exercise, maximal work rate increased from 113 ± 38 W with normoxia to 132 ± 48 W with hyperoxia, mean difference 19.7 (95% CI 10.5-28.9) W, P < 0.001. Constant load exercise endurance increased from 571 ± 443 to 1242 ± 514 s, mean difference 671 (95% CI 392-951) s, P < 0.001. At end-exercise with hyperoxia PaO2, CTO, QMTO, and PaCO2 were increased, and ventilatory equivalents for CO2 were reduced while the physiological dead space/tidal volume ratio remained unchanged. Conclusion In patients with PAH/CTEPH, Breathing Oxygen-enriched air provides major increases in exercise performance. This is related to an improved arterial Oxygenation that promotes Oxygen availability in muscles and brain and to a reduction of the excessive ventilatory response to exercise thereby enhancing ventilatory efficiency. Patients with PAH/CTEPH may therefore benefit from Oxygen therapy during daily physical activities and training. Trial registration clinicaltrials.gov Identifier: NCT01748474.
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Effect of Breathing Oxygen-enriched air on exercise performance in patients with precapillary pulmonary hypertension: randomized, sham-controlled cross-over trial.
European heart journal, 2017Co-Authors: Silvia Ulrich, Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Séverine Müller-mottet, Stephan Keusch, Konrad E. BlochAbstract:Aims The purpose of the current trial was to test the hypothesis that Breathing Oxygen-enriched air increases exercise performance of patients with pulmonary arterial or chronic thrombo-embolic pulmonary hypertension (PAH/CTEPH) and to investigate involved mechanisms. Methods and results Twenty-two patients with PAH/CTEPH, eight women, means ± SD 61 ± 14 years, resting mPAP 35 ± 9mmHg, PaO2 ambient air >7.3 kPa, underwent four bicycle ergospirometries to exhaustion on different days, while Breathing Oxygen-enriched (FiO2 0.50, hyperoxia) or ambient air (FiO2 0.21, normoxia) using progressively increased or constant load protocols (with 75% maximal work rate under FiO2 0.21), according to a randomized, sham-controlled, single-blind, cross-over design. ECG, pulmonary gas-exchange, arterial blood gases, cerebral and quadriceps muscle tissue Oxygenation (CTO and QMTO) by near-infrared spectroscopy were measured. In ramp exercise, maximal work rate increased from 113 ± 38 W with normoxia to 132 ± 48 W with hyperoxia, mean difference 19.7 (95% CI 10.5-28.9) W, P
Iven H. Young - One of the best experts on this subject based on the ideXlab platform.
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the role of hypoventilation and ventilation perfusion redistribution in Oxygen induced hypercapnia during acute exacerbations of chronic obstructive pulmonary disease
American Journal of Respiratory and Critical Care Medicine, 2000Co-Authors: Tracey D. Robinson, David B. Freiberg, Jeff A. Regnis, Iven H. YoungAbstract:The detailed mechanisms of Oxygen-induced hypercapnia were examined in 22 patients during an acute exacerbation of chronic obstructive pulmonary disease. Ventilation, cardiac output, and the distribution of ventilation-perfusion (V˙ a/Q˙ ) ratios were measured using the multiple inert gas elimination technique Breathing air and then 100% Oxygen through a nose mask. Twelve patients were classified as retainers (R) when PaCO2 rose by more than 3 mm Hg (8.3 ± 5.6; mean ± SD) after Breathing 100% Oxygen for at least 20 min. The other 10 patients showed a change in PaCO2 of − 1.3 ± 2.2 mm Hg Breathing Oxygen and were classified as nonretainers (NR). Ventilation fell significantly from 9.0 ± 1.5 to 7.2 ± 1.2 L/min in the R group Breathing Oxygen (p = 0.007), whereas there was no change in ventilation in the NR group (9.8 ± 1.8 to 9.9 ± 1.8 L/min). The dispersion of V˙ a/Q˙ ratios as measured by log SD of blood flow (log SD Q˙) increased significantly in both R (0.96 ± 0.17 to 1.13 ± 0.17) and NR (0.77 ± 0.20 to...
