This patient's chest CT scan demonstrated a right-sided pneumothorax. He also had a left-sided pulmonary artery thrombus and a suspicious left lower-lobe nodule shown on other images from this CT scan (not shown). Bilateral lower-extremity ultrasound studies were negative for deep vein thrombosis.
Pneumothorax is a collection of air or gas in the pleural space. It can occur either spontaneously or due to trauma (including iatrogenic injury). The normal pleural space has a negative pressure of -5 cm H2O (relative to atmospheric pressure) due to the recoil force of the lungs, which helps to prevent the lung from total collapse even at the end of expiration. In pneumothorax, the air creates a positive intrapleural pressure, thereby preventing lung expansion and causing compressive atelectasis and even collapse, depending on the severity. A pneumothorax can even progress to the point that it compresses the mediastinum and impairs venous return, and may thereby induce hypotension and shock.
Spontaneous pneumothorax is defined by the absence of a preceding intrathoracic trauma or invasive procedure that breaches the thoracic cavity. A spontaneous pneumothorax in a patient with no underlying lung disease is considered a primary spontaneous pneumothorax (PSP). A spontaneous pneumothorax in a person with underlying lung disease (eg, COPD) is considered a secondary spontaneous pneumothorax (SSP). PSP has been attributed to the rupture of a subpleural bleb from congenital anomalies, inflammation of the bronchioles, and disturbances of the collateral ventilation. PSP has a predilection for tall, thin males; the incidence is increased in individuals with Marfan syndrome and homocystinuria.
The relative risk for PSP is 7 times higher in light smokers (1-12 cigarettes/day) and up to 102 times higher in heavy smokers (> 22 cigarettes/day), compared with nonsmokers. SSP is attributed to the rupture of alveoli or bullae, most commonly as a result of COPD. SSP is particularly detrimental, as it affects patients with underlying lung disease and pre-existing respiratory compromise.
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Cite this: Sudden-Onset Chest Pain in an 80-Year-Old Man With COPD - Medscape - Mar 24, 2011.