What is this study about? We are studying whether Shenfu Injection (a traditional Chinese herbal medicine) can help improve blood vessel health in patients with septic shock-a severe complication of infections that can damage blood vessels and organs. Specifically, we want to see if this treatment makes the carotid artery (a major neck blood vessel) more flexible and resilient, which may support recovery.

Who can join? Adults (18 years or older) diagnosed with septic shock by their doctors. Patients whose doctors plan to use Shenfu Injection as part of their treatment. Patients who agree to participate and sign a consent form. Who cannot join? Patients with severe heart conditions, advanced organ failure, or major neck artery disease.

Pregnant or breastfeeding women. Those unable to complete the study procedures. What will happen during the study?

Safe and Pain-Free Tests:

Ultrasound scans: A non-invasive imaging method will be used to measure the flexibility and blood flow of your neck artery.

Advanced imaging technology: A special ultrasound technique (called speckle tracking) will take detailed pictures of your artery's movement during heartbeat cycles.

Timing of Tests:

Scans will be done before receiving Shenfu Injection and 1, 2, 3 hours after the injection, plus 1 hour after treatment ends.

Other Data Collection:

Blood tests to check inflammation and organ function. Recording your health status (e.g., blood pressure, heart rate) and recovery progress (e.g., time in the Intensive Care Unit (ICU), survival rates).

What are the benefits and risks? Benefits: This study may help doctors better understand how Shenfu Injection works and improve future care for septic shock patients.

Risks: The ultrasound scans are routine, safe, and painless. There is no extra risk beyond standard hospital care.

Your Rights and Safety Voluntary Participation: You can withdraw at any time without affecting your treatment.

Ethical Approval: This study is reviewed and approved by the hospital's ethics committee.

Privacy: Your personal information and test results will be kept confidential.

Inclusion Criteria

• Age ≥ 18 years.
• Diagnosis of sepsis or septic shock in the acute phase, as defined by the -Sepsis-3 criteria (confirmed infection with Sequential Organ Failure Assessment [SOFA] score ≥ 2 points above baseline).
• Voluntary participation with written informed consent provided by the patient or legally authorized representative.

Exclusion Criteria

• Severe carotid atherosclerosis (e.g., carotid Intima-Media Thickness (IMT)>1.2 mm or confirmed plaque formation) diagnosed by prior imaging.
• Significant cardiovascular comorbidities that may confound hemodynamic assessments, including:
• Severe cardiomyopathy (e.g., ejection fraction <30%).
• Uncontrolled arrhythmias (e.g., ventricular tachycardia, atrial fibrillation with rapid ventricular response).
• Congenital heart disease with hemodynamic instability.
• Active hepatic or renal insufficiency (e.g., Child-Pugh class C, dialysis dependence) or advanced systemic diseases (e.g., metastatic malignancy, terminal illness).
• Poor ultrasound image quality precluding reliable speckle tracking analysis (e.g., inadequate acoustic window, motion artifacts).
• Pregnancy or lactation (due to potential hormonal influences on vascular physiology).
• Withdrawal from the study or inability to complete follow-up assessments (e.g., non-compliance, transfer to another facility).