Macklin effect (pulmonary interstitial emphysema and pneumomediastinum)

The Macklin effect describes one of the pathophysiological processes of pneumomediastinum in blunt chest trauma. The Macklin effect accounts for ~40% of severe blunt traumatic pneumomediastinum. Exclusion of tracheobronchial and esophageal causes of pneumomediastinum is mandatory to exclude concomitant injury.

Pathology

The proposed mechanism is an alveolar rupture with air dissecting along peribronchovascular interstitial sheaths, interlobular septa, and the visceral pleura into the mediastinum .

Radiographic features

CT

Pulmonary interstitial emphysema with air tracking along the peribronchovascular sheaths towards the hilum and associated pneumomediastinum.

History and etymology

The pathophysiologic process was first proposed by C C Macklin in 1939 .