Nitric oxide in the management of persistent pulmonary hypertension of the newborn--an unusual cause of failure.

A diagnosis of persistent pulmonary hypertension of the newborn should be reviewed if there is a failure to respond to appropriate treatment. We report a case in which both conventional therapy and inhaled nitric oxide failed to break the cycle of right-to-left shunting. Reassessment revealed a massive pulmonary arteriovenous malformation for which surgery was successfully performed in the neonatal period.