Persistent pulmonary hypertension and infantile hypertrophic pyloric stenosis in a neonate: Reduced nitric oxide levels could be a common etiological factor

Nitric oxide (NO) is an important mediator of biological functions. It is a potent vasodilator and has an effect on smooth muscle relaxation and proliferation. Absence or shortage of NO plays a role in the pathogenesis of persistent pulmonary hypertension and hypertrophic pyloric stenosis. A 3.2 kg male, full term baby, delivered through vaginal route in hospital settings presented with curdy white and non-bilious vomiting following feeds on 22 nd day of life. Baby had a history of neonatal intensive care unit admission for 4 days for respiratory distress due to meconium stained liquor. 2D echocardiography revealed pulmonary hypertension. On 22 nd day of life when vomiting began, baby was vigorous, irritable but examined well. Since, these two conditions occurred simultaneously in the same baby hence postulation that NO might have some role in both diseases.