Topic
Dynamic hyperinflation
About: Dynamic hyperinflation is a research topic. Over the lifetime, 575 publications have been published within this topic receiving 20446 citations. The topic is also known as: Hyperinflation of lung.
Papers published on a yearly basis
Papers
TL;DR: Assessment of whether a 9-week pulmonary rehabilitation program may affect cardiovascular response to exercise in COPD patients shows a significant improvement in maximal exercise tolerance, such as peak oxygen uptake, and in some cardiovascular parameters following rehabilitation, supporting the reported positive effect of physical exercise on muscle function.
Abstract: nificantly reduces odds of hospital admissions and deaths following acute exacerbations, as well as consistently improves the quality of life and exercise tolerance of COPD patients [6] . However, no prospective studies on the role of physical rehabilitation in influencing the number and severity of future exacerbations have been performed yet. The paper by Ramponi et al. [7] , published in this issue of Respiration , aims to assess whether a 9-week pulmonary rehabilitation program may affect cardiovascular response to exercise in COPD patients. In an observational prospective trial, according to the ATS/ERS recommendations, 27 patients with COPD were referred to a rehabilitation program consisting of 3-hour sessions, three times a week, with a minimum of 21 sessions required. Data obtained show a significant improvement in maximal exercise tolerance, such as peak oxygen uptake, and in some cardiovascular parameters following rehabilitation. Leg fatigue was also significantly reduced, supporting the reported positive effect of physical exercise on muscle function. The novel aspect of the study is to compare cardiopulmonary exercise variables at ‘submaximal’ exercise levels, isometabolic and isoventilatory levels (‘isolevels’) before and after rehabilitation. Of note, the O 2 pulse (peak oxygen uptake/heart rate) and tidal volume were significantly higher after rehabilitation. Furthermore, tidal volume changes correlated significantly with changes in O 2 pulse. The authors concluded that the most likely explanation for their observations was an improvement in cardiovascular function due to a reduction It has been estimated that physical inactivity is worldwide responsible for 6–10% of the major non-communicable diseases. Furthermore, sedentary lifestyle causes 9% of premature mortality [1] . Moreover, recent studies have consistently shown that messages emphasizing the benefits of being active are more effective at changing physical activity behaviour than those stressing the consequences of inactivity [2] . Chronic obstructive pulmonary disease (COPD) is a complex disease mainly characterized by structural abnormalities of the airways and lungs, but it is very often associated with concomitant comorbidities. The presence of comorbidities strongly influences not only the severity of symptoms, but also the risk of hospitalization and death [3] . The relationship between COPD and cardiovascular disease is particularly notable and of clinical relevance, as cardiovascular disease represents the most common comorbidity and the leading cause of hospitalization in patients with mild-to-moderate COPD [4] . Exercise-based pulmonary rehabilitation is a well-established intervention for patients with COPD. Physical training, by improving skeletal muscle function, positively influences exercise tolerance and symptoms; this is mainly due to a reduction in lung dynamic hyperinflation but also to a desensitization to central dyspnea [5] . There is now emerging evidence to support the efficacy of exercise-based pulmonary rehabilitation also in the management of COPD exacerbations. An up-to-date Cochrane meta-analysis shows that pulmonary rehabilitation sigPublished online: May 30, 2013
2,611 citations
TL;DR: The role of dynamic hyperinflation in exercise limitation in chronic obstructive pulmonary disease (COPD) remains to be defined and the extent of DH during exercise in COPD correlated best with resting IC.
Abstract: The role of dynamic hyperinflation (DH) in exercise limitation in chronic obstructive pulmonary disease (COPD) remains to be de- fined. We examined DH during exercise in 105 patients with COPD (FEV 1 � 37 � 13% predicted; meanSD) and studied the rela- tionships between resting lung volumes, DH during exercise, and peak oxygen consumption ( O 2 ). Patients completed pulmonary function tests and incremental cycle exercise tests. We measured the change in inspiratory capacity ( ∆ IC) during exercise to reflect changes in DH. During exercise, 80% of patients showed signifi- cant DH above resting values. IC decreased 0.37 � 0.39 L or 14 � 15% predicted during exercise (p � 0.0005), but with large varia- tion in range. ∆ IC correlated best with resting IC, both expressed %predicted (r � � 0.50, p � 0.0005). Peak O 2 (%predicted maxi- mum) correlated best with the peak tidal volume attained (V T standardized as % of predicted vital capacity) (r � 0.68, p � 0.0005), which, in turn, correlated strongly with IC at peak exer- cise (r � 0.79, p � 0.0005) or at rest (r � 0.75, p � 0.0005). The extent of DH during exercise in COPD correlated best with resting IC. DH curtailed the V T response to exercise. This inability to ex- pand V T in response to increasing metabolic demand contributed importantly to exercise intolerance in COPD. Chronic obstructive pulmonary disease (COPD) is a heteroge- neous disorder characterized by dysfunction of the small and large airways, as well as destruction of the lung parenchyma and its vasculature in highly variable combinations. The pathophysiological hallmark of COPD is expiratory flow limi- tation, which, in more advanced disease, occurs even during resting quiet breathing. As a consequence, resting lung vol- ume (functional residual capacity (FRC)) is dynamically, and not statically, determined. During exercise, as ventilatory de- mands increase in flow-limited patients, progressive air trap- ping and further dynamic lung hyperinflation (DH) above al- ready increased resting values is inevitable (1, 2). Recent studies have shown that DH during exercise contributes to perceived respiratory discomfort (3, 4). Indirect evidence of the importance of DH comes from studies that have demon- strated that alleviation of dyspnea following bronchodilator therapy and lung volume reduction surgery (LVRS) was ex- plained, in part, by reduced operating lung volumes (5, 6). However, it is not clear from previous studies to what extent the behavior of operating lung volumes during exercise influ- ences peak exercise capacity in COPD. Moreover, earlier studies have shown wide variability in the extent of DH with V ·
1,124 citations
TL;DR: Results show that the use of tiotropium was associated with sustained reductions of lung hyperinflation at rest and during exercise and contributed to improvements in both exertional dyspnoea and exercise endurance.
