Qualitative aspects of exertional breathlessness in chronic airflow limitation: pathophysiologic mechanisms.

O’Donnell, Denis E.; Bertley, John C.; Chau, Laurence.K.L.; Webb, Katherine A.

doi:10.1164/ajrccm.155.1.9001298

Cited by 385 publications

(357 citation statements)

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“…It has previously been reported that, in contrast to health, the most commonly selected dyspnoea descriptors during exercise in COPD are unsatisfied inspiration ("I can9t get enough air in") and inspiratory difficulty [7]. At peak exercise under the two conditions, dyspnoea intensity was similar, but patients selected the descriptor "unsatisfied inspiration" less frequently (reduced by 22%) after salmeterol.…”

Section: Effect On Dyspnoeamentioning

confidence: 86%

“…At rest, every 2 min during exercise and at end-exercise, subjects rated the intensity of their breathing and leg discomfort using the modified Borg scale [18] and performed IC manoeuvres [6,19]. At the end of exercise, subjects specified their reason for stopping exercise and completed a questionnaire describing the quality of their exertional dyspnoea [7,20]. Predicted maximum values for work-rate, cardiac frequency and V9O 2 were taken from JONES [21].…”

Section: Methodsmentioning

confidence: 99%

“…This phenomenon has been termed neuromechanical dissociation. The ratio of inspiratory effort (tidal oesophageal pressure relative to maximum) to VT displacement is increased during exercise in COPD compared with health, and correlates well with intensity of inspiratory difficulty [7]. Similarly, in health, when VT is constrained by chest wall strapping during exercise, dyspnoea also intensifies [8].…”

mentioning

confidence: 91%

“…Thus, in hyperinflated COPD patients, close intercorrelations were found between the reduced resting IC, reduced peak VT and reduced symptom-limited peak oxygen uptake (V9O 2 ) [6]. It was reasoned that bronchodilator-induced increases in resting IC should result in greater VT expansion throughout exercise, with greater ventilatory capacity and improved exercise ability.Similarly, it was previously hypothesised that the inability to expand VT appropriately in response to the increasing central drive of exercise can contribute to both the intensity and quality (unsatisfied inspiration) of exertional dyspnoea [7,8]. During exercise, inspiratory effort and central drive increase progressively in the face of increasingly restricted VT expansion in COPD.…”

mentioning

confidence: 93%

“…Similarly, it was previously hypothesised that the inability to expand VT appropriately in response to the increasing central drive of exercise can contribute to both the intensity and quality (unsatisfied inspiration) of exertional dyspnoea [7,8]. During exercise, inspiratory effort and central drive increase progressively in the face of increasingly restricted VT expansion in COPD.…”

mentioning

confidence: 93%

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Effect of salmeterol on the ventilatory response to exercise in chronic obstructive pulmonary disease

O’Donnell¹,

Voduc²,

Fitzpatrick³

et al. 2004

Eur Respir J

331

273

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This study examined the effects of bronchodilator-induced reductions in lung hyperinflation on breathing pattern, ventilation and dyspnoea during exercise in chronic obstructive pulmonary disease (COPD). Quantitative tidal flow/volume loop analysis was used to evaluate abnormalities in dynamic ventilatory mechanics and their manipulation by a bronchodilator.In a randomised double-blind crossover study, 23 patients with COPD (mean¡SEM forced expiratory volume in one second 42¡3% of the predicted value) inhaled salmeterol 50 mg or placebo twice daily for 2 weeks each. After each treatment period, 2 h after dose, patients performed pulmonary function tests and symptom-limited cycle exercise at 75% of their maximal work-rate.After salmeterol versus placebo at rest, volume-corrected maximal expiratory flow rates increased by 175¡52%, inspiratory capacity (IC) increased by 11¡2% pred and functional residual capacity decreased by 11¡3% pred. At a standardised time during exercise, salmeterol increased IC, tidal volume (VT), mean inspiratory and expiratory flows, ventilation, oxygen uptake (V9O 2 ) and carbon dioxide output. Salmeterol increased peak exercise endurance, V9O 2 and ventilation by 58¡19, 8¡3 and 12¡3%, respectively. Improvements in peak V9O 2 correlated best with increases in peak VT; increases in peak VT and resting IC were interrelated. The reduction in dyspnoea ratings at a standardised time correlated with the increased VT.Mechanical factors play an important role in shaping the ventilatory response to exercise in chronic obstructive pulmonary disease. Bronchodilator-induced lung deflation reduced mechanical restriction, increased ventilatory capacity and decreased respiratory discomfort, thereby increasing exercise endurance. Several recent studies have shown that improvements in exertional dyspnoea following bronchodilator therapy in chronic obstructive pulmonary disease (COPD) correlate well with reductions in lung hyperinflation, as indicated by increases in inspiratory capacity (IC) [1][2][3][4][5]. However, the relationship between bronchodilator-induced increases in IC and improvements in symptoms and exercise performance is complex and poorly understood. Given the multifactorial nature of dyspnoea and exercise limitation in COPD, it remains unclear why small increases in resting IC (in the order of 0.3 L) appear to be clinically important. The current study extends previous studies conducted in the present authors9 laboratory using ipratropium bromide by, in addition, examining the effect of a bronchodilator (salmeterol) on plethysmographic lung volume components at rest and on breathing pattern and ventilatory capacity during exercise. Moreover, the study was designed to advance understanding of the mechanisms of bronchodilatorinduced dyspnoea relief, especially the role of reduced mechanical restriction.It has previously been shown that acute-on-chronic hyperinflation during exercise severely constrains tidal volume (VT) expansion, and that this dynamic mechanical restriction makes ...

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Section: Effect On Dyspnoeamentioning

confidence: 86%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 91%

mentioning

confidence: 93%

mentioning

confidence: 93%

See 3 more Smart Citations

Effect of salmeterol on the ventilatory response to exercise in chronic obstructive pulmonary disease

O’Donnell¹,

Voduc²,

Fitzpatrick³

et al. 2004

Eur Respir J

331

273

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Management of Dyspnea in Patients With Far-Advanced Lung Disease

Luce

Luce²

2001

JAMA

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Dyspnea is a common problem among patients with interstitial fibrosis, lung cancer, cystic fibrosis, and chronic obstructive pulmonary disease. The slow but steady progression of such diseases, often punctuated by acute exacerbations or secondary illnesses, can lead to decision-making dilemmas among patients and their caregivers, such as when to accept mechanical ventilation, when to forgoe aggressive therapies, and when to make formal end-of-life care plans. Two cases, a 74-year-old woman with dyspnea secondary to emphysema and a 65-year-old woman with recurrent lung cancer and severe exertional fatigue and dyspnea, illustrate how dyspneic patients approaching the end of life can be evaluated and treated. Four management strategies for dyspnea are discussed: reducing ventilatory impedance, reducing ventilatory demand, improving respiratory muscle function, and altering central perception. Physicians should encourage end-stage lung disease patients and their families to discuss issues such as hospitalization and mechanical ventilation, to prepare advance directives, and to participate in a plan to manage their dyspnea.

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Management of Dyspnea in Patients With Far-Advanced Lung Disease

Markowitz¹

2002

JAMA

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EVERE DYSPNEA IS COMMON AMONG PATIENTS WITH end-stage lung disease but is disabling and challenging to treat. Using interviews with 2 patients with severe dyspnea, one with end-stage chronic obstructive pulmonary disease and the other with lung cancer, Drs Luce and Luce discuss approaches to helping alleviate dyspnea for patients nearing the end of life, and maximizing comfort and function for the patients' remaining time. THE PATIENTS' STORIESMrs D is a 74-year-old woman, followed up for the past 4 years for management of dyspnea secondary to emphysema. Her pulmonologist, Dr M, relates that she has had a substantial active (25 pack-years) and passive (husband smoked 2 packs per day) tobacco exposure. She is thin, with pursed-lip breathing and sternocleidomastoid contractions. Pulmonary function tests demonstrate severe airflow obstruction, air trapping, and marked reduction in diffusing capacity.Portable oxygen allows her to continue activities outside of the home, including shopping, visiting family, and attending professional football games-her passion. On supplementary oxygen (4 L /min) her symptoms have improved, with increased exercise tolerance and resolution of pedal edema. She uses a variable regimen of inhaled ipratropium bromide, albuterol, and fluticasone propionate, in addition to oral prednisone.Mrs I is a 65-year-old woman diagnosed with limitedstage small-cell lung cancer in 1995. She was treated with chemotherapy (cisplatin and etoposide) and radiation, with substantial decrease in the size of the tumor. She is now cared for by Dr K, a pulmonary oncologist. In December 1999, she experienced a central nervous system (CNS) recurrence of her cancer and was treated with radiation and corticosteroids. Though her neurologic symptoms improved, she became extremely fatigued and dyspneic upon exertion. Simple activities of daily living are quite difficult, in part due to her shortness of breath, and she has opted to forgo further antineoplastic therapy in favor of home hospice care. PERSPECTIVESMrs D and Mrs I, as well as their physicians and family members, were interviewed in June 2000 by Perspectives editors. MRS D: It's kind of hard to get your breath back. If you're riding a horse or you're swimming you can get the breath in and out fast enough. But with shortness of breath, coming out takes longer. It's the only way I can explain it . . . Once I lose it, it's kind of hard to catch it. That's what scares me.DR M (Mrs D's pulmonologist): Probably the hardest thing pulmonologists do is help patients prepare for the end of life, particularly patients with chronic obstructive pulmonary disease, as this preterminal period can be so prolonged. While it's important to address end-of-life care early, I am concerned that Dyspnea is a common problem among patients with interstitial fibrosis, lung cancer, cystic fibrosis, and chronic obstructive pulmonary disease. The slow but steady progression of such diseases, often punctuated by acute exacerbations or secondary illnesses, can lead to decisionmaking dilemmas...

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Qualitative aspects of exertional breathlessness in chronic airflow limitation: pathophysiologic mechanisms.

Cited by 385 publications

References 21 publications

Effect of salmeterol on the ventilatory response to exercise in chronic obstructive pulmonary disease

Effect of salmeterol on the ventilatory response to exercise in chronic obstructive pulmonary disease

Management of Dyspnea in Patients With Far-Advanced Lung Disease

Management of Dyspnea in Patients With Far-Advanced Lung Disease

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