Complication of mechanical ventilation in patients with acute lung injuries.
Results from increased airway pressures with tension pneumothorax, pneomomediastinum and less common pneumoperitoneum.
Air entering alveoli may become distended and rupture releasing air into collateral spaces.
Air rupturing through the alveoli migrates along perivascular sheaths to the mediastinum leading to mediastinal emphysema, and subsequently can rupture through the mediastinal pleura and cause a pneumothorax.
Air can dissect from the alveoli eventually retroperitoneally into the peritoneal cavity and cause a pneumoperitoneum.