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

28-day survival rate of enrolled patients

Our primary endpoint is the 28-day survival rate of enrolled patients: All enrolled patients will be followed from the time of randomization until 28 days post-enrollment, recording the survival status on the 28th day after enrollment. If a patient dies within 28 days post-enrollment, the number of survival days will be recorded. Note: 1. Cases where the family requests discharge to home for end-of-life care and the patient subsequently dies will be counted as death cases. 2. Cases where the family requests discharge for non-medical reasons such as financial constraints and no further treatment is sought will be counted as dropout cases.

The duration and dosage of norepinephrine use

The duration of norepinephrine use：The time from the start of norepinephrine (NE) administration after sepsis diagnosis until its discontinuation. The definition of discontinuation: NE must be stopped for ≥2 hours; if NE is stopped for \<2 hours, it is not considered discontinued. If NE is re-administered after being stopped for more than 2 hours, it is still considered discontinued. The dosage of norepinephrine use：the total dose of NE used within 72 hours after the patient is enrolled in the study.

The duration of mechanical ventilation

The number of days without mechanical ventilation within 28 days post-enrollment. Note: Only full days without mechanical ventilation can be counted as one day.

The duration of ICU stay

ICU length of stay: the number of days in the ICU starting from the time of patient enrollment in the study. Note: Some patients may have multiple ICU admissions; only the ICU stay duration after the current enrollment is recorded.

The duration of overall hospital stay

The duration of overall hospital stay: the total number of days hospitalized starting from the time of patient enrollment in the study. Note: Days hospitalized prior to enrollment are not included.