Exercise tolerance with helium-hyperoxia<i>versus</i>hyperoxia in hypoxaemic patients with COPD

Queiroga, Fernando Ramos; Nunes, Marco Antônio Prado; Meda, E; Chiappa, Gaspar R.; Machado, Maria Christina Lombardi Oliveira; Nery, Luíz Eduardo; Neder, J. Alberto

doi:10.1183/09031936.00087812

Cited by 15 publications

(11 citation statements)

References 42 publications

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“…These studies all found significant differences in endurance time in favor of the hyperoxic helium group 173–175. They further demonstrated reductions in the resistive work of breathing,173 and reductions in exercise-induced dynamic hyperinflation (increases in EELV)174,175 in comparison with hyperoxia alone.…”

Section: Management and Treatment Of Hyperinflationmentioning

confidence: 79%

“…The response with regard to exercise capacity seems to be correlated with the magnitude of change in EELV during exercise 171. In three studies, the responses to hyperoxic helium (60%–70% helium, 30%–40% oxygen) and oxygen supplementation alone were compared during a constant load cycling task in patients with moderate (nonhypoxemic),173 severe,174 and very severe (on long-term oxygen therapy) symptoms 175. These studies all found significant differences in endurance time in favor of the hyperoxic helium group 173–175.…”

Section: Management and Treatment Of Hyperinflationmentioning

confidence: 99%

“…In three studies, the responses to hyperoxic helium (60%–70% helium, 30%–40% oxygen) and oxygen supplementation alone were compared during a constant load cycling task in patients with moderate (nonhypoxemic),173 severe,174 and very severe (on long-term oxygen therapy) symptoms 175. These studies all found significant differences in endurance time in favor of the hyperoxic helium group 173–175. They further demonstrated reductions in the resistive work of breathing,173 and reductions in exercise-induced dynamic hyperinflation (increases in EELV)174,175 in comparison with hyperoxia alone.…”

Section: Management and Treatment Of Hyperinflationmentioning

confidence: 99%

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Pathogenesis of hyperinflation in chronic obstructive pulmonary disease

Gagnon¹,

Guenette²,

Langer³

et al. 2014

COPD

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Chronic obstructive pulmonary disease (COPD) is a preventable and treatable lung disease characterized by airflow limitation that is not fully reversible. In a significant proportion of patients with COPD, reduced lung elastic recoil combined with expiratory flow limitation leads to lung hyperinflation during the course of the disease. Development of hyperinflation during the course of COPD is insidious. Dynamic hyperinflation is highly prevalent in the advanced stages of COPD, and new evidence suggests that it also occurs in many patients with mild disease, independently of the presence of resting hyperinflation. Hyperinflation is clinically relevant for patients with COPD mainly because it contributes to dyspnea, exercise intolerance, skeletal muscle limitations, morbidity, and reduced physical activity levels associated with the disease. Various pharmacological and nonpharmacological interventions have been shown to reduce hyperinflation and delay the onset of ventilatory limitation in patients with COPD. The aim of this review is to address the more recent literature regarding the pathogenesis, assessment, and management of both static and dynamic lung hyperinflation in patients with COPD. We also address the influence of biological sex and obesity and new developments in our understanding of hyperinflation in patients with mild COPD and its evolution during progression of the disease.

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Section: Management and Treatment Of Hyperinflationmentioning

confidence: 79%

Section: Management and Treatment Of Hyperinflationmentioning

confidence: 99%

Section: Management and Treatment Of Hyperinflationmentioning

confidence: 99%

See 1 more Smart Citation

Pathogenesis of hyperinflation in chronic obstructive pulmonary disease

Gagnon¹,

Guenette²,

Langer³

et al. 2014

COPD

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“…Moderate hyperoxic gas inspiration can avoid or soften acute mountain sickness while mountaineering [ 53 ]. Therapeutic hyperoxia has been reported to be available for patients with chronic obstructive pulmonary disease [ 54 ]. It is interesting to note that the cardiorespiratory and/or muscular responses during exercise under hyperoxia exhibited large individual differences [ 28 , 50 , 54 ].…”

Section: Discussionmentioning

confidence: 99%

Energy cost and lower leg muscle activities during erect bipedal locomotion under hyperoxia

