Picture a hunter out in the woods that is struck by a stray .556 round to the thoracic region of the body. Air is being sucked into the thoracic cavity through the chest wall instead of into the lungs through the airways. As air fills the pleural space through the opening of an open pneumothorax, the traumatic wound can act as a one-way valve and will not allow the air to exit. If not treated properly this will lead to a cascading effect on the patient. The pressure will increases and begin to collapse the lung. Once the lung has collapsed, the pressure will begin to compress the heart, and the mediastinum will shift toward the uninjured lung. This entire process leads to a life-threatening condition known as a tension pneumothorax. From