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a pneumothorax in which air enters the pleural cavity and is trapped during expiration; intrathoracic pressure builds to levels higher than atmospheric pressure, compresses the lung, and may displace the mediastinum and its structures toward the opposite side, with consequent cardiopulmonary impairment.
Synonym(s): pressure 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.
tension pneumothoraxA life-threatening emergency caused by air under pressure in the pleural space due to a one-way valve mechanism, which allows increased entry of air and eventually complete lung collapse on the affected side, accompanied by mediastinal shift of thoracic organs (heart, trachea, oesophagus) 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.
Penetrating trauma to the chest, infection, mechanical ventilation with high pressures, and as a complication of CPR.
Chest tube drainage, or pleurodesis.
tension pneumothoraxCritical 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.
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.
air leaks from a discontinuity in the lung into the pleural cavity.
artifactual increased radiolucency of the thorax resembling free air in the pleural cavity.
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.
caused by an open wound in the chest wall.
due to an unknown cause.
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.