S5479 Impact of Methylene Blue on Mean Arterial Pressure and Vasopressor Requirement in Cirrhotic Patients With Vasodilatory Shock: A Case Series

Introduction: Cirrhotic patients with vasodilatory shock often fail to respond to standard vasopressor therapies due to the complex interplay of nitric oxide (NO) dysregulation, termed the “NO paradox.” While deficient NO within the liver exacerbates portal hypertension, excessive NO in systemic circulation leads to profound vasodilation and hypotension. Methylene blue (MB), a nitric oxide synthase and guanylate cyclase inhibitor, has shown promise in managing vasodilatory shock. The recommended dose of methylene blue is 1–3 mg/kg, which has been shown in other contexts, such as septic and vasoplegic shock, to improve hemodynamic parameters, reduce mortality, and shorten ICU stays. However, its role in cirrhotic patients remains underexplored. Case Description/Methods: This case series retrospectively analyzed 3 ICU patients with liver cirrhosis who received MB for vasodilatory shock. Clinical data, including demographics, etiology of cirrhosis, MAP, vasopressor requirements, and lactate levels, were collected before and after MB administration. Outcomes included changes in MAP and vasopressor requirements at 1, 6, and 24 hours post-MB. All 3 patients demonstrated an improvement in mean arterial pressure (MAP) within 6 hours of methylene blue (MB) administration, with an average increase from 58.7 mmHg pre-MB to 69.7 mmHg at 6 hours. However, this improvement was not sustained in 2 out of 3 patients by 24 hours, with MAP returning close to baseline levels. Vasopressor requirements were reduced in 2 patients, with one patient achieving complete discontinuation of vasopressors within 24 hours. The administered MB dosage was 1 mg/kg in all cases, which may have contributed to the transient nature of the observed effects. These findings suggest a potential short-term benefit of MB in improving hemodynamic stability in cirrhotic patients with vasodilatory shock, though its effects may not be durable in all cases. Discussion: The results suggest that methylene blue provides initial hemodynamic stabilization, but the 1 mg/kg dose used may be insufficient for sustained effects. Higher or repeated doses within the 1–3 mg/kg range could improve efficacy. Future studies should explore optimal dosing strategies, safety, and long-term outcomes. Methylene blue shows promise as an adjunct therapy in refractory vasodilatory shock, addressing a critical gap in cirrhotic patient management.