How Do We Safely Use Inhaled Nitric Oxide?

* Abbreviations: iNO = : inhaled nitric oxide • ECMO = : extracorporeal membrane oxygenation The physiologic effects of inhaled nitric oxide (iNO) were first presented in 1992.1 ,2 Although the neonatal community has embraced iNO as a selective pulmonary vasodilator that reduces the use of (not need for) extracorporeal membrane oxygenation (ECMO), the drug (at the time that this commentary was written) is not approved for clinical use. Why? To approve a therapy, the Food and Drug Administration usually requires that two separate clinical trials show that it improves a specific outcome without increasing the risk for adverse outcomes. In addition, the improved outcome should impact health, not just physiology. Improvements in physiology (improved oxygenation) do not always translate to improvements in health (eg, increased Pao 2 in premature neonates increases the risk for retinopathy). Studies establish that iNO improves oxygenation3–5 and reduces the use of ECMO.4 ,6 Unfortunately, these outcome measures are not surrogate markers for improved health. If avoiding ECMO … Address correspondence to Reese H. Clark, MD, Pediatrix Medical Group, 1455 North Park Dr, Fort Lauderdale, FL 33326. E-mail:reese_clark{at}mail.pediatrix.com