Subcutaneous and mediastinal emphysema. Pathophysiology, diagnosis, and management

TLDR

Subcutaneous emphysema and pneumomediastinum frequently arise in critically ill patients from trauma, infections, or pressure gradients, and air can spread through connected fascial planes, but the presence of air alone is not dangerous—prompt recognition of the underlying cause is essential. Diagnosis relies on clinical examination and chest radiography, and while some trauma‑related cases may need surgery, routine chest tubes, tracheostomy, or mediastinal drains are not recommended. Arch Intern Med 1984;144:1447-1453.

Abstract

• Subcutaneous emphysema and pneumomediastinum occur frequently in critically ill patients in association with blunt or penetrating trauma, soft-tissue infections, or any condition that creates a gradient between intra-alveolar and perivascular interstitial pressures. A continuum of fascial planes connects cervical soft tissues with the mediastinum and retroperitoneum, permitting aberrant air arising in any one of these areas to spread elsewhere. Diagnosis is made in the appropriate clinical setting by careful physical examination and inspection of the chest roentgenogram. While the presence of air in subcutaneous or mediastinal tissue is not dangerous in itself, prompt recognition of the underlying cause is essential. Certain trauma-related causes may require surgical intervention, but the routine use of chest tubes, tracheostomy, or mediastinal drains is not recommended. (<i>Arch Intern Med</i>1984;144:1447-1453)