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The Role of Hypoventilation and Ventilation-Perfusion Redistribution in Oxygen-induced Hypercapnia during Acute Exacerbations of Chronic Obstructive Pulmonary Disease
American journal of respiratory and critical care medicine, 2000Co-Authors: Tracey D. Robinson, David B. Freiberg, Jeff A. Regnis, Iven H. YoungAbstract:The detailed mechanisms of Oxygen-induced hypercapnia were examined in 22 patients during an acute exacerbation of chronic obstructive pulmonary disease. Ventilation, cardiac output, and the distribution of ventilation-perfusion (V A/Q ) ratios were measured using the multiple inert gas elimination technique Breathing air and then 100% Oxygen through a nose mask. Twelve patients were classified as retainers (R) when Pa(CO(2)) rose by more than 3 mm Hg (8.3 +/- 5.6; mean +/- SD) after Breathing 100% Oxygen for at least 20 min. The other 10 patients showed a change in Pa(CO(2)) of -1.3 +/- 2.2 mm Hg Breathing Oxygen and were classified as nonretainers (NR). Ventilation fell significantly from 9.0 +/- 1.5 to 7.2 +/- 1.2 L/min in the R group Breathing Oxygen (p = 0.007), whereas there was no change in ventilation in the NR group (9.8 +/- 1.8 to 9.9 +/- 1.8 L/min). The dispersion of V A/Q ratios as measured by log SD of blood flow (log SD Q) increased significantly in both R (0.96 +/- 0. 17 to 1.13 +/- 0.17) and NR (0.77 +/- 0.20 to 1.04 +/- 0.23, p < 0.05) groups Breathing Oxygen, whereas log SD of ventilation (log SD Q ) increased only in the R group (0.97 +/- 0.24 to 1.20 +/- 0.46, p < 0.05). This study suggests that an overall reduction in ventilation characterizes Oxygen-induced hypercapnia, as an increased dispersion of blood flow from release of hypoxic vasoconstriction occurred to a significant and similar degree in both groups. The significant increase in wasted ventilation (alveolar dead space) in the R group only may be secondary to the higher carbon dioxide tension, perhaps related to bronchodilatation.
Elisabeth Hasler - One of the best experts on this subject based on the ideXlab platform.
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Effect of Breathing Oxygen-Enriched Air on Exercise Performance in Patients with Chronic Obstructive Pulmonary Disease: Randomized, Placebo-Controlled, Cross-Over Trial.
Respiration; international review of thoracic diseases, 2020Co-Authors: Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Konrad E. Bloch, Simon Raphael Schneider, Mona Lichtblau, Esther I. Schwarz, Silvia UlrichAbstract:Background Patients with chronic obstructive pulmonary disease (COPD) experience dyspnea and hypoxemia during exercise. Objective The aim of this study was to evaluate the effects of Breathing Oxygen-enriched air on exercise performance and associated physiological changes in patients with COPD. Methods In a randomized, placebo-controlled, single-blind, cross-over trial, 20 patients with COPD (11 women, age 65 ± 6 years, FEV1 64 ± 19% pred., resting SpO2 ≥90%) performed 4 cycle ergospirometries to exhaustion using an incremental exercise test (IET) and a constant work rate (at 75% maximal workload with air) exercise test (CWRET), each with ambient (FiO2 0.21) and Oxygen-enriched (FiO2 0.5) air. The main outcomes were the change in maximal workload in the IET and the change in exercise duration in the CWRET with Oxygen versus air. Electrocardiogram, pulmonary gas exchange, thoracic volumes by inductance plethysmography, arterial blood gases, and cerebral and quadriceps muscle tissue Oxygenation (CTO and MTO) were additionally measured. Results In the IET, maximal workload increased from 96 ± 21 to 104 ± 28 W with Oxygen. In the CWRET, exercise duration increased from 605 ± 274 to 963 ± 444 s with Oxygen. At end-exercise with Oxygen, CTO, MTO, PaO2, and PaCO2 were increased, while V'E/V'CO2 was reduced and thoracic volumes were similar. At the corresponding time to end of exercise with ambient air, Oxygen decreased heart rate, respiratory rate, minute ventilation, and V'E/V'CO2, while Oxygenation was increased. Conclusion In COPD patients without resting hypoxemia, Breathing Oxygen-enriched air improves exercise performance. This relates to a higher arterial Oxygen saturation promoting Oxygen availability to muscle and cerebral tissue and an enhanced ventilatory efficiency. COPD patients may benefit from Oxygen therapy during exercise training.
