Pulmonary Interstitial Emphysema

  • Etiology: Complication of respiratory distress syndrome and mechanical ventilation where barotrauma from mechanical ventilation in patients with respiratory distress syndrome causes rupture of overdistended pulmonary alveoli leading to entry of air into pulmonary interstitium
  • Imaging CXR: Air which appears as multiple circular bubbly and branching interstitial lucencies in hyperinflated lungs
  • DDX:
    — Airbronchograms of respiratory distress syndrome: Branching air bubbles with orderly tapering of air bronchograms while pulmonary interstitial emphysema is thicker and blacker without orderly tapering of air bronchograms
    — Chronic lung disease: Occurs in older patients while pulmonary interstitial emphysema occurs in younger patients
  • Complications: Prelude to pneumomediastinum and pneumothorax which often is a tension pneumothorax
  • Treatment: Decrease ventilator pressure
  • Clinical: Extremely uncommon in patients besides premature infants with respiratory distress syndrome

Radiology Cases of Pulmonary Interstitial Emphysema

CXR of pulmonary interstitial emphysema
CXR shows air branching throughout the pulmonary interstitium in the left lung.
CXR of pulmonary interstitial emphysema
CXR AP shows a branching bubbly appearance to the right lung along with air in the superior mediastinum.
CXR of pneumopericardium and right pulmonary interstitial emphysema which resulted in a right tension pneumothorax
CXR AP at 2 days of age (above) shows air surrounding the heart and not rising above the great vessels. Air is also present in the right pulmonary interstitium in a branching pattern from the hilum to the periphery. CXR AP at 3 days of age (below) shows air no longer surrounding the heart and interval development of a large amount of lucency in the right pleural space with mediastinal shift to the left.
CXR of pneumothorax
Supine CXR shows a large amount of air in the right pleural space with inversion of the right hemidiaphragm and mediastinal shift to the left. There is also evidence of pulmonary interstitial emphysema in the right lung.
CXR of pulmonary interstitial emphysema
CXR AP shows a branching bubbly appearance to the right lung.
CXR of pulmonary interstitial emphysema
CXR AP shows a branching bubbly appearance to the right lung and a large amount of air in the right pleural space.
CXR of pulmonary interstitial emphysema
CXR AP shows air in the pulmonary interstitium bilaterally, in a branching pattern radiating outwards from the hila.
AXR of pneumoperitoneum in a patient with respiratory distress syndrome
CXR AP shows a bubbly branching appearance to the right lower lobe and overall increased lucency throughout the entire abdomen.

Gross Pathology Cases of Pulmonary Interstitial Emphysema

Gross pathology image of pulmonary interstitial emphysema
Gross pathological image of the right lung shows bubbles of air throughout the pulmonary interstitium of the lung.
Pathology image of pulmonary interstitial emphysema
Gross pathological sectioned image shows air bubbles throughout the pulmonary interstitium.