Restrictive lung diseases are a heterogeneous set of pulmonary disorders defined by restrictive patterns on spirometry. These disorders are characterized by a reduced distensibility of the lungs, compromising lung expansion, and, in turn, reduced lung volumes, particularly with reduced total lung capacity (TLC).[1] These functional and other characteristics allow to differentiate them from obstructive pulmonary diseases such as chronic obstructive pulmonary disease (COPD), bronchiectasis, asthma, emphysema, and bronchiolitis characterized by increased resistance to flow due to obstruction partial or complete at any level, from the trachea to the terminal bronchioles. In numerical terms, restrictive syndromes account for about a fifth of pulmonary syndromes, while obstructive syndromes are the majority (80%).[2]
Restrictive lung diseases may be caused by the destruction of distal lung parenchyma due to infiltrates from inflammation, toxins, and mechanisms yet to be elucidated (intrinsic conditions) as well as extra parenchymal conditions (extrinsic causes). Within the former group, there are diseases characterized by inflammatory changes involving the alveolar interstitium with possible involvement of the peripheral bronchial structures. The conditions leading to this destruction are encompassed among the interstitial lung diseases (ILDs). This term refers to an umbrella with numerous disorders that are characterized by diffuse cellular infiltrates in a periacinar location, including clinical conditions that vary from occasional self-limited inflammatory processes to severe debilitating fibrosis of the lungs. Other conditions originate from within the alveolus (e.g., edema, hemorrhage) and spread to interstitial structures. If the process starts from the interstitium or from the alveolus, in both cases, alteration of the lung architecture, which reverberates into functional impairment occurs.
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On the other hand, restrictive lung diseases may also result from limitations in neuromuscular function and chest wall movements (extrinsic causes). These may be due to neuromuscular diseases, pleural disorders, obesity, costosternal or costovertebral fusion, a fusion or deviation of the thoracic vertebra, and other etiologies that result in a physical impediment to inspiration.[3] Regardless of the intrinsic or extrinsic mechanisms, these diseases are featured by impaired ventilatory function and respiratory failure.
Intrinsic, or pulmonary causes, involve the lung parenchyma itself, while the extrinsic restrictive lung diseases originate from neuromuscular disorders, obesity, and other extra-parenchymal disorders.[1] In both intrinsic or extrinsic pulmonary conditions, lung volumes become reduced due to restrictions in pulmonary mechanics.
Extrapulmonary diseases can also be schematically grouped into pathologies that produce a decreased muscle tone of the respiratory pump (e.g., myopathies, and neurological deficits), deformations of the rib cage (e.g., kyphoscoliosis), and space occupation (e.g., pleural effusions, pneumothorax).
Of note, in restrictive diseases, the forced expiratory volume over 1 second (FEV1) usually slightly decreases or stays normal, and the ratio of FEV1 to FVC is generally preserved or increased. These alterations in pulmonary dynamics can be compensated by an increased respiratory rate, with hypercapnia developing only at later stages of the disease.[16]
It has histological and radiological characteristics different from all the other interstitial diseases of unknown etiology. It is essential to know its morphologic and clinic features as, compared to IPF, this disease manifests a much better prognosis. Morphologically, there are changes in lung architecture that do not fully meet the criteria which underlie the other forms of pulmonary interstitial disease. Three subgroups of the NSIP pattern can be recognized:
It is a multisystemic inflammatory disease that begins more frequently between 20 and 40 years of age and represents the most frequent of all interstitial lung diseases. The lungs are almost constantly affected (about 90% of cases) with bilateral pulmonary hilar lymph node involvement and possible simultaneous involvement of the lungs. Histopathology features include noncaseating epithelioid granulomas with tightly packed epithelioid cells, Langhans giant cells, and T lymphocytes. These findings are localized in interstitium adjacent to bronchioles as well as around and within vessel walls, pleura, and connective tissue septa. There are Schaumann bodies (laminated concretions of calcium and protein) and asteroid elements (stellate inclusions within giant cells).
The differential diagnosis of pulmonary restriction remains broad even after it has been diagnosed by PFTs as there are several causes of pulmonary restriction. Intrinsic pulmonary restriction can be caused by any of the interstitial lung diseases such as
Advanced restrictive lung disease results in hypoxemia, which can only be compensated by elevations in respiratory rate. Increased energy expenditure in breathing can lead to muscle wasting and weight loss. Once compensatory mechanisms fail, and hypoxia worsens, patients develop chronic respiratory failure. Sleep disorders, including obstructive sleep apnea (OSA), which are common in patients with extrinsic pulmonary restriction due to obesity, have also been noted in a significant amount of patients with intrinsic restrictive lung disease.[30] Chronic respiratory failure and lung architecture distortion lead to pulmonary hypertension and cor-pulmonale.
INTRODUCTION: Physical therapy is involved in the non-medical treatment of patients with acute and chronic respiratory diseases, including obstructive and restrictive pulmonary diseases, patients with neuromuscular disorders, patients admitted for major surgery and patients with critical illness in intensive care. Physical therapy contributes towards assessing and treating various aspects of respiratory disorders such as airflow obstruction, mucus retention, alterations in ventilatory pump function, dyspnea, impaired exercise performance and quality of life. CONCLUSION: Exercise training, peripheral and respiratory muscle training, airway clearance techniques and lung expansion in spontaneous breathing patients (lung expansion maneuvers, huffing and assisted coughing) and in mechanically ventilated patients (bagsqueezing), and breathing retraining (pursed lips breathing, active expiration) have been shown effective in selected patients with disorders affecting the respiratory system. Assessment of patients is critical to identify patient characteristics that allow appropriate selection of treatment modalities providing optimal effectiveness and efficacy.
INTRODUCTION: Physical therapy is involved in the non-medical treatment of patients with acute and chronic respiratory diseases, including obstructive and restrictive pulmonary diseases, patients with neuromuscular disorders, patients admitted for major surgery and patients with critical illness in intensive care. Physical therapy contributes towards assessing and treating various aspects of respiratory disorders such as airflow obstruction, mucus retention, alterations in ventilatory pump function, dyspnea, impaired exercise performance and quality of life.
In quadriplegic patients, respiratory muscle training has also been shown to enhance inspiratory muscle function, pulmonary function and dyspnea39,40, but a recent systematic review could not confirm this41. In patients with neuromuscular disease (NMD), respiratory muscle dysfunction is more complex and dependent on the precise disease and its stage. It seems that NMD patients for whom more than 25% of the predicted pulmonary function still remains are still trainable42. Although inspiratory muscle function is commonly affected in these diseases, expiratory muscle function is often more impaired in quadriplegia and multiple sclerosis. Expiratory muscle training has also been shown to be beneficial in the latter condition43. Over the long term, the progressive nature of most neuromuscular diseases affecting the primary function of the muscle probably impedes the beneficial effects of training.
Hypersecretion and impaired mucociliary transport are important pathophysiological features of obstructive lung diseases like cystic fibrosis and chronic bronchitis, as well as in patients with acute lung disease, i.e. atelectasis and pneumonia. Hypersecretion is associated with an increased rate of decline of pulmonary function and excess mortality in patients with COPD57. In patients with more advanced neuromuscular disease, mucus retention and pulmonary complications significantly contribute towards morbidity and mortality58. Although a cause-effect relationship has not been proven under these conditions, improvement of airway clearance is considered to be an important aim in treating such patients. 2ff7e9595c
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