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effect of Breathing Oxygen enriched air on exercise performance in patients with precapillary pulmonary hypertension randomized sham controlled cross over trial
European Heart Journal, 2017Co-Authors: Silvia Ulrich, Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Stephan Keusch, Severine Mullermottet, Konrad E. BlochAbstract:Aims The purpose of the current trial was to test the hypothesis that Breathing Oxygen-enriched air increases exercise performance of patients with pulmonary arterial or chronic thrombo-embolic pulmonary hypertension (PAH/CTEPH) and to investigate involved mechanisms. Methods and results Twenty-two patients with PAH/CTEPH, eight women, means ± SD 61 ± 14 years, resting mPAP 35 ± 9mmHg, PaO2 ambient air >7.3 kPa, underwent four bicycle ergospirometries to exhaustion on different days, while Breathing Oxygen-enriched (FiO2 0.50, hyperoxia) or ambient air (FiO2 0.21, normoxia) using progressively increased or constant load protocols (with 75% maximal work rate under FiO2 0.21), according to a randomized, sham-controlled, single-blind, cross-over design. ECG, pulmonary gas-exchange, arterial blood gases, cerebral and quadriceps muscle tissue Oxygenation (CTO and QMTO) by near-infrared spectroscopy were measured. In ramp exercise, maximal work rate increased from 113 ± 38 W with normoxia to 132 ± 48 W with hyperoxia, mean difference 19.7 (95% CI 10.5-28.9) W, P < 0.001. Constant load exercise endurance increased from 571 ± 443 to 1242 ± 514 s, mean difference 671 (95% CI 392-951) s, P < 0.001. At end-exercise with hyperoxia PaO2, CTO, QMTO, and PaCO2 were increased, and ventilatory equivalents for CO2 were reduced while the physiological dead space/tidal volume ratio remained unchanged. Conclusion In patients with PAH/CTEPH, Breathing Oxygen-enriched air provides major increases in exercise performance. This is related to an improved arterial Oxygenation that promotes Oxygen availability in muscles and brain and to a reduction of the excessive ventilatory response to exercise thereby enhancing ventilatory efficiency. Patients with PAH/CTEPH may therefore benefit from Oxygen therapy during daily physical activities and training. Trial registration clinicaltrials.gov Identifier: NCT01748474.
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Effect of Breathing Oxygen-enriched air on exercise performance in patients with precapillary pulmonary hypertension: randomized, sham-controlled cross-over trial.
European heart journal, 2017Co-Authors: Silvia Ulrich, Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Séverine Müller-mottet, Stephan Keusch, Konrad E. BlochAbstract:Aims The purpose of the current trial was to test the hypothesis that Breathing Oxygen-enriched air increases exercise performance of patients with pulmonary arterial or chronic thrombo-embolic pulmonary hypertension (PAH/CTEPH) and to investigate involved mechanisms. Methods and results Twenty-two patients with PAH/CTEPH, eight women, means ± SD 61 ± 14 years, resting mPAP 35 ± 9mmHg, PaO2 ambient air >7.3 kPa, underwent four bicycle ergospirometries to exhaustion on different days, while Breathing Oxygen-enriched (FiO2 0.50, hyperoxia) or ambient air (FiO2 0.21, normoxia) using progressively increased or constant load protocols (with 75% maximal work rate under FiO2 0.21), according to a randomized, sham-controlled, single-blind, cross-over design. ECG, pulmonary gas-exchange, arterial blood gases, cerebral and quadriceps muscle tissue Oxygenation (CTO and QMTO) by near-infrared spectroscopy were measured. In ramp exercise, maximal work rate increased from 113 ± 38 W with normoxia to 132 ± 48 W with hyperoxia, mean difference 19.7 (95% CI 10.5-28.9) W, P
Michael Furian - One of the best experts on this subject based on the ideXlab platform.
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Effect of Breathing Oxygen-Enriched Air on Exercise Performance in Patients with Chronic Obstructive Pulmonary Disease: Randomized, Placebo-Controlled, Cross-Over Trial.
Respiration; international review of thoracic diseases, 2020Co-Authors: Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Konrad E. Bloch, Simon Raphael Schneider, Mona Lichtblau, Esther I. Schwarz, Silvia UlrichAbstract:Background Patients with chronic obstructive pulmonary disease (COPD) experience dyspnea and hypoxemia during exercise. Objective The aim of this study was to evaluate the effects of Breathing Oxygen-enriched air on exercise performance and associated physiological changes in patients with COPD. Methods In a randomized, placebo-controlled, single-blind, cross-over trial, 20 patients with COPD (11 women, age 65 ± 6 years, FEV1 64 ± 19% pred., resting SpO2 ≥90%) performed 4 cycle ergospirometries to exhaustion using an incremental exercise test (IET) and a constant work rate (at 75% maximal workload with air) exercise test (CWRET), each with ambient (FiO2 0.21) and Oxygen-enriched (FiO2 0.5) air. The main outcomes were the change in maximal workload in the IET and the change in exercise duration in the CWRET with Oxygen versus air. Electrocardiogram, pulmonary gas exchange, thoracic volumes by inductance plethysmography, arterial blood gases, and cerebral and quadriceps muscle tissue Oxygenation (CTO and MTO) were additionally measured. Results In the IET, maximal workload increased from 96 ± 21 to 104 ± 28 W with Oxygen. In the CWRET, exercise duration increased from 605 ± 274 to 963 ± 444 s with Oxygen. At end-exercise with Oxygen, CTO, MTO, PaO2, and PaCO2 were increased, while V'E/V'CO2 was reduced and thoracic volumes were similar. At the corresponding time to end of exercise with ambient air, Oxygen decreased heart rate, respiratory rate, minute ventilation, and V'E/V'CO2, while Oxygenation was increased. Conclusion In COPD patients without resting hypoxemia, Breathing Oxygen-enriched air improves exercise performance. This relates to a higher arterial Oxygen saturation promoting Oxygen availability to muscle and cerebral tissue and an enhanced ventilatory efficiency. COPD patients may benefit from Oxygen therapy during exercise training.
