Emphysema

1) A lung condition featuring an abnormal accumulation of air in the lung's many tiny air sacs, a tissue called alveoli. As air continues to collect in these sacs, they become enlarged, and may break, or be damaged and form scar tissue. Emphysema is strongly associated with smoking cigarettes, a practice that causes lung irritation. It can also be associated with or worsened by repeated infection of the lungs, such as is seen in chronic bronchitis. The best response to the early warning signs of emphysema is prevention: stop smoking and get immediate treatment for incipient lung infections. Curing established emphysema is not yet possible. Because patients don’t have an adequate amount of space in the lungs to breathe, they gasp for breath, and may not be able to obtain enough oxygen. Those with severe emphysema usually end up using an oxygen machine to breathe. In some cases, medication may be helpful to ease symptoms or to treat infection in already-damaged lungs. 2) The escape of air into other body tissues, as may occur during surgery. This is called surgical emphysema.

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1. Presence of air in the interstices of the connective tissue of a part. 2. A condition of the lung characterized by increase beyond the normal in the size of air spaces distal to the terminal bronchiole (those parts containing alveoli), with destructive changes in their walls and reduction in their number. Clinical manifestation is breathlessness on exertion, due to the combined effect (in varying degrees) of reduction of alveolar surface for gas exchange and collapse of smaller airways with trapping of alveolar gas in expiration; this causes the chest to be held in the position of inspiration (“barrel chest”), with prolonged expiration and increased residual volume. Symptoms of chronic bronchitis often, but not necessarily, coexist. Two structural varieties are panlobular (panacina) e. and centrilobular (centriacinar) e.; paracicatricial, paraseptal, and bullous e. are also common. SYN: pulmonary e.. [G. inflation of stomach, etc. fr. en, in, + physema, a blowing, fr. physa, bellows]

- alveolar duct e. e. in which the primary involvement is in the alveolar ducts and respiratory bronchioles, as opposed to panacinar e..

- bullous e. e. in which the enlarged airspaces are 1 to several cm in diameter, often visible on chest radiographs. Thin-walled air sacs, under tension, compress pulmonary tissue, either single or multiple; sometimes amenable to surgical resection with improvement in pulmonary function.

- centriacinar e. SYN: centrilobular e..

- centrilobular e. e. affecting the central portion of secondary pulmonary lobules, around the central bronchiole, typically involving the superior part of the lungs or lobes; may be related to inflammation of the bronchioles and to the effects of inhaled dust, which aggregates next to respiratory bronchioles; seen in coalworker's pneumoconiosis and (in mild form) asymptomatic city dwellers. SYN: centriacinar e..

- compensating e., compensatory e. increase in the air capacity of a portion of the lung when another portion is consolidated, shrunken, or unable to perform its respiratory function; the alveoli are distended, but there is no destruction of alveolar walls, and hence, no true e., as this term is now defined.

- congenital lobar e. common cause of neonatal respiratory distress which usually involves the left upper lobe.

- cutaneous e. SYN: subcutaneous e..

- diffuse obstructive e. the major component of chronic obstructive lung disease.

- ectatic e. obstructive airway disease with areas of dilation of alveoli acini. Seen primarily in association with inherited deficiency of α-1-antitrypsin. See panlobular e..

- familial e. e. inherited in association with severe α-1 antitrypsin deficiency. It may occur as an isolated feature [MIM*130700, 130710] or with cutis laxa and hemolytic anemia [MIM*235360].

- gangrenous e. SYN: gas gangrene.

- generalized e. SYN: panlobular e..

- increased markings e. a term applied to mixed obstructive lung disease in which radiographic findings of e. coexist with nonvascular shadows, probably related to bronchial inflammation.

- interlobular e. interstitial e. in the connective tissue septa between the pulmonary lobules.

- interstitial e. 1. presence of air in the pulmonary tissues consequent upon rupture of the air cells; 2. presence of air or gas in the connective tissue.

- intestinal e. SYN: pneumatosis cystoides intestinalis.

- irregular e. e. that shows no consistent relationship to any portion of the acinus; always associated with fibrosis.

- mediastinal e. SYN: pneumomediastinum.

- panacinar e. SYN: panlobular e..

- panlobular e. e. affecting all parts of the secondary pulmonary lobule, typically involving the inferior part of the lung and often asociated with a α₁-antitrypsin deficiency. SYN: generalized e., panacinar e..

- paracicatricial e. dilated terminal air spaces adjacent to a scar in the lung. SEE ALSO: paraseptal e..

- paraseptal e. e. involving the periphery of the pulmonary lobules. SYN: scar e..

- pulmonary e. SYN: e. (2).

- scar e. SYN: paraseptal e..

- senile e. e. consequent upon the physiologic atrophy of old age.

- subcutaneous e. the presence of air or gas in the subcutaneous tissues. SYN: aerodermectasia, cutaneous e., pneumoderma, pneumohypoderma.

- subgaleal e. collection of air or gas between the inner layer of the scalp and the cranium.

- surgical e. subcutaneous e. from gas trapped in the tissues by an operation or injury, frequently seen after carbon dioxide insufflation during laproscopic procedures.

- unilateral lobar e. radiographically hyperlucent lobe (or lung) secondary to bronchiolitis obliterans, with air trapping. SYN: Macleod syndrome, Swyer-James syndrome (1), Swyer-James-MacLeod syndrome.

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em·phy·se·ma .em(p)-fə-'zē-mə, -'sē- n a condition characterized by air-filled expansions in interstitial or subcutaneous tissues specif a condition of the lung that is marked by distension and eventual rupture of the alveoli with progressive loss of pulmonary elasticity, that is accompanied by shortness of breath with or without cough, and that may lead to impairment of heart action

em·phy·se·ma·tous -'zem-ət-əs, -'sem-, -'zēm-, -'sēm- adj

em·phy·se·mic -'zē-mik, -'sē- adj

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n.

air in the tissues. In pulmonary emphysema the air sacs (alveolus) of the lungs are enlarged and damaged, which reduces the surface area for the exchange of oxygen and carbon dioxide. Severe emphysema causes breathlessness, which is made worse by infections. There is no specific treatment, and the patient may become dependent on oxygen. The mechanism by which emphysema develops is not understood, although it is known to be particularly common in men in Britain and is associated with chronic bronchitis, smoking, and advancing age.

In surgical emphysema air may escape into the tissues of the chest and neck from leaks in the lungs or oesophagus; occasionally air escapes into other tissues during surgery, and bacteria may form gas in soft tissues. The presence of gas or air gives the affected tissues a characteristic crackling feeling to the touch, and it may be visible on X-rays. It is easily absorbed once the leak or production is stopped.

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em·phy·se·ma (em″fə-seґmə) [Gr. “an inflation”] 1. a pathological accumulation of air in tissues or organs. 2. pulmonary e. emphysematous adj