Pulmonary interstitial emphysema: A rare complication in adults (Report of two cases).

Pulmonary interstitial emphysema (PIE) is a rare and potentially life-threatening complication in mechanically ventilated adults. While extensively described in neonates, its occurrence in adults remains exceptional. We report two cases of PIE in polytrauma patients requiring invasive ventilation after severe road traffic accidents. Both cases are remarkable for early detection on CT within hours after intubation and the occurrence of PIE despite moderate ventilator settings. Initial CT imaging revealed characteristic findings of PIE, including air tracking along the interlobular septa and pulmonary vessels. To our knowledge, reports of PIE in the context of acute trauma, with rapid onset and confirmation by early CT, are scarce. Both patients developed neurological complications, including post-traumatic meningitis, and required prolonged intensive care with tracheostomy and structured ventilator weaning. These observations emphasize the importance of considering PIE in ventilated patients with unexplained pneumomediastinum or subcutaneous emphysema, particularly when conventional radiography is inconclusive. This report highlights the critical role of early radiological recognition of PIE and ventilator adjustment in preventing life-threatening complications.