Management of severe pulmonary hypertension in an infant with obstructed total anomalous pulmonary venous return using magnesium sulfate.

Severe hypoxemia and pulmonary hypertension occurred in an infant with total anomalous pulmonary venous return. Though under hyperventilation with high fractional inspired oxygen and prostaglandin E1, hypoxemia remained intractable. Magnesium sulfate was used in view of its vasodilating effect. Significant clinical improvement was observed without causing systemic hypotension and the mechanism is discussed.