Inhaled Nitric Oxide (iNO)

Nitric oxide (NO) is a reactive colorless gas which if present in alveoli diffuses into the adjacent pulmonary vascular smooth muscle causing local vasodilatation by activating cGMP (cyclic Guanine mono-phosphate). NO spill over into the bloodstream is almost instantaneously inactivated through binding to sulfhydryl groups of the hemoglobin molecule and nitrites thereby preventing systemic vasodilatation, and establishing inhaled nitric oxide (iNO) as a specific pulmonary vasodilator. iNO has been shown to lower pulmonary vascular resistance (PVR) and/or improve ventilation-perfusion matching in a wide range of clinical scenarios.