Favorable response of Eisenmenger syndrome to inhaled nitric oxide during pregnancy

OBJECTIVE: Our goat was to evaluate the effectiveness of therapy with a spe cific pulmonary vasodilator, nitric oxide, in a woman with Eisenmenger synd rome during pregnancy. STUDY DESIGN: Eisenmenger syndrome consists of a congenital communication b etween the systemic and pulmonary circulation with secondary pulmonary hype rtension causing reversal of flow through the shunt. Maternal morbidity is approximately 50% with the greatest risk of death being in the peripartum p eriod. Pharmacologic therapy to relieve worsening pulmonary hypertension is confounded by the undesired effects of vasodilators on the systemic circul ation. Therapy with a specific pulmonary vasodilator, nitric oxide, was att empted. RESULTS: A 27-year-old woman with Eisenmenger syndrome at 36 weeks' gestati on was treated with inhaled nitric oxide during the second stage of labor a nd the postpartum period when she experienced progressive refractory hypoxe mia. Administration of nitric oxide was followed by improved oxygenation an d lowering of pulmonary artery pressures. A brief episode of methemoglobine mia responded to lowering of the nitric oxide concentration and administrat ion of intravenous methylene blue. Nitric oxide was discontinued after 48 h ours. The patient died 2 days later despite continued vasodilator therapy i ncluding intra-pulmonary artery prostacyclin. CONCLUSION: Inhaled nitric oxide can be used to correct the hypoxemia of Ei senmenger syndrome. Nitric oxide inhalation is easily performed, and pulmon ary vasodilatory effects commence within minutes after administration.