The evidence on the practice of remimazolam besylate during cardiac anesthesia is scarce. This study investigates the efficacy and safety of remimazolam besylate general induction and maintenance during cardiac surgery.

Remimazolam besylate (RB), as a new benzodiazepine sedative agent, has been approved in clinical anesthesia with prominent characteristics of short onset/offset, less depression for cardiovascular or respiratory function and specific antagonist. Some studies have confirmed the comparable anesthesia efficacy of remimazolam for outpatient digestive endoscopy, fiberoptic bronchoscopy, facial plastic and orthopedic surgery as propofol. Currently, the evidence on its application in cardiac anesthesia is insufficient. Our study aims to evaluate the efficacy of remimazolam besylate and propofol and provide an ideal anesthetic agent to achieve the goal of early recovery after cardiac surgery.

Inclusion Criteria:

1. Elective cardiac surgery via cardiopulmonary bypass;
2. Aged 18-65 years;
3. American Society of Anesthesiologists (ASA) grade I-III;
4. Body mass index (BMI) 18-28 kg/m2.

Exclusion Criteria:

1. A history of sternotomy for heart disease;
2. Angina or arrhythmia with severe dynamics flutters pre-operation;
3. Respiratory, hepatic or renal dysfunction (oxygenation index<300, alanine transaminase> 2 upper limits of normal value, creatinine > 200 μmol/L);
4. Diagnosed with advanced tumors;
5. Psychiatric or mental disorders;
6. Myasthenia gravis or seizures;
7. Pregnant or lactating females;
8. A history of benzodiazepines administration within 3 months before surgery;
9. Known allergic to benzodiazepines, opioids, propofol and flumazenil;
10. Involved in another interventional clinical trial.