Delayed-onset Neurogenic Pulmonary Edema Following a Ruptured Posterior Communicating Artery Aneurysm: A Case Report.

Neurogenic pulmonary edema is a rare but severe complication of acute central nervous system injury, such as subarachnoid hemorrhage, typically presenting with immediate onset. This report describes an uncommon case of delayed-onset neurogenic pulmonary edema following subarachnoid hemorrhage. A 68-year-old man with subarachnoid hemorrhage, caused by a ruptured left posterior communicating artery aneurysm, developed tachypnea and hypoxemia with bilateral pulmonary infiltrates 96 hours after symptom onset. Echocardiography was normal, ruling out cardiogenic causes, and neurogenic pulmonary edema was diagnosed. The patient improved rapidly with fluid restriction and diuretic therapy, and subsequently underwent successful aneurysm coil embolization. Neurogenic pulmonary edema is thought to result from an excessive sympathetic activation leading to pulmonary vasoconstriction, increased capillary pressure, and endothelial injury. Delayed cases may involve secondary sympathetic surges due to intracranial pressure fluctuations, vasospasm, or inflammatory injury. This case highlights the need for clinicians to consider delayed neurogenic pulmonary edema when respiratory deterioration occurs several days after subarachnoid hemorrhage to ensure timely diagnosis and life-saving management.