[Efficacy of nifedipine on refractory hypoxemia associated with diaphragmatic hernia in the newborn infant. Apropos of a case].

A 3,200 g birth weight, 38-week gestational age neonate developed very severe persistent pulmonary hypertension following surgical repair of a left diaphragmatic hernia. Despite administration of dopamine, dobutamine, and tolazoline, a significant alveolar-arterial oxygen difference (660 mmHg) was found at age 41 hours. Nifedipine was then administered sublingually in a dose of 1 mg/kg and produced an immediate and dramatic improvement in the right radial artery pO2 that was sustained despite persistence of the right-to-left shunt. We discuss the mode of action of this vasodilating agent that, when added to major therapeutic agents, proved capable of completely reversing a hazardous neonatal situation.