EMC - Pneumologie最新文献

Sarcoidosis is a multisystemic granulomatous disease of unknown cause, which most frequently involves the lung and the lymphatic system. It is generally observed between 25 and 45 years old. Various clinical phenotypes exist, depending on involved organs, duration and severity. Chest radiography is abnormal in 86-92% of the cases. Four different radiographic stages have been defined, based on the presence or absence of hilar lymphadenopathy and/or lung infiltration with or without fibrosis, each determining a different prognosis. The evolution is favourable in 12-36 months in 50% of patients but the course of the disease can be severe when granulomatous lesions are localized in some particular sites or in case of pulmonary fibrosis. The diagnosis is established on the combination of clinical and radiological presentation, histopathological findings and the exclusion of other granulomatous disorders. Sarcoidosis is characterized by an uncontrolled immunological reaction to unidentified antigens with a low clearance. The formation of the granulomas is controlled by a Th1 type response. The incidence and the clinical phenotype of the disease depend on predisposing genetic factors. Even in the absence of evident cause, several medications including glucocorticoid agents have demonstrated efficacy on granulomatous lesions. Their effect is only suspensive. They are indicated only when a beneficial effect is expected and they must be given for at least one year.

Pharyngo-oesophageal diverticulum, also called Zenker's diverticulum, is the most frequent of the oesophageal diverticula. It is a hernia of the pharyngeal mucosa through the muscular layer of the pharyngo-oesophageal junction. It results from a defect in the opening of the cricopharyngeus muscle. The most common symptoms are dysphagia, regurgitations and less often pulmonary manifestations such as cough and pulmonary infections. Barium swallow helps to establish the diagnosis. The treatment is either surgical consisting of a diverticulectomy with a myotomy of the cricopharyngeus muscle, or it is endoscopic, consisting in stappled diverticulostomy. Diverticula of the mid and low oesophagus are hernias of oesophageal mucosa through the muscular layer of the oesophagus resulting from underlying motility disorders. Most of them give few or no symptoms. Existing symptoms are dysphagia, regurgitations, pulmonary manifestations or pyrosis. Barium swallow is used for establishing the diagnosis. Treatment is surgical. It is associated with a high rate of morbidity and post operative mortality, with an uncertain functional result. Consequently such diverticula should be surgically treated only if very symptomatic. Usual approach consists of diverticulectomy with myotomy of the lower oesophagus. No study has evidenced the best surgical approach yet. In the future, “mini-invasive” techniques could become the reference technique for treatment of epiphrenic diverticula.

Mediastinal tumours of embryonic origin refer to tumours resulting from a disorder of the embryonic development, or to tumours deriving from germinal cells and of which the primitive localization is the mediastinum. Such tumours are constituted by tissues similar to those that successively develop from the embryonic to the adult stage. These benign or malignant lesions are classified according to their histogenesis and the available therapeutic means. Germinal tumours are constituted by tissues similar to those that succeed one another during the development, by differentiation of primitive laminas and extraembryonic laminas. In terms of therapy, seminomas have to be distinguished from non seminomatous germinal tumours, and from teratomas. Mediastinal cysts are malformations constituted by tissues included normally into the adult thorax. They are distributed in five classes, according to their structure: bronchogenic and paraoesophageal cysts, pleuropericardic cysts, cystic lymphangiomas, benign haemangiomas, and meningeal cysts.

Reviewing respiration pathophysiology allows understanding how a patient affected by a neuromuscular disease may present respiratory symptoms and which treatment can be effective. Affection of inspiration muscles, especially the diaphragm, generates a restrictive syndrome and early sleep disorders. Precise and simple investigations allow evaluating the extent of respiratory involvement and the indication for ventilatory support. The impairment of expiratory muscles has consequences, often neglected, such as impaired cough capacity and speech. Again, evaluation is useful in determining which treatment can be initiated. Finally, swallowing impairment should not be underestimated as it may compromise pulmonary function. Likewise, a thromboembolic disease does not be underestimated in patients with multiple risk factors. We exhaustively reviewed the different tools available for evaluation and treatment of the respiratory consequences of neuromuscular diseases. Their use should be considered for every patient presenting with a neuromuscular disease; multidisciplinary management should be implemented, involving a pneumologist.

The goal of investigating lung function is to evaluate the severity of a pathological functional impairment of the respiratory system, to elucidate its underlying mechanism, to help for the differential diagnosis and to check therapeutic effects. All these points may be solved by measuring lung volumes, airways permeability and diffusion of gases between air and blood. These tests can show too small (restriction) or too large (distension) lung volumes, bridled air flow through the airways (obstruction) or impaired transfer of gases to the blood (emphysema, fibrosis). They also measure the reversibility of airway obstruction using a bronchodilator, and conversely they may assess bronchi hyper-reactivity to an inhaled irritant substance. The severity of the functional impairment, as well as the recovery of normal function after therapy can be evaluated using tabulated predicted normal values. More sophisticated tests are used to assess decreased strength of the respiratory muscles, ventilatory response to hypercapnia or respiratory behaviour during exercise, especially when basic tests failed to explain the symptoms or the functional impairment. In case of severe respiratory insufficiency, blood gases (O₂, CO₂) measurements and acid-base equilibrium (pH) are often the only practicable tests.