effusion

1. The escape of fluid from the blood vessel s or lymphatics into the tissues or a cavity. 2. A collection of the fluid effused. [L. effusio, a pouring out]

- complex pleural e. a pleural e. without actual infection but with signs of a high degree of inflammation ( e.g., low pH, low glucose, high lactate dehydrogenase, many white cells).

- joint e. increased fluid in synovial cavity of a joint.

- loculated pleural e. pleural e. that is confined to one or more fixed pockets in the pleural space.

- middle-ear e. a condition in which the air in the middle ear has been replaced with serous or mucoid fluid as a consequence of otitis media. SYN: secretory otitis media, serous otitis media.

- parapneumonic e. pleural e. associated with pneumonia

- pericardial e. increased fluid within the pericardial sac; can cause circulatory compromise by compression of the heart; most often caused by inflammation, infection, malignancy, and uremia. SYN: dropsy of pericardium.

- pleural e. increased fluid in the pleural space; can cause shortness of breath by compression of the lung and/or increased intrathoracic pressure resulting in mediastinal shift and increased work of breathing; a transudative e. has low protein content and is usually due to heart failure, uremia, or hypoalbuminemia; an exudative e. has high protein and cell count and is due most often to inflammation, malignancy, or infection; an infected pleural e. is an empyema; a pleural e. associated with pneumonia is a parapneumonic e.; a pleural e. without actual infection but with signs of a high degree of inflammation ( e.g., low pH, low glucose, high lactate dehydrogenase, many white cells) is a complex pleural e. and is frequently associated with pneumonia; a loculated pleural e. is not free-flowing in the pleural space but rather confined to one or more fixed pockets. SYN: hydrothorax.

- subpulmonic e. a collection of fluid in the pleural space mostly located radiographically between the diaphragm and the basal surface of the lung.

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ef·fu·sion i-'fyü-zhən, e- n

1 a) the escape of a fluid from anatomical vessels by rupture or exudation

b) the flow of a gas through an aperture whose diameter is small as compared with the distance between the molecules of the gas

2) the fluid that escapes by extravasation see PLEURAL EFFUSION

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n.

1. the escape of pus, serum, blood, lymph, or other fluid into a body cavity as a result of inflammation or the presence of excess blood or tissue fluid in an organ or tissue.

2. fluid that has escaped into a body cavity.

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ef·fu·sion (ə-fuґzhən) [L. effusio a pouring out] 1. the escape of fluid into a part or tissue, as an exudation or a transudation. 2. an effused material, which may be classified according to protein or cellular content as an exudate or transudate.