tension pneumothorax

tension pneumothorax

Etymology: L, tendere, to stretch; Gk, pneuma, air, thorax

the presence of air in the pleural space when pleural pressure exceeds alveolar pressure, caused by a rupture through the chest wall or lung parenchyma associated with the valvular opening. Air passes through the valve during coughing but cannot escape on exhalation. Unrelieved pneumothorax can lead to respiratory arrest.

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pneumothorax

entry of air into the pleural cavity in sufficient quantity to cause collapse of the lung and consequent respiratory embarrassment. If it is unilateral there is a mediastinal shift with displacement of the heart to the other side of the chest. Breath sounds are absent from the affected side.

Pneumothorax. By permission from Ettinger SJ, Feldman E, Textbook of Veterinary Internal Medicine, Saunders, 2004

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closed pneumothorax

air leaks from a discontinuity in the lung into the pleural cavity.

false pneumothorax

artifactual increased radiolucency of the thorax resembling free air in the pleural cavity.

iatrogenic pneumothorax

may occur following intrathoracic surgery or in association with procedures which involve entry into the pleural cavity, such as thoracentesis or placement of a chest drain.

open pneumothorax

caused by an open wound in the chest wall.

spontaneous pneumothorax

due to an unknown cause.

tension pneumothorax

a particularly dangerous form of pneumothorax that occurs when air escapes into the pleural cavity from a bronchus but cannot regain entry into the bronchus. As a result, continuously increasing air pressure in the pleural cavity causes progressive collapse of the lung tissue. If not relieved, it can lead to lung collapse and mediastinal shift.

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tension pneumothorax

Critical care A life-threatening emergency consisting of air under pressure in the pleural space, due to a one-way valve type mechanism, allowing ↑ entry of air and eventually complete lung collapse on the affected side, which is acompanied by mediastinal shift of thoracic organs–heart, trachea, esophagus, and great vessels towards the unaffected side of the chest, and compression of the opposite lung with compromise in the return flow of blood to the heart Etiology Penetrating trauma to the chest, infection, mechanical ventilation with high pressures, and as a complication of CPR Management Chest tube drainage, or pleurodesis. See Pneumothorax.