This study intends to measure the ED95 of remimazolam-assisted sedation in arteriovenous fistula creation by BCD.

Operative venous fistula (AVF) under local anaesthesia is a common surgical procedure for long-term haemodialysis patients. A common surgical procedure for patients with renal failure on dialysis. However, due to the long duration of the procedure, patients are prone to anxiety and nervousness that Especially if it is difficult to keep quiet during the operation, it may lead to blood pressure fluctuation and other complications, affecting the operation's smooth progress of the procedure. Moderate sedation is particularly important in this type of surgery, as it can effectively relieve the patient's tension and stabilise vital signs, It can effectively relieve the patient's tension, stabilise vital signs and reduce the patient's discomfort, thus contributing to the successful completion of the operation.This study intends to measure the ED95 of remazolam-assisted sedation in arteriovenous fistula creation by BCD. This will provide a scientific basis for anaesthetic drug selection in uremic patients.

Inclusion Criteria:

• 18-65 years old (including borderline values).
• Elective surgical patients under local anaesthesia for operation of AVF
• Voluntary participation in this study and signing of informed consent.
• American Society of Anesthesiologists (ASA) classification < Grade IV.
• BMI range: 18-28kg/m2 (including borderline values).

Exclusion Criteria:

• hypersensitivity to remimazolam or benzodiazepines.
• patients with severe cardiac, pulmonary, neurological diseases or liver failure. -- Preoperative use of sedative drugs, anticonvulsants, etc.
• patients who cannot cooperate with postoperative recovery or follow-up.
• vulnerable groups, including those with mental illness, cognitive impairment, critically ill patients, pregnant women, illiterates, etc.