pneumothorax is a collapsed lung. Defined as the presence of air or gas in the pleural cavity (ie, the potential space between lungs and chest wall. ), which can impair oxygenation and/or ventilation. The clinical results are dependent on the degree of collapse of the lung on the affected side. If the pneumothorax is significant, it can cause a shift of the mediastinum and compromise hemodynamic stability. Air can enter the intrapleural space through a communication from the chest wall (ie, trauma) or through the lung parenchyma across the visceral pleura..
. Common findings among the types of pneumothoraces include the following:
• Spontaneous and iatrogenic pneumothorax : Tachycardia most common finding; tachypnea and hypoxia may be present
• Tension pneumothorax: Variable findings; respiratory distress and chest pain; tachycardia; ipsilateral air entry on auscultation; breath sounds absent on affected hemithorax; trachea may deviate from affected side; thorax may be hyperresonant; jugular venous distention and/or abdominal distention may be present
• Pneumomediastinum: Variable or absent findings; subcutaneous emphysema is the most consistent sign; Hamman sign—a precordial crunching noise synchronous with the heartbeat and often accentuated during expiration—has a variable rate of occurrence, with one series reporting 10%