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effect of Breathing Oxygen enriched air on exercise performance in patients with precapillary pulmonary hypertension randomized sham controlled cross over trial
European Heart Journal, 2017Co-Authors: Silvia Ulrich, Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Stephan Keusch, Severine Mullermottet, Konrad E. BlochAbstract:Aims The purpose of the current trial was to test the hypothesis that Breathing Oxygen-enriched air increases exercise performance of patients with pulmonary arterial or chronic thrombo-embolic pulmonary hypertension (PAH/CTEPH) and to investigate involved mechanisms. Methods and results Twenty-two patients with PAH/CTEPH, eight women, means ± SD 61 ± 14 years, resting mPAP 35 ± 9mmHg, PaO2 ambient air >7.3 kPa, underwent four bicycle ergospirometries to exhaustion on different days, while Breathing Oxygen-enriched (FiO2 0.50, hyperoxia) or ambient air (FiO2 0.21, normoxia) using progressively increased or constant load protocols (with 75% maximal work rate under FiO2 0.21), according to a randomized, sham-controlled, single-blind, cross-over design. ECG, pulmonary gas-exchange, arterial blood gases, cerebral and quadriceps muscle tissue Oxygenation (CTO and QMTO) by near-infrared spectroscopy were measured. In ramp exercise, maximal work rate increased from 113 ± 38 W with normoxia to 132 ± 48 W with hyperoxia, mean difference 19.7 (95% CI 10.5-28.9) W, P < 0.001. Constant load exercise endurance increased from 571 ± 443 to 1242 ± 514 s, mean difference 671 (95% CI 392-951) s, P < 0.001. At end-exercise with hyperoxia PaO2, CTO, QMTO, and PaCO2 were increased, and ventilatory equivalents for CO2 were reduced while the physiological dead space/tidal volume ratio remained unchanged. Conclusion In patients with PAH/CTEPH, Breathing Oxygen-enriched air provides major increases in exercise performance. This is related to an improved arterial Oxygenation that promotes Oxygen availability in muscles and brain and to a reduction of the excessive ventilatory response to exercise thereby enhancing ventilatory efficiency. Patients with PAH/CTEPH may therefore benefit from Oxygen therapy during daily physical activities and training. Trial registration clinicaltrials.gov Identifier: NCT01748474.
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Effect of Breathing Oxygen-enriched air on exercise performance in patients with precapillary pulmonary hypertension: randomized, sham-controlled cross-over trial.
European heart journal, 2017Co-Authors: Silvia Ulrich, Elisabeth Hasler, Stéphanie Saxer, Michael Furian, Séverine Müller-mottet, Stephan Keusch, Konrad E. BlochAbstract:Aims The purpose of the current trial was to test the hypothesis that Breathing Oxygen-enriched air increases exercise performance of patients with pulmonary arterial or chronic thrombo-embolic pulmonary hypertension (PAH/CTEPH) and to investigate involved mechanisms. Methods and results Twenty-two patients with PAH/CTEPH, eight women, means ± SD 61 ± 14 years, resting mPAP 35 ± 9mmHg, PaO2 ambient air >7.3 kPa, underwent four bicycle ergospirometries to exhaustion on different days, while Breathing Oxygen-enriched (FiO2 0.50, hyperoxia) or ambient air (FiO2 0.21, normoxia) using progressively increased or constant load protocols (with 75% maximal work rate under FiO2 0.21), according to a randomized, sham-controlled, single-blind, cross-over design. ECG, pulmonary gas-exchange, arterial blood gases, cerebral and quadriceps muscle tissue Oxygenation (CTO and QMTO) by near-infrared spectroscopy were measured. In ramp exercise, maximal work rate increased from 113 ± 38 W with normoxia to 132 ± 48 W with hyperoxia, mean difference 19.7 (95% CI 10.5-28.9) W, P