Pneumothorax is a medical condition in which air or another gas accumulates within the pleural space between the lungs and lining of the chest wall. This condition can affect one or both lungs and can either be open or closed. Open pneumothorax occurs when a defect in the chest wall allows air to escape from the pleural space. Closed or tension pneumothorax occurs when air accumulates within the pleural space and can't escape. Cours ide refers to the type of treatment used to treat pneumothorax. This type of treatment involves creating an opening in the chest wall to allow the air within the pleural space to escape. This is usually done by inserting a needle or chest tube into the chest wall. This opening allows air to escape from the pleural space, relieving any pressure that has built up in the lungs. In some cases, a small valve may be inserted along with the chest tube, which allows air to escape while preventing new air from entering the pleural space. This procedure is known as the Heimlich valve technique and is used to treat both open and closed pneumothorax. Once the air is allowed to escape, the pressure within the lungs can decrease and the lung can then begin to heal itself. Cours ide is often used as a short-term solution until the underlying cause of the pneumothorax can be identified and treated. If a more permanent solution is needed, surgery may be recommended to close the defect in the chest wall.