Comparison of Hemodynamics and Respiratory Function Between Ciprofol and Propofol in Elderly Patients Undergoing Non-intubated General Anesthesia

Inclusion Criteria

1. Patients scheduled for elective non-intubated general anesthesia 2. Age ranging from 65 to 80 years old 3. American Society of Anesthesiologists (ASA) physical status class I-III 4. Written informed consent signed by the patient or legal guardian

Exclusion Criteria

1. Confirmed allergy to propofol, ciprofol or their excipients 2. Severe cardiovascular diseases (uncontrolled hypertension, heart failure, severe arrhythmia, etc.) 3. Severe respiratory diseases (chronic obstructive pulmonary disease, obstructive sleep apnea syndrome, etc.) 4. Severe hepatic or renal insufficiency 5. Long-term regular use of sedatives or opioids 6. Baseline bradycardia (HR \< 50 beats/min) or hypoxemia (SpO₂ \< 90%) Elimination Criteria

1\. Patients with allergic reactions to study drugs or other severe complications during the trial

2\. Severe hypoxemia requiring emergency endotracheal intubation

3\. Severe hemodynamic instability occurring during induction

4\. Incomplete monitoring data caused by equipment malfunction Randomization and Group Allocation A total of 108 eligible elderly patients undergoing elective non-intