Source: Rachel Liu, BAO, MBBCh, Emergency Medicine, Yale School of Medicine, New Haven, Connecticut, USA

A tension pneumothorax is a life-threatening situation in which excess air is introduced into the pleural space surrounding the lung, either through trauma to the chest cavity or as a spontaneous leak of air from the lung itself. Air trapped within the pleural space causes separation of the lung from the chest wall, disrupting normal breathing mechanisms. Pneumothorax may be small without conversion to tension, but when there is a significant and expanding amount of air trapped in the pleural cavity, the increasing pressure from this abnormal air causes the lung to shrink and collapse, leading to respiratory distress. This pressure also pushes the mediastinum (including the heart and great vessels) away from its central position, causing inability of blood to return to the heart and diminishing the cardiac output. Tension pneumothoraces cause chest pain, extreme shortness of breath, respiratory failure, hypoxia, tachycardia, and hypotension. They need to be relieved emergently when a patient is in extremis.

Tension pneumothoraces are definitively managed by procedures that allow removal of trapped air, such as insertion of a chest tube. However, materials for chest tube placement are typically not available outside of the hospital setting. Temporizing measures are needed in deteriorating patients prior to hospital arrival or while chest tube materials are being gathered. In these situations, urgent needle thoracostomy (also called "needle decompression") is performed. Simply, it is the insertion of a large-bore needle or cannula through the chest wall and into the pleural space to allow air within the pleural cavity to escape. If a catheter or cannula is not immediately available, the procedure may be performed with a long, large-bore needle attached to a syringe. Air can be aspirated out of the pleural space with the syringe. A metal needle cannot stay in the pleural cavity, as the sharp tip may cause further damage; thus, it would need to be removed from the chest wall once air is aspirated.

1. Assessment of the patient

1. Place the patient on a monitor and review for tachycardia, tachypnea, hypoxia or hypotension.
2. Perform general inspection, observing patients for tachypnea, shallow respirations, and inability to speak full sentences. Note tracheal deviation, distension of neck veins, or cyanosis, which are later findings heralding tension pneumothorax that will deteriorate into cardiorespiratory arrest.
3. Auscultate both lungs to discriminate decreased or absent breath sounds on

Needle thoracostomy is a relatively easy procedure to temporize a patient in extremis from a tension pneumothorax before a chest tube can be placed. Penetration of the chest wall muscle, subcutaneous tissue, and pleura may require significant force, so a stabbing motion of needle entry may be necessary. The most common reason for failure of this procedure is that the needle length is not sufficient enough to reach the pleura. Some patients have significant chest wall thicknesses that standard needles may not penetrate. B