Air Everywhere without Bowel Injury

Dear Editor, Blunt traumatic injury to the chest commonly causes rib fractures, pneumothorax, hemothorax, pneumomediastinum, and lung parenchymal injuries, but the concurrent presence of pneumothorax, pneumomediastinum, pneumoperitoneum, pneumoretroperitoneum, pneumoscrotum, and extensive myofascial emphysema is uncommon in the absence of hollow visceral perforation.1 A 51-year-old male presented to the emergency with alleged history of bull horn injury over the back. On clinical examination, respiratory rate was 28/min, SpO2: 98% on O2 (10 L/min). Air entry was absent on the right side. External subcutaneous emphysema and crept were seen extending from the periorbital region to the scrotum and bilateral knee, no blood at the urethral meatus. On abdominal examination, it was soft and non-tender, no rigidity or guarding was present. Contrast-enhanced computed tomography was done which showed a fracture of the right third rib, pneumomediastinum, and pneumothorax. Extensive myofascial emphysema was seen extending from the chest wall to the bilateral thighs. There were gross pneumoretroperitoneum, pneumoperitoneum, and pneumoscrotum with a breach in the myofascial plane in the right lumbar region Figure 1. No evidence of hollow or solid visceral injury was found. The patient was managed conservatively and discharged in good condition. Multiple theories have been proposed in the past to explain the leakage of air in the multiple body compartments, mainly focusing on the transdiaphragmatic route.2,3 In general, the intra-abdominal pressure is more than intrathoracic pressure. When the intrathoracic pressure increases the air from ruptured alveoli traverse along peribronchovascular fascial sheath at the lung roots and enters the mediastinum. This is also known as Macklin effect.4 The mediastinal air may traverse directly through the diaphragmatic hiatus into the perinephric space causing pneumoretroperitoneum, as seen in our case. Further, the air may extend into the scrotum along the spermatic fascia and the inguinal canal, as noted in this case Figure 2. The mediastinum has a communication with the retroperitoneum at the sternocostal attachment of the diaphragm which then further continues with the flanks into the pelvis. This could also be another possible explanation for the air in the pelvis in our case. Although surgery was not required in this case and the patient managed conservatively, strict vital monitoring is the foremost thing in such patients to look for any signs of deterioration and anticipate the emergency.5 Therefore, awareness of this entity and pathophysiological mechanism of multi-compartmental air not being always associated with hollow viscous injury is important in emergency.Figure 1: (a) Computed tomography (CT) scanogram showing extensive myofascial emphysema, pneumoscrotum, and chest tube on the right side. (b) Coronal CT image also revealing extensive myofascial emphysema with right pneumothorax and pneumomediastinum. (c and d) Axial CT images showing pneumoretroperitoneum, pneumoperitoneum, and pneumoscrotumFigure 2: Mechanism of multi-compartmental air leakage in the absence of hollow viscous injuryDeclaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.