Abstract: The aim of this study was to test the hypothesis that use of tiotropium, a new long-acting anticholinergic bronchodilator, would be associated with sustained reduction in lung hyperinflation and, thereby, would improve exertional dyspnoea and exercise performance in patients with chronic obstructive pulmonary disease. A randomised, double-blind, placebo-controlled, parallel-group study was conducted in 187 patients (forced expiratory volume in one second 44 +/- 13% pred): 96 patients received 18 microg tiotropium and 91 patients received placebo once daily for 42 days. Spirometry, plethysmographic lung volumes, cycle exercise endurance and exertional dyspnoea intensity at 75% of each patient's maximal work capacity were compared. On day 42, the use of tiotropium was associated with the following effects at pre-dose and post-dose measurements as compared to placebo: vital capacity and inspiratory capacity (IC) increased, with inverse decreases in residual volume and functional residual capacity. Tiotropium increased post-dose exercise endurance time by 105 +/- 40 s (21%) as compared to placebo on day 42. At a standardised time near end-exercise (isotime), IC, tidal volume and minute ventilation all increased, whilst dyspnoea decreased by 0.9 +/- 0.3 Borg scale units. In conclusion, the use of tiotropium was associated with sustained reductions of lung hyperinflation at rest and during exercise. Resultant increases in inspiratory capacity permitted greater expansion of tidal volume and contributed to improvements in both exertional dyspnoea and exercise endurance.
921 citations
TL;DR: This review will focus on the potential role of plotting the extFVL within the MFVL for determination of ventilatory constraint during exercise in the clinical setting and important physiologic concepts, measurements, and limitations obtained will be defined and discussed.
361 citations
TL;DR: Within-breath respiratory system reactance provides an accurate, reliable and noninvasive technique to detect expiratory flow limitation in patients with chronic obstructive pulmonary disease.
Abstract: Expiratory flow limitation (EFL) during tidal breathing is a major determinant of dynamic hyperinflation and exercise limitation in chronic obstructive pulmonary disease (COPD). Current methods of detecting this are either invasive or unsuited to following changes breath-by-breath. It was hypothesised that tidal flow limitation would substantially reduce the total respiratory system reactance (Xrs) during expiration, and that this reduction could be used to reliably detect if EFL was present. To test this, 5-Hz forced oscillations were applied at the mouth in seven healthy subjects and 15 COPD patients (mean +/- sD forced expiratory volume in one second was 36.8 +/- 11.5% predicted) during quiet breathing. COPD breaths were analysed (n=206) and classified as flow-limited if flow decreased as alveolar pressure increased, indeterminate if flow decreased at constant alveolar pressure, or nonflow-limited. Of these, 85 breaths were flow-limited, 80 were not and 41 were indeterminate. Among other indices, mean inspiratory minus mean expiratory Xrs (deltaXrs) and minimum expiratory Xrs (Xexp,min) identified flow-limited breaths with 100% specificity and sensitivity using a threshold between 2.53-3.12 cmH2O x s x L(-1) (deltaXrs) and -7.38- -6.76 cmH2O x s x L(-1) (Xexp,min) representing 6.0% and 3.9% of the total range of values respectively. No flow-limited breaths were seen in the normal subjects by either method. Within-breath respiratory system reactance provides an accurate, reliable and noninvasive technique to detect expiratory flow limitation in patients with chronic obstructive pulmonary disease.
348 citations
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| Year | Papers |
|---|---|
| 2025 | 11 |
| 2024 | 19 |
| 2023 | 23 |
| 2022 | 35 |
| 2021 | 29 |
| 2020 | 22 |