Explanation

Decreased tactile fremitus over the affected lung field is an expected finding in this patient who has signs and symptoms of a right-sided spontaneous pneumothorax. A pneumothorax is accumulation of air in the pleural space, that may be primary (occurring in the absence of underlying lung disease) or secondary to an existing pulmonary disorder. In this patient, a primary pneumothorax is the most likely etiology. Tall, thin males between ages 10 and 30 years have a predisposition to suffering rupture of subpleural apical blebs due to high negative intrapleural pressures. Patients with a spontaneous pneumothorax will generally display symptoms relative to the size of the pneumothorax. Chest pain and dyspnea are usually present, though degree depends on the extent of the pneumothorax. Most patients will note that symptoms began at rest. Patients with underlying asthma or COPD may present hypotensive and in life-threatening respiratory failure. A physical exam will reveal decreased or absent breath sounds, decreased tactile fremitus, and hyperresonance of the affected lung field. Diagnostic tests might include a chest radiograph, which would show an abnormally radiolucent costophrenic sulcus, also known as the deep sulcus sign. Though rarely indicated acutely, an arterial blood gas would show hypoxemia and respiratory alkalosis. Treatment depends on the extent of pneumothorax. A small pneumothorax, affecting less than 20% of a hemithorax, can be observed. Simple aspiration drainage of pleural air with a small-bore catheter may be needed in larger pneumothoraces.

Left-sided hyperresonance (B) would be expected if the pneumothorax were occurring in the patient’s left lung. A mediastinal shift to the right (C) would generally only be seen in a patient with a tension pneumothorax affecting his left lung field. Tension pneumothorax refers to a pneumothorax that is so large that positive pressure in the affected side causes displacement of mediastinal structures and results in cardiopulmonary compromise. Patients with tension pneumothorax are generally more acutely ill with cyanosis and hypotension at presentation. This patient’s heart rate and blood pressure are stable, making tension pneumothorax unlikely. Similarly, a tracheal shift to the left side (D) would usually only occur in patients with a right-sided tension pneumothorax.