胸腔穿刺

A tension pneumothorax occurs when excess air becomes trapped in the pleural space surrounding the lung, either from chest trauma or spontaneous lung leakage. The increasing pressure causes the lung to collapse and pushes the mediastinum away from its central position, preventing blood return to the heart and reducing cardiac output. This leads to respiratory failure, hypoxia, and hypotension.

Needle thoracostomy is performed as a temporizing measure when patients are deteriorating and chest tube materials are unavailable, such as outside hospital settings or while equipment is being gathered. It provides urgent relief of trapped air until definitive management with tube thoracostomy chest tube placement procedure can be performed in a hospital environment.

Needle thoracostomy involves inserting a large-bore needle or cannula through the chest wall into the pleural space to allow trapped air to escape. If a catheter is unavailable, a long, large-bore needle attached to a syringe can be used to aspirate air directly from the pleural cavity, providing immediate pressure relief.

Needle thoracostomy can be performed using a large-bore cannula or catheter, which can remain in the pleural space. Alternatively, if a catheter is not immediately available, a long, large-bore needle attached to a syringe can be used to aspirate air, though the metal needle must be removed after air aspiration to prevent further tissue damage.

Tension pneumothorax presents with chest pain, extreme shortness of breath, respiratory distress, and respiratory failure. Patients also experience hypoxia, tachycardia, and hypotension. These severe symptoms indicate the patient is in extremis and requires emergency needle decompression to restore normal breathing and cardiac function.

A metal needle cannot remain in the pleural cavity because its sharp tip may cause additional tissue damage to the lung or surrounding structures. After air is aspirated using a needle and syringe, the needle must be withdrawn from the chest wall, leaving only the catheter in place if one was used.

Air trapped in the pleural cavity causes the lung to separate from the chest wall and collapse, disrupting normal breathing mechanisms. The increasing pressure also displaces the mediastinum, including the heart and great vessels, preventing blood from returning to the heart and significantly reducing cardiac output, leading to shock.