Abe

Fukuoka

Maeda

et al. 2018

J Physiol Anthropol

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BackgroundEnergy cost of transport per unit distance (CoT) against speed shows U-shaped fashion in walking and linear fashion in running, indicating that there exists a specific walking speed minimizing the CoT, being defined as economical speed (ES). Another specific gait speed is the intersection speed between both fashions, being called energetically optimal transition speed (EOTS). We measured the ES, EOTS, and muscle activities during walking and running at the EOTS under hyperoxia (40% fraction of inspired oxygen) on the level and uphill gradients (+ 5%).MethodsOxygen consumption and carbon dioxide output were measured to calculate the CoT values at eight walking speeds (2.4–7.3 km h−1) and four running speeds (7.3–9.4 km h− 1) in 17 young males. Electromyography was recorded from gastrocnemius medialis, gastrocnemius lateralis (GL), and tibialis anterior (TA) to evaluate muscle activities. Mean power frequency (MPF) was obtained to compare motor unit recruitment patterns between walking and running.Results, , and CoT values were lower under hyperoxia than normoxia at faster walking speeds and any running speeds. A faster ES on the uphill gradient and slower EOTS on both gradients were observed under hyperoxia than normoxia. GL and TA activities became lower when switching from walking to running at the EOTS under both FiO2 conditions on both gradients, so did the MPF in the TA.ConclusionsES and EOTS were influenced by reduced metabolic demands induced by hyperoxia. GL and TA activities in association with a lower shift of motor unit recruitment patterns in the TA would be related to the gait selection when walking or running at the EOTS.Trial registrationUMIN000017690 (R000020501). Registered May 26, 2015, before the first trial.Electronic supplementary materialThe online version of this article (10.1186/s40101-018-0177-7) contains supplementary material, which is available to authorized users.

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“…The effects of interventions on ventilatory efficiency have been helpful to uncover the underlying mechanisms of exercise intolerance and dyspnoea in COPD while providing a physiological rationale for their main mechanism of action. For instance, interventions primarily aimed at releasing the mechanical constraints (heliox [55,59,60,65], lobectomy [58], and bronchodilators [54,56,64]) increased V′E at a given V′CO 2 . These findings fit well with the concept that an increased slope of the V′E−V′CO 2 relationship should not be uniformly interpreted as indicative of poor ventilatory efficiency in advanced COPD, at least from a "quantitative" perspective.…”

Section: Effects Of Interventionsmentioning

confidence: 99%

Physiological and clinical relevance of exercise ventilatory efficiency in COPD

et al. 2017

Self Cite

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Exercise ventilation (') relative to carbon dioxide output (' ) is particularly relevant to patients limited by the respiratory system, those with chronic obstructive pulmonary disease (COPD). High'-' (poor ventilatory efficiency) has been found to be a key physiological abnormality in symptomatic patients with largely preserved forced expiratory volume in 1 s (FEV). Establishing an association between high '-' and exertional dyspnoea in mild COPD provides evidence that exercise intolerance is not a mere consequence of detraining. As the disease evolves, poor ventilatory efficiency might help explaining "out-of-proportion" breathlessness (to FEV impairment). Regardless, disease severity, cardiocirculatory co-morbidities such as heart failure and pulmonary hypertension have been found to increase '-' In fact, a high '-' has been found to be a powerful predictor of poor outcome in lung resection surgery. Moreover, a high '-' has added value to resting lung hyperinflation in predicting all-cause and respiratory mortality across the spectrum of COPD severity. Documenting improved ventilatory efficiency after lung transplantation and lung volume reduction surgery provides objective evidence of treatment efficacy. Considering the usefulness of exercise ventilatory efficiency in different clinical scenarios, the '-' relationship should be valued in the interpretation of cardiopulmonary exercise tests in patients with mild-to-end-stage COPD.

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Exercise tolerance with helium-hyperoxiaversushyperoxia in hypoxaemic patients with COPD

Cited by 15 publications

References 42 publications

Pathogenesis of hyperinflation in chronic obstructive pulmonary disease

Pathogenesis of hyperinflation in chronic obstructive pulmonary disease

Energy cost and lower leg muscle activities during erect bipedal locomotion under hyperoxia

Physiological and clinical relevance of exercise ventilatory efficiency in COPD

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