(1182) Inhaled NO Improved Severe Hepatopulmonary Syndrome With Sepsis

Introduction: We documented a case involving a 45-year-old male patient who was diagnosed with post-operative sepsis and hepatopulmonary syndrome (HPS) due to hepatitis B cirrhosis. Treatment with inhaled nitric oxide (iNO) at 30 ppm improved oxygen saturation over 36 hours. After discontinuation of iNO, exhaled nitric oxide (eNO) levels significantly decreased to 8 ppb(initiation of 30 ppb).

Description: We presented a case of a 45-year-old male with a history of hepatitis B cirrhosis who underwent emergency surgery for gallbladder perforation. Following the procedure, the patient developed severe hypoxemia and was diagnosed with HPS. The patient's initial arterial blood gas analysis showed severe hypoxemia with a P/F ratio of 92 mmHg, indicating significant impairment of gas exchange. Imaging studies suggested the presence of intrapulmonary vascular dilations (IPVDs) or shunt, which is characteristic of HPS. Additionally, hemodynamic monitoring revealed relatively preserved cardiac function.
After 36 hours of 30ppm-iNO therapy, the patient's oxygen saturation improved significantly. Electrical impedance tomography (EIT) indicated improved ventilation-perfusion matching following iNO therapy.
Upon discontinuation of iNO, the patient's eNO levels decreased significantly, suggesting a positive response to iNO therapy.

Discussion: Key characteristics of HPS encompass compromised gas exchange due to IPVDs and right-to-left shunting. Diagnostic criteria: (1) liver disease; (2) IPVDs and/or shunting; (3) alveolar-arterial oxygen gradient [P(A-a)O2] ≥ 15 mmHg. In this instance, the patient met all three criteria, with cardiac contrast echocardiography confirming the presence of the shunt as the gold standard.
Studies have demonstrated elevated levels of eNO in HPS patients, implicating heightened activity of pulmonary endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in excessive NO production within the lungs, thereby inducing aberrant pulmonary vasodilation and HPS progression. Notably, elevated eNO levels coincided with severe hypoxemia, and EIT indicated the presence of an intrapulmonary shunt. Following treatment with iNO substantial improvements in ventilation-perfusion matching and oxygenation were observed, accompanied by a significant decrease in eNO levels.