Inhaled nitric oxide as a salvage therapy for refractory hypoxemia in the post-transplantation period of hepatopulmonary syndrome: An explorative report of three cases

Liver transplantation (LT) is the only effective treatment for hepatopulmonary syndrome (HPS). Moreover, perioperative refractory hypoxemia (pRH) is a prevalent life-threatening condition and has extremely limited treatment options. Here, we report three patients with HPS who experienced pRH after LT and were consecutively treated with different salvage therapies, ephedrine inhalation, intravenous use of methylene blue with nitric oxide (NO) inhalation, and NO inhalation alone. The results showed that unresolved severe hypoxia may induce fatal morbidity such as early biliary leakage and acute kidney injury. Early initiation of NO inhalation, rather than ephedrine, can significantly improve oxygenation in patients with pRH and may help prevent hypoxia-related complications. Therefore, based on the response to these exploratory salvage treatments, we further demonstrate the unique ventilation-perfusion mismatch pathophysiology in specific lung regions during pRH in HPS. We propose that early inhalation of NO is an important treatment option to rescue severe hypoxia in patients with HPS during the perioperative period of LT.