Pathophysiology and Management of Neurogenic Pulmonary Edema in Patients with Acute Severe Brain Injury

Acute brain injury (ABI) consists of any acquired insult to the brain and is a significant cause of morbidity and mortality worldwide. Approximately 20% to 30% of patients with ABI develop a lung injury called neurogenic pulmonary edema (NPE), and its development often results in poor outcomes. This article provides a narrative review of the evidence regarding proposed mechanisms of injury, diagnosis, and treatment of NPE in the critical care setting. PubMed and Ovid databases were searched for observational or prospective studies relevant to the diagnosis and treatment of NPE. Overall, studies showed that although the specific mechanisms responsible for NPE remain uncertain, putative mechanisms include vaso- and venoconstriction, catecholamine release with resultant pulmonary vasoconstriction called the "blast injury theory," increased vagal tone, and increased capillary permeability. Diagnosis involves identifying signs of pulmonary edema in patients who experienced a neurologic insult. Management strategies aim to address both brain and lung injury, and treatment modalities appear to work best when balanced toward maintaining a normal physiologic state. In summary, NPE is an often underdiagnosed but important sequela of ABI, which may result in additional long-term morbidity. It is therefore an important entity for providers to recognize and tailor their clinical approach toward.