An unusual case of severe therapy-resistant hypertension in a newborn.

Hypertension can occur in up to 2% of neonates, and the spectrum of potential causes is broad. Prompt and thorough evaluation with a main focus on kidney disease is key for appropriate therapy. Here we describe a 2-day-old neonate with feeding intolerance and elevated blood pressure readings. Within 24 hours after birth, the infant's blood pressure increased significantly, with sustained mean arterial pressure >85. Renal Doppler ultrasound showed decreased venous blood flow in the right kidney with an abnormal Doppler wave form suggestive of unilateral renal venous thrombosis. Despite aggressive antihypertensive therapy including hydralazine and enalaprilat, hypertension remained sustained. On day-of-life 4, the infant developed clinical signs of hypertensive encephalopathy and significant cardiac dysfunction. A renal angiography showed complete, likely thrombotic occlusion of the right renal artery. Renal MAG3 imaging showed minimal function of the affected kidney, and a nephrectomy secondary to medically uncontrollable hypertension and worsening cardiac dysfunction was performed. The child is developing normally in all aspects on follow-up evaluations at 6 months and 1 year of age. Reevaluation of the working diagnosis in neonates with hypertension can be necessary to optimize the outcome. The overall prognosis can be excellent even in newborns with profound cardiac and neurologic involvement.