The Macklin Effect: An Underestimated Cause of Pneumomediastinum.

The Macklin effect is a rare but potentially serious complication of pneumomediastinum, caused by the dissemination of air from the lungs into the subcutaneous tissue and mediastinum after severe chest trauma or invasive manipulation. Early recognition is crucial for proper management of the patient. A 33-year-old male skidded while riding a motorcycle, lost control of the vehicle, and crashed into a utility pole with a thoracic contusion. He was admitted to the hospital; a computed tomography (CT) of the chest and abdomen was requested, which ruled out the presence of fractures and showed air in the mediastinum and subcutaneous cellular tissue, with features suggestive of the Macklin phenomenon. After 72 hours of inpatient monitoring, the patient was discharged to the general surgery outpatient clinic. The Macklin phenomenon occurs as a result of airway rupture due to negative pressure caused by trauma or invasive mechanical ventilation. Risk factors include a higher prevalence in young males, a slender stature and above-average height, and an age range of 12 to 35 years. Early detection of the Macklin phenomenon is crucial to recognize and prevent further complications. This case demonstrated the importance of considering the Macklin effect as a cause of pneumomediastinum in patients with severe chest trauma. Diagnostic imaging plays a key role in confirming the diagnosis and planning treatment.