In this study, midazolam was used as a control to investigate the effect of remazolam besylate combined with remifentanil on analgesia and sedation in patients with mechanical ventilation of sepsis on the prognosis of patients, and to provide evidence for the safe application of remazolam besylate in patients with sepsis.

Inclusion Criteria:

1. Mechanical ventilation patients with sepsis who are expected to stay in ICU for ≥48h;
2. The condition was allowed to remain in shallow sedation (RASS-2 ~0);
3. Obtain informed consent from patients or family members

Exclusion Criteria:

1. pregnancy or breastfeeding;
2. General anesthesia surgery within 48 hours;
3. Severe, pre-existing parenchymatous liver disease with clinically significant portal hypertension, Child-Pugh grade C cirrhosis or acute liver failure;
4. Patients with acute and chronic renal insufficiency requiring dialysis treatment;
5. Severe craniocerebral injury, brain tumor, increased intracranial pressure, cerebrovascular accident, coma, epileptic status, etc. 6 Medical Ethics Committee of the First Affiliated Hospital of Ningbo University;
6. Patients with a history of alcohol or drug abuse;
7. Any condition that prevents the correct assessment of cognitive function, such as speech and sensory disorders or mental disorders (language difficulties or organic mental dysfunction);
8. Failure to obtain informed consent or authorization;
9. Participate in other exploratory clinical trials within 6 months prior to screening;
10. Known or suspected allergy to the study drug.