Abstract
BACKGROUND: Vasoplegia is a life-threatening intraoperative condition. Methylene blue (MB), a potent inhibitor of nitric oxide (NO) synthase and soluble guanylyl cyclase (sGC), can treat vasoplegia but may antagonize pulmonary arterial hypertension (PAH) drugs that enhance the NO-sGC-cyclic guanosine monophosphate (cGMP) pathway. Although reports on the use of MB for vasoplegia during liver transplantation (LT) have often been published, managing vasoplegia during LT in a patient with cardiopulmonary disease, including portopulmonary hypertension (PoPH) - a subgroup of PAH - with intracardiac shunt, is challenging and has not been reported. CASE PRESENTATION: We report a 57-year-old woman with PoPH, on anti-PAH selexipag with concomitant atrial septal defect (ASD) undergoing deceased donor LT. After portal reperfusion, she developed refractory hypotension, in which mean arterial blood pressure (ABP) was less than 50 mmHg and the cardiac index (CI) was maintained at 5.0 L·min(-1)·m(-2), despite high dose of vasopressin of 4 unit·h(-1). Diagnosed with vasoplegia, she received 100 mg of MB. Mean ABP promptly improved from 45 to above 60 mmHg, systolic ABP from around 60 to above 95 mmHg, allowing immediate reduction of vasopressin to 0.5 unit·h(-1). She was transferred to ICU with stable hemodynamics. CONCLUSION: MB can be lifesaving for intraoperative vasoplegia even in patients with PoPH on PAH drug therapy with an ASD, though potential drug interactions with anti-PAH drugs warrant caution.