Pulmonary Function in Progressive Muscular Dystrophy

Hapke, Edith J.; Meek, Joseph C.; Jacobs, Joannes F M

doi:10.1378/chest.61.1.41

Cited by 60 publications

(33 citation statements)

References 5 publications

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“…The reduced vital capacities of our pa tients support the findings of others re garding restrictive impairment [3,4,7]. None of our patients were hypoventilating.…”

Section: Pulmonary Function Abnormalitiessupporting

confidence: 89%

“…Most of the reported data are interpreted as consequences of an insufficient cough ing function due to muscular weakness and restrictive impairment with no indica tion of obstructive elements [1][2][3][4]. Con tradictory ventilatory responses to CO2 have been reported [5,6], The type of re striction is not fully clarified although a reduction in total lung capacity and an in crease in residual volume associated with a loss in muscle strength has been found [6] but with no increase in airway resist ance (Raw).…”

Section: Introductionmentioning

confidence: 99%

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Cardiopulmonary Response to Exercise in Patients with Neuromuscular Diseases

Lyager¹,

Noeraa²,

Pedersen³

1984

Respiration

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In order to evaluate the possible effects of respiratory muscle training in patients with neuromuscular disease, we examined the cardiopulmonary response in 13 patients and 17 healthy controls by recording flow volume curves, ECG and alveolar carbon dioxide levels and collecting mixed expiratory air in Douglas bags. The cardiopulmonary response of our patients was not significantly different from that of the controls, and therefore we see no reason to avoid muscle training in patients with such disease.

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“…The reduced vital capacities of our pa tients support the findings of others re garding restrictive impairment [3,4,7]. None of our patients were hypoventilating.…”

Section: Pulmonary Function Abnormalitiessupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Cardiopulmonary Response to Exercise in Patients with Neuromuscular Diseases

Lyager¹,

Noeraa²,

Pedersen³

1984

Respiration

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“…It is well established that weakness of the respiratory muscles causes a restrictive ventilatory defect with a reduction in TLC. However, the resting end expiratory position (FRC) in patients with respiratory muscle weakness can be decreased [19,[25][26][27], normal [28,29] or increased [30], while RV can be normal [19,27] or increased [22,[28][29][30]. To examine whether these differences could be due to differences in the distribution of respiratory muscle weakness, the current authors analysed values of FRC and RV in eight studies [2,19,22,[30][31][32][33][34] that have reported both lung volumes and inspiratory and/or expiratory muscle function.…”

Section: Significance Of the Findingsmentioning

confidence: 99%

Effect of pattern and severity of respiratory muscle weakness on carbon monoxide gas transfer and lung volumes

Hart¹,

Cramer²,

Ward³

et al. 2002

Eur Respir J

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In clinical practice, an elevated carbon monoxide (CO) transfer coefficient (KCO) and restrictive ventilatory defect are taken as features of respiratory muscle weakness (RMW). However, the authors hypothesised that both pattern and severity of RMW effect gas transfer and lung volumes.Measurements of CO transfer and lung volumes were performed in patients with isolated diaphragm weakness (n=10), inspiratory muscle weakness (n=12), combined inspiratory and expiratory muscle weakness (n=5) and healthy controls (n=6).Patients with diaphragm weakness and inspiratory muscle weakness had reduced total lung capacity (TLC) (83.6% predicted and 68.9% pred, respectively), functional residual capacity (FRC) (83.9% pred and 83.6% pred) and transfer factor of the lung for CO (TL,CO) (86.2% pred and 66.2% pred) with increased KCO (114.1% pred and 130.2% pred). Patients with combined inspiratory and expiratory muscle weakness had reduced TLC (80.9% pred) but increased FRC (109.9% pred) and RV (157.4% pred) with decreased TL,CO (58.0% pred) and KCO (85.5% pred).In patients with diaphragm weakness, the increase in carbon monoxide transfer coefficient was similar to that of normal subjects when alveolar volume was reduced. However, the increase in carbon monoxide transfer coefficient in inspiratory muscle weakness was often less than expected, while in combined inspiratory and expiratory muscle weakness, the carbon monoxide transfer coefficient was normal/reduced despite further reductions in alveolar volume, which may indicate subtle abnormalities of the lung parenchyma or pulmonary vasculature. Thus, this study demonstrates the limitations of using carbon monoxide transfer coefficient in the diagnosis of respiratory muscle weakness, particularly if no account is taken of the alveolar volume at which the carbon monoxide transfer coefficient is made. Transfer factor of the lung for carbon monoxide (CO) (TL,CO) is the product of the CO transfer coefficient (KCO), which indicates the rate constant of CO uptake from the alveoli and the alveolar volume (VA) at which the measurement is made [1]. Many studies, including the original study by KROGH [1], have shown that if CO transfer is measured at submaximal VA, the decline in TL,CO is partially offset by an increase in KCO. In clinical practice, CO uptake is measured at total lung capacity (TLC), but many disease states associated with a reduced TLC often have coexistent intrapulmonary disease and, as a consequence, have a reduction in KCO. However, when the cause of the reduced TLC is extrapulmonary, a distinctive pattern may be found in which KCO is increased at full inflation and VA is decreased, so that reductions in TL,CO are smaller than observed in intrapulmonary disease. The most obvious disorder simulating the effects of submaximal inflation is inspiratory muscle weakness without intrapulmonary disease. In an influential study of six patients [2], in which TLC was reduced due to severe isolated diaphragm weakness, a relatively benign disease in the absence of other...

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“…8 Although these instruments were designed to evaluate functional impairment caused by peripheral muscle dysfunction, a correlation between worse functional classes and reduced forced vital capacity (FVC) and total lung capacity has been suggested. [9][10][11] More recently, an additional instrument was developed to evaluate the functional status of patients with advanced DMD and spinal muscular atrophy. 12,13 The Egen Klassifikation (EK) scale (Egen Klassifikation translation from Danish: "our own classification") was designed to reflect the progressive loss of physical ability for 10 main tasks: (1) control an electric chair, (2) transfer from the wheelchair, (3) stand, (4) sit up, (5) use the arms, (6) use the arms for eating, (7) turn in bed, (8) cough, (9) talk, and (10) general well-being.…”

mentioning

confidence: 99%