The ductus arteriosus is kept open by infusion of PGE₁. Both PGE₁ and PGE₂ are produced endogenously in the ductus and metabolized in the lungs. Among the endogenous prostaglandins, PGE₂ is the most important. Postnatally, levels fall dramatically secondary to increased metabolism, resulting from the increase in pulmonary blood flow. A prostaglandin infusion will delay the natural closure of the ductus and improve systemic arterial perfusion and oxygenation. Less acidosis will also be seen in arterial blood gases compared to those obtained prior to PGE₁ infusion administration. In the case of an IAA, circulation to the lower body is completely dependent on the patency of the ductus; therefore, PGE₁ must be continuously infused to keep the infant alive. Of note, the PGE₁ infusion has a relatively long half-life; its inadvertent discontinuation will not acutely cause ductal closure, but it should be maintained until surgical repair is complete.

References

• Burbano-Vera N, Zaleski KL, Latham GJ, et al. Perioperative and anesthetic considerations of interrupted aortic arch. Semin Cardiothorac Vasc Anesth. 2018;22:270-277.
• Kliegman RM, St. Geme JW, Blum NG et al. Acyanotic congenital heart disease: obstructive lesions. In: Kliegman RM, St. Geme JW eds. Nelson Textbook of Pediatrics. 22nd ed. Elsevier; 2024:2787-2796.
• Ron HA, Crowley TB, Liu Y, et al. Improved outcomes in patients with 22q11.2 deletion syndrome and diagnosis of interrupted aortic arch prior to birth hospital discharge, a retrospective study. Genes. 2023;14:1-11.