Pulmonary edema after resection of a fourth ventricle tumor: possible evidence for a medulla-mediated mechanism.

A well-recognized fact is that some patients may have development of pulmonary edema in association with disorders of the central nervous system. The origin of this phenomenon, known as neurogenic pulmonary edema, is unclear but may result, in part, from select pulmonary venoconstriction modulated by autonomic outflow from the medulla oblongata. We describe a 21-year-old man who had development of pulmonary edema in association with surgical resection of a brain tumor that was close to the medulla. Other than the possibility of medullary dysfunction, which could have occurred after surgical manipulation, no other risk factor for pulmonary edema was identified. Of note, the patient's blood pressure remained normal throughout the perioperative period, and no fluid overload or primary cardiac dysfunction was evident. This case supports the theory that the medulla is an important anatomic site of origin for neurogenic pulmonary edema and that alterations in medullary function can induce pulmonary edema in humans, independent of systemic hypertension.