Cerebral Air Embolism Occurring During Percutaneous Endoscopic Gastrostomy.

Air embolism is a rare but potentially fatal complication of gastrointestinal endoscopic procedures, primarily affecting the pulmonary circulation. Systemic air embolism, especially with cerebral involvement, is exceedingly uncommon. We report a case of cerebral air embolism that occurred during percutaneous endoscopic gastrostomy (PEG) using the pull method in a 65-year-old man with dysphagia due to progressive supranuclear palsy with frontotemporal dementia. Immediately after guidewire externalization, the patient experienced sudden respiratory arrest and hemodynamic collapse, necessitating cardiopulmonary resuscitation. Although aspiration was initially suspected, chest radiography showed no abnormalities. As spontaneous respiration did not recover, brain CT was performed, revealing multiple intracranial air densities consistent with cerebral air embolism. Transthoracic echocardiography showed no evidence of a right-to-left shunt. The patient received hyperbaric oxygen therapy; however, impaired consciousness persisted, likely due to hypoxic brain injury. This case suggests that excessive air insufflation and vascular injury during PEG may cause systemic air embolism even in the absence of an identifiable intracardiac shunt. Clinicians should consider this rare but life-threatening complication when unexplained cardiopulmonary collapse occurs during PEG.