mediastinal emphysema

emphysema /em·phy·se·ma/ (em″fĭ-se´mah)

1. a pathologic accumulation of air in tissues or organs.

2. pulmonary e.emphysem´atous

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atrophic emphysema  senile e.

bullous emphysema  single or multiple large cystic alveolar dilatations of lung tissue.

centriacinar emphysema , centrilobular emphysema focal dilatations of respiratory bronchioles rather than alveoli, throughout the lung among normal lung tissue.

congenital lobar emphysema  overinflation of a lung, usually in early life in one of the upper lobes, with respiratory distress.

hypoplastic emphysema  pulmonary emphysema due to a developmental anomaly, with fewer and abnormally large alveoli.

infantile lobar emphysema  congenital lobar e.

interlobular emphysema  air in the septa between lung lobules.

interstitial emphysema  air in the peribronchial and interstitial tissues of the lungs.

intestinal emphysema  pneumatosis cystoides intestinalis.

mediastinal emphysema  pneumomediastinum.

obstructive emphysema  that associated with partial bronchial obstruction that interferes with exhalation.

panacinar emphysema , panlobular emphysema a type characterized by enlargement of air spaces throughout the acini.

pulmonary emphysema  abnormal increase in size of lung air spaces distal to the terminal bronchioles.

pulmonary interstitial emphysema  (PIE) a condition seen mostly in premature infants, in which air leaks from lung alveoli into interstitial spaces, often because of underlying lung disease or use of mechanical ventilation.

senile emphysema  overdistention and stretching of lung tissues due to atrophic changes.

subcutaneous emphysema  air or gas in subcutaneous tissues, usually caused by intrathoracic injury.

surgical emphysema  subcutaneous emphysema following surgery.

vesicular emphysema  panacinar e.

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mediastinal emphysema

n.

A deflection of air, usually from a ruptured emphysematous bleb in the lung, into the mediastinal tissue.

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emphysema

a pathological accumulation of air in tissues. The air may derive from a skin laceration and be drawn in by the movements of muscles. A discontinuity of the tracheal mucosa is a common cause, either by way of laceration or ulceration. Extension from a pulmonary lesion is also common. The syndrome resulting depends on the location of the air. See also pulmonary emphysema and subcutaneous emphysema (below).

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acute bovine pulmonary emphysema

see atypical interstitial pneumonia.

alveolar emphysema

see pulmonary emphysema (below).

bullous emphysema

emphysema in which bullae form in areas of lung tissue so that these areas do not contribute to respiration.

conjunctival emphysema

may occur after head trauma which permits escape of air from the paranasal sinuses.

fetal emphysema

see emphysematous/putrescent fetus.

generalized emphysema

widespread distribution of air, including subcutaneous tissues, seen with pneumomediastinum.

hypoplastic emphysema

pulmonary emphysema due to a developmental abnormality, resulting in a reduced number of alveoli, which are abnormally large.

interlobular emphysema

accumulation of air in the septa between lobules of the lungs.

interstitial emphysema

presence of air in the peribronchial and interstitial tissues of the lungs.

intestinal emphysema

a condition marked by accumulation of gas under the tunica serosa of the intestine.

lobar emphysema

emphysema involving less than all the lobes of the affected lung.

mediastinal emphysema

see pneumomediastinum.

orbital emphysema

may occur after trauma to the head which permits escape of air from the paranasal sinuses; appears as swelling with crepitus under the conjunctiva or periocular skin.

panacinar emphysema, panlobular emphysema

generalized obstructive emphysema affecting all lung segments, with atrophy and dilatation of the alveoli and destruction of the vascular bed.

pulmonary emphysema

distention of the lung caused by overdistention of alveoli and rupture of alveolar walls (alveolar emphysema) and in some cases escape of air into the interstitial spaces (interstitial emphysema). It is a common pathological finding in many diseases of the lung in all species, but also occurs independently, especially in horses, as a principal lesion in chronic obstructive pulmonary disease. It is also a prominent lesion in bovine atypical interstitial pneumonia. It is always secondary to a primary lesion which effectively traps an excessive amount of air in the alveoli. It is characterized clinically by cough, dyspnea, forced expiratory effort and poor work tolerance. A double expiratory effort is a characteristic sign—hence broken wind.

subconjunctival emphysema

occurs with fractures involving the paranasal sinuses.

subcutaneous emphysema

air or gas in the subcutaneous tissues. The characteristic lesion is a soft, mobile swelling which crackles like stiff paper when palpated. There is no pain, nor heat and no ill effects unless the pharyngeal area is sufficiently involved to cause asphyxia.

surgical emphysema

subcutaneous emphysema following operation.

unilateral emphysema

emphysema affecting only one lung, frequently due to congenital defects in circulation.

vesicular emphysema

see panacinar emphysema (above).

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mediastinal

of or pertaining to the mediastinum.

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mediastinal abscess

an abscess that causes systemic signs of toxemia and fever but also severe pain with each inspiration, causing grunting as in pleurisy but without the auscultatory findings of pleurisy.

mediastinal cyst

remnants of branchial pouches may be found in the anterior mediastinum, particularly in brachycephalic dogs; bronchogenic cysts are found in the posterior mediastinum.

mediastinal emphysema

see pneumomediastinum.

mediastinal flutter

movement of the tissues and organs of the mediastinum back and forth with each movement of air in and out of an open sucking wound in the thoracic cavity. The condition can produce serious impairment of cardiopulmonary function and is fatal if not treated promptly. Signs are similar to those of mediastinal shift (see below).

mediastinal lymph node enlargement

a condition due to abscess formation or neoplastic growth which may cause obstruction to the esophagus and dysphagia, or to the bronchi, causing inspiratory dyspnea. If it is in the anterior chest and of considerable size, it may mimic congestive heart failure, with jugular vein engorgement and edema of the brisket.

mediastinal neoplasm

characterized by progressive weight loss, reduced exercise tolerance, dyspnea, hydrothorax, areas of dullness on auscultation or percussion over lungs, neoplastic cells in pleural fluid if lesion intrudes into pleural cavity.

mediastinal shift

a shifting or moving of the tissues and organs that comprise the mediastinum (heart, great vessels, trachea and esophagus) to one side of the chest cavity. The condition occurs when a severe injury to the chest causes the entrapment of air in the pleural space (tension pneumothorax). As the volume of air increases on the affected side, the lung collapses and the organs and tissues of the mediastinum are crowded to the opposite side of the chest. This can produce compression of the other lung and kinking or twisting of one or more of the great blood vessels, which in turn seriously impairs blood flow to and from the heart.

mediastinal testis

a partial septum of the testis that contains the rete testis.

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mediastinal emphysema

Pneumomediastinum Surgery Air in mediastinal soft tissues which may be linked to perforation of the trachea. See Mediastinal crunch, Mediastinum.