Pneumothorax

Key Features

Essentials of Diagnosis

• Sudden onset shortness of breath

• Focal area of absent breath sounds on chest auscultation

• Shift of the trachea away from the area with absent breath sounds

General Considerations

• Can occur spontaneously in newborns and in older children

• More commonly results from

  • Birth trauma

  • Positive pressure ventilation

  • Underlying obstructive or restrictive lung disease

  • Rupture of a congenital or acquired lung cyst

• Can also occur as an acute complication of tracheostomy

• Associated conditions include

  • Pneumomediastinum

  • Pneumopericardium

  • Pneumoperitoneum

  • Subcutaneous emphysema

Clinical Findings

Symptoms and Signs

• Clinical spectrum can vary from asymptomatic to severe respiratory distress

• Associated symptoms include cyanosis, chest pain, and dyspnea

• Physical examination may reveal decreased breath sounds and hyperresonance to percussion on the affected side with tracheal deviation to the opposite side

• When pneumothorax is under tension, cardiac function may be compromised, resulting in hypotension or narrowing of the pulse pressure

• Pneumopericardium is a life-threatening condition that presents with muffled heart tones and shock

Differential Diagnosis

• Diaphragmatic hernia

• Lung cysts

• Congenital lobar emphysema

• Cystic adenomatoid malformation

Diagnosis

• Chest radiography

  • Usually demonstrates presence of free air in the pleural space

  • When the pneumothorax is large and under tension, compressive atelectasis of the underlying lung and shift of the mediastinum to the opposite side may be observed

  • Cross-table lateral and lateral decubitus radiographs can aid in the diagnosis of free air

  • Pneumopericardium is identified by the presence of air completely surrounding the heart, whereas in patients with pneumomediastinum, the heart and mediastinal structures may be outlined with air, but the air does not involve the diaphragmatic cardiac border

• Chest CT scan may be helpful with recurrent spontaneous pneumothoraces to look for subtle pulmonary disease not seen on chest radiograph

Treatment

• Small (< 15%) or asymptomatic pneumothoraces

  • Usually do not require treatment

  • Can be managed with close observation

• Larger or symptomatic pneumothoraces

  • Require drainage

  • Inhalation of 100% oxygen to wash out blood nitrogen can be tried

• Needle aspiration should be used to relieve tension acutely, followed by chest tube or pigtail catheter placement

• Pneumopericardium

  • Requires immediate identification

  • If clinically symptomatic, needle aspiration necessary to prevent death, followed by pericardial tube placement

Outcome

Prognosis

• Recurrences are common in older patients with spontaneous pneumothorax

• Sclerosing and surgical procedures are often required

References