Retroperitoneal air dissection associated with mechanical ventilation.

The radiologic patterns, etiology, and possible consequences of gas dissection into the retroperitoneal space from pulmonary sources are reviewed in three patients requiring mechanical ventilation. Airway disruption appears to be related to peak airway pressures, underlying pulmonary disease, and the patient's hemodynamic condition and may cause different forms of interstitial emphysema and air embolization, which may lead to severe respiratory or circulatory dysfunction. Gas migration to the retroperitoneum and, secondarily, into the peritoneal cavity should be considered in the differential diagnosis of free intra-abdominal gas.