Pulmonary Disorders

Key components in the evaluation of patients with pulmonary symptoms are the history, physical examination, and, in most cases, a chest x-ray. These components establish the need for subsequent testing, which may include pulmonary function testing and arterial blood gas (ABG) analysis, computed tomography (CT) or other chest imaging tests, and bronchoscopy.

Bronchoscopy is the introduction of an endoscope into the airways.

Needle thoracostomy is insertion of a needle into the pleural space to decompress a tension pneumothorax.

Pulmonary function tests provide measures of airflow, lung volumes, gas exchange, response to bronchodilators, and respiratory muscle function.

Acute bronchitis is inflammation of the tracheobronchial tree, commonly following a URI, that occurs in patients without chronic lung disorders. The cause is almost always a viral infection. The pathogen is rarely identified. The most common symptom is cough, with or without fever, and possibly sputum production. Diagnosis is based on clinical findings. Treatment is supportive; antibiotics are usually unnecessary. Prognosis is excellent.

Bronchiectasis is dilation and destruction of larger bronchi caused by chronic infection and inflammation. Common causes are cystic fibrosis, immune defects, and recurrent infections, though some cases seem to be idiopathic. Symptoms are chronic cough and purulent sputum expectoration; some patients may also have fever and dyspnea. Diagnosis is based on history and imaging, usually involving high-resolution computed tomography, though standard chest x-rays may be diagnostic. Treatment and prevention of acute exacerbations are with bronchodilators, clearance of secretions, antibiotics, and management of complications, such as hemoptysis and further lung damage due to resistant or opportunistic infections. Treatment of underlying disorders is important whenever possible.

Chronic obstructive pulmonary disease (COPD) is airflow limitation caused by an inflammatory response to inhaled toxins, often cigarette smoke. Alpha-1 antitrypsin deficiency and various occupational exposures are less common causes in nonsmokers. Symptoms are productive cough and dyspnea that develop over years; common signs include decreased breath sounds, prolonged expiratory phase of respiration, and wheezing. Severe cases may be complicated by weight loss, pneumothorax, frequent acute decompensation episodes, right heart failure, and/or acute or chronic respiratory failure. Diagnosis is based on history, physical examination, chest x-ray, and pulmonary function tests. Treatment is with bronchodilators, corticosteroids, and, when necessary, oxygen and antibiotics. About 50% of patients with severe COPD die within 10 yr of diagnosis.

Diffuse alveolar hemorrhage is persistent or recurrent pulmonary hemorrhage. There are numerous causes, but autoimmune disorders are most common. Most patients present with dyspnea, cough, hemoptysis, and new alveolar infiltrates on chest imaging. Diagnostic tests are directed at the suspected cause. Treatment is with immunosuppressants for patients with autoimmune causes and respiratory support if needed.

Environmental pulmonary diseases result from inhalation of dusts, allergens, chemicals, gases, or environmental pollutants. The lungs are continually exposed to the external environment and are susceptible to a host of environmental challenges. Pathologic processes can involve any part of the lungs, including the

Interstitial lung diseases are a heterogeneous group of disorders characterized by alveolar septal thickening, fibroblast proliferation, collagen deposition, and, if the process remains unchecked, pulmonary fibrosis. Interstitial lung diseases can be classified using various criteria (eg, acute vs chronic, granulomatous vs nongranulomatous, known cause vs unknown cause, primary lung disease vs secondary to systemic disease, history of smoking vs no smoking history).

Lung abscess is a necrotizing lung infection characterized by a pus-filled cavitary lesion. It is most commonly caused by aspiration of oral secretions by patients who have impaired consciousness. Symptoms are persistent cough, fever, sweats, and weight loss. Diagnosis is based primarily on chest x-ray. Treatment usually is with clindamycin or combination beta-lactam/beta-lactamase inhibitors.

Mediastinal masses are caused by a variety of cysts and tumors; likely causes differ by patient age and by location of the mass (anterior, middle, or posterior mediastinum). The masses may be asymptomatic (common in adults) or cause obstructive respiratory symptoms (more likely in children). Testing involves CT with biopsy and adjunctive tests as needed. Treatment differs by cause.

Pneumonia is acute inflammation of the lungs caused by infection. Initial diagnosis is usually based on chest x-ray and clinical findings. Causes, symptoms, treatment, preventive measures, and prognosis differ depending on whether the infection is bacterial, mycobacterial, viral, fungal, or parasitic; whether it is acquired in the community or hospital; whether it occurs in a patient treated with mechanical ventilation; and whether it develops in a patient who is immunocompetent or immunocompromised.

Pulmonary embolism is the occlusion of pulmonary arteries by thrombi that originate elsewhere, typically in the large veins of the legs or pelvis. Risk factors for pulmonary embolism are conditions that impair venous return, conditions that cause endothelial injury or dysfunction, and underlying hypercoagulable states. Symptoms of pulmonary embolism are nonspecific and include dyspnea, pleuritic chest pain, and, in more severe cases, light-headedness, presyncope, syncope, or cardiorespiratory arrest. Signs are also nonspecific and may include tachypnea, tachycardia, and in more severe cases, hypotension. Diagnosis of pulmonary embolism is most commonly accomplished with CT angiography, although ventilation/perfusion scanning is sometimes required. Pulmonary embolism treatment is with anticoagulants and, sometimes, clot dissolution with systemic or catheter-directed thrombolysis or catheter or surgical removal. When anticoagulation is contraindicated, an inferior vena caval filter should be placed. Preventive measures include anticoagulants and/or mechanical compression devices that are applied to the legs in hospitalized patients.

Pulmonary hypertension is increased pressure in the pulmonary circulation. It has many secondary causes; some cases are idiopathic. In pulmonary hypertension, pulmonary vessels become constricted and/or obstructed. Severe pulmonary hypertension leads to right ventricular overload and failure. Symptoms are fatigue, exertional dyspnea, and, occasionally, chest discomfort and syncope. Diagnosis is made by finding elevated pulmonary artery pressure (estimated by echocardiography and confirmed by right heart catheterization). Treatment is with pulmonary vasodilators and diuretics. In some advanced cases, lung transplantation is an option. Prognosis is poor overall if a treatable secondary cause is not found.

Chest physiotherapy consists of external mechanical maneuvers, such as chest percussion, postural drainage, and vibration, to augment mobilization and clearance of airway secretions. It is indicated for patients in whom cough is insufficient to clear thick, tenacious, copious, or loculated secretions. Examples include patients with

Sarcoidosis is an inflammatory disorder resulting in noncaseating granulomas in one or more organs and tissues; etiology is unknown. The lungs and lymphatic system are most often affected, but sarcoidosis may affect any organ. Pulmonary symptoms range from none to cough, exertional dyspnea and, rarely, lung or other organ failure. Diagnosis usually is first suspected because of pulmonary involvement and is confirmed by chest x-ray, biopsy, and exclusion of other causes of granulomatous inflammation. First-line treatment is corticosteroids. Prognosis is excellent for limited disease but poor for more advanced disease.

Central sleep apnea (CSA) is a heterogeneous group of conditions characterized by changes in ventilatory drive without airway obstruction. Most of these conditions cause asymptomatic changes in breathing pattern during sleep. The diagnosis is based on clinical findings and, when necessary, confirmed by polysomnography. Treatment is supportive.

Lung tumors may be