This involves the administration of local anesthetic and inserting a needle connected to a three-way tap; up to 2.5 liters of air (in adults) are removed. If there has been significant reduction in the size of the pneumothorax on subsequent X-ray, the remainder of the treatment can be conservative. This approach has been shown to be effective in over 50% of cases. Compared to tube drainage, first-line aspiration in PSP reduces the number of people requiring hospital admission, without increasing the risk of complications.Aspiration may also be considered in secondary pneumothorax of moderate size (air rim 1–2 cm) without breathlessness, with the difference that ongoing observation in hospital is required even after a successful procedure. American professional guidelines state that all large pneumothoraces – even those due to PSP – should be treated with a chest tube. Moderately sized iatrogenic traumatic pneumothoraces (due to medical procedures) may initially be treated with aspiration. Chest tube
A chest tube (or intercostal drain) is the most definitive initial treatment of a pneumothorax. These are typically inserted in an area under the axilla (armpit) called the "safe triangle", where damage to internal organs can be avoided; this is delineated by a horizontal line at the level of the nipple and two muscles of the chest wall (latissimus dorsi and pectoralis major). Local anesthetic is applied. Two types of tubes may be used. In spontaneous pneumothorax, small-bore (smaller than 14 F, 4.7 mm diameter) tubes may be inserted by the Seldinger technique, and larger tubes do not have an advantage.
Known lung diseases that may significantly increase the risk for pneumothorax are

In children, additional causes include measles, echinococcosis, inhalation of a foreign body, and certain congenital malformations (congenital pulmonary airway malformation and congenital lobar emphysema).11.5% of people with a spontaneous pneumothorax have a family member who has previously experienced a pneumothorax. The hereditary conditions – Marfan syndrome, homocystinuria, Ehlers–Danlos syndromes, alpha 1-antitrypsin deficiency (which leads to emphysema), and Birt–Hogg–Dubé syndrome – have all been linked to familial pneumothorax. Generally, these conditions cause other signs and symptoms as well, and pneumothorax is not usually the primary finding. Birt–Hogg–Dubé syndrome is caused by mutations in the FLCN gene (located at chromosome 17p11.2), which encodes a protein named folliculin. FLCN mutations and lung lesions have also been identified in familial cases of pneumothorax where other features of Birt–Hogg–Dubé syndrome are absent. In addition to the genetic associations, the HLA haplotype A2B40 is also a genetic predisposition to PSP. Traumatic
A traumatic pneumothorax may result from either blunt trauma or penetrating injury to the chest wall. The most common mechanism is due to the penetration of sharp bony points at a new rib fracture, which damages lung tissue. Traumatic pneumothorax may also be observed in those exposed to blasts, even though there is no apparent injury to the chest.They may be classified as "open" or "closed". In an open pneumothorax, there is a passage from the external environment into the pleural space through the chest wall.