Efficacy and Safety of Methylene Blue in the Treatment of Severe Septic Shock

Inclusion Criteria: 1. Age ≥ 18 years. 2. Meets the Sepsis 3.0 criteria for septic shock: patients with infection who, despite adequate fluid resuscitation, require vasopressor therapy to maintain a mean arterial pressure (MAP) of ≥ 65 mmHg and have a blood lactate concentration \> 2 mmol/L. 3. Diagnosed with septic shock and started on norepinephrine within 24 hours. 4. Requires a norepinephrine dose of ≥ 0.1 μg/kg/min to maintain a MAP of ≥ 65 mmHg. Exclusion Criteria: 1. Pregnant or breastfeeding women. 2. Individuals allergic to methylene blue or any components of the methylene blue injection. 3. Individuals with a personal or family history of glucose-6-phosphate dehydrogenase (G6PD) deficiency. 4. Patients with an expected survival time of less than 48 hours. 5. Patients who have been on norepinephrine for more than 24 hours.