"Gas exchange is impaired by collapse of the affected lung and reduced alveolar surface area. The decreased ventilation–perfusion (V/Q) ratio causes intrapulmonary shunting of deoxygenated blood causing hypoxaemia. Loss of compliance and increased work of breathing further impair ventilation however fatalities are rare in healthy adults without pre-existing lung disease. Most cases of clinical deterioration are due to hypoxaemia or underlying cardiopulmonary disease 28."
"iatrogenic:"
"trauma:"
"A simple pneumothorax is a non-communicating pneumothorax without tension."
"An occult pneumothorax refers to one missed on initial imaging, often a supine/semierect AP chest radiograph 24."
"Historical methods for estimating the percentage volume of pneumothorax from an erect PA radiograph include the Collins method 1, the Rhea method 20 and the Light index 21."
"beam-hardening artifact from concentrated iodinated contrast medium in a brachiocephalic vein or the SVC"
"Langerhans cell histiocytosis (LCH)"
"British Thoracic Society (BTS) guidelines (2010): measured from chest wall to lung edge at the level of the hilum 12"
"American College of Chest Physicians guidelines (2001): measured from thoracic cupola to lung apex 13"
Expected headings
"Primary spontaneous"
"Secondary spontaneous"
"Iatrogenic/traumatic"
"Others"
"Unusual forms"
"Presentation is variable and may range from no symptoms to severe dyspnoea with tachycardia and hypotension. Patients breathing spontaneously present with hypoxaemia and respiratory distress, whereas ICU patients on positive pressure ventilation present with rapid deterioration, hypoxaemia and circulatory collapse leading to cardiac arrest."
"Symptoms in secondary pneumothorax depend on the nature and severity of the underlying lung disease. Pain is less significant than dyspnoea which can be severe. This is often accompanied by significant hypoxaemia, hypotension and hypercapnia, which can be fatal 26."
"Spontaneous pneumothorax can progressively enlarge if there is a persistent visceral pleural leak; the loss of negative pleural pressure allows the ipsilateral lung to collapse, and with increasing pneumothorax volume the rib spacing increases, and the diaphragm and mediastinum are pushed away. Expansion of the contralateral lung is restricted."
"When the underlying lung is abnormal, a pneumothorax is referred to as secondary spontaneous. There are many pulmonary diseases which predispose to pneumothorax including:"
"Pneumothorax is derived from two Greek words, πνευμα (pneumα) meaning breath and θωραξ (thorax) meaning breastplate. The synonym, aerothorax, which is rarely, if ever, seen in modern medicine also has Greek roots, from αερος (aero) meaning air 22,23."