A tension pneumothorax results when air enters but does not exit the pleural space. Air in the pleural space accumulates and compresses the ipsilateral lung and vena cava, with a rapid decrease in cardiac output. The contralateral lung may suffer ventilation/perfusion mismatch. Subcutaneous air, tracheal deviation, jugulovenous distention (JVD), and diminished or hyperresonant ipsilateral breath sounds are clues. Subcutaneous emphysema may be visible on the neck and chest radiographs and is easily diagnosed by palpation. The released air from a tension pneumothorax can be heard escaping during a needle thoracostomy.
Management and Disposition
Treatment requires rapid recognition of the tension pneumothorax, frequently without benefit of chest radiographs. A 14-gauge or larger needle should be placed over the superior rib surface of the 2nd interspace in the midclavicular line. A rush of air with improvement of vital signs confirms the diagnosis. If there is no immediate improvement, do not hesitate to place a 2nd needle in the next interspace. A chest tube should be placed immediately.
Tension Pneumothorax. A 35-year-old man with severe asthma suffered respiratory arrest during transport by ambulance. He was intubated on arrival but soon became hard to ventilate and developed subcutaneous emphysema followed by hypotension. Needle thoracostomy produced a rush of air and bubbling from the needle with stabilization of vital signs. (Photo contributor: Stephen W. Corbett, MD.)
“Stacking” breaths in patients with obstructive lung disease trap air in the lungs and predispose to bleb rupture and pneumothorax. The pathophysiology of this disease requires a prolonged expiratory phase.
The diagnosis of a tension pneumothorax should be made clinically and treated immediately with needle or finger thoracostomy and tube thoracostomy.
Tension pneumothorax may be a consequence of positive-pressure ventilation in patients with undetected pneumothorax and a persistent air leak such as bronchopleural fistula.
Tension pneumothorax is a treatable cause of pulseless electrical activity (PEA).
Deep Sulcus Sign. Deepening of the left costophrenic angle is seen. Left to right mediastinal shift is also present suggesting a tension pneumothorax. (Photo contributor: Lawrence B. Stack, MD.)
Video 07-02: Normal Lung Sliding
Bedside ultrasound demonstrates visceral and parietal pleural sliding confirming absence of a pneumothorax.
Video 07-03: Pneumothorax on Ultrasound
Bedside ultrasound reveals absence of pleural sliding, suggesting pneumothorax.