1. Eligibility Criteria (1) Mild to moderate sepsis as defined by the △SOFA score; (2) Admission to ICU \<24 hours; (3) Serum total bile acid concentration TBA ≥10μmol/L, total bilirubin concentration TBiL ≥17.1 μmol/L; (4) Patients with suspected or confirmed infection as the main cause.
2. Exclusion Criteria (1) Age \>85 years or \<18 years; (2) Patients contraindicated for mecobalamin treatment, allergic to ceftriaxone sodium, or other contraindications; (3) Existence of a potential disease with a life expectancy of \<1 year; (4) Patients with non-infectious causes such as burns, trauma, chemical poisoning; (5) Withdrawal of life support or anticipated life-threatening condition within 48 hours; (6) History of autoimmune diseases, tumors, hepatobiliary diseases, diabetes, metabolic genetic diseases; (7) Vitamin B deficiency, malnutrition history; (8) Re-admission to ICU within one year; (9) Relatives or guardians unwilling to participate in the study; (10) Pregnancy.
3. Withdrawal Criteria (1) Adverse reactions related to mecobalamin or ceftriaxone sodium treatment; (2) Rapid progression of disease requiring treatment adjustment; (3) Other life-threatening reasons as decided by the clinician to stop the trial; (4) Patient or guardian request to withdraw from the trial.
4. Termination Criteria (1) Severe or intolerable adverse events (e.g., severe liver and kidney dysfunction), necessitating withdrawal from the trial as judged by the researchers; (2) Decision by the patient and family to withdraw from the study at any stage; (3) Discontinuation of participation in the study as deemed necessary by the attending physician based on the patient's condition.
5. Study Content 5.1 Screening Period Within 24 hours before enrollment, perform blood routine, liver and kidney function tests, and interviews. Select sputum, blood, and other fluid samples based on potential infection sites for smear and Gram staining microscopy. Concurrently conduct blood culture and drug sensitivity tests to assess the most likely pathogens causing infection. Randomly assign patients into either the placebo group or the ceftriaxone group following the principle of random controlled trials, done by a computer system (like drawing lots) at a 1:1 ratio. The process is uncontrollable by doctors or others. All trial drug packages look the same and can only be identified by a unique trial identifier. Group assignment and drug numbering are managed by a designated person. The appearance of the drug boxes for both groups is identical, and the attending physicians and patients are unaware of whether the drugs in the numbered boxes are placebo or therapeutic. The bedside nurses are responsible for administering the numbered drugs according to the plan, thus ensuring blinding of the trial participants and all research center staff to ceftriaxone, mecobalamin, or placebo.
5.2 Intervention Period Both groups receive standard sepsis treatment and care (decided by the attending physician). Additional treatments are as follows: 1) Control group (n=20): intravenous saline drip/oral placebo tablets; 2) Mecobalamin + ceftriaxone sodium group (n=20): intravenous drip of ceftriaxone sodium 1g per dose, twice daily (for 14 consecutive days), and mecobalamin injection 1mg per dose, once daily (on days 1, 2, 3, 5, 7, 9, 11, 13), with at least a half-hour interval between medications. From day 15 to 28, take mecobalamin tablets orally, 1mg per dose, three times a day.
5.3 Follow-up Period 5.3.1 Main Indicators (1) General data: Admission basic materials (name, gender, date of birth, height, actual weight, etc.), ICU admission details (time of joining the group, APACHEII score, SOFA score, Glasgow score, main diagnosis, medical history, etc.), pre-enrollment treatment and medication records. (2) On days 1, 3, 7, 14, and 28 or before transfer from ICU: organ failure (SOFA score), ALT, AST, total bilirubin, direct bilirubin, indirect bilirubin, bile acids, blood ammonia, coagulation function, blood gases, vasoactive drugs, kidney function, serum lactate. (3) Liver ultrasound imaging on days 1, 7, 14, or before ICU transfer.
Note: Organ failure is measured by the Sequential Organ Failure Assessment (SOFA) score, grading the function of six organ systems based on blood pressure and vasoactive drug needs, oxygenation, platelet count, serum creatinine, and bilirubin levels, as well as the Glasgow Coma Scale score. The severity of illness is measured by the Acute Physiology and Chronic Health Evaluation (APACHE) II, ranging from 0 to 71, with higher scores indicating a higher risk of death.
6. Evaluation Indicators/Study Endpoints 6.1 Primary Observation Endpoint Improvement in liver function by 28 days or at discharge/death: Total bilirubin reduced to ≤17.1μmol/L and bile acids \<10μmol/L.
6.2 Secondary Observation Endpoints (1) 28-day mortality rate; (2) ICU and hospital stay duration; (3) Number of days without organ dysfunction in 28 days; (4) Changes in serum markers related to cell pyroptosis and tissue necrosis, such as interleukins-1β, 1α, LDH, etc.
7. Visit Arrangement and Data Collection During the Study (1) General data: Admission basic materials (name, gender, date of birth, height, actual weight, etc.), ICU admission details (time of joining the group, APACHEII score, SOFA score, Glasgow score, main diagnosis, medical history, etc.), pre-enrollment treatment and medication records. (2) On days 1, 3, 7, 14, and 28 or before transfer from ICU: organ failure (SOFA score), ALT, AST, total bilirubin, direct bilirubin, indirect bilirubin, bile acids, blood ammonia, coagulation function, blood gases, vasoactive drugs, kidney function, serum lactate. (3) Liver ultrasound imaging on days 1, 7, 14, or before ICU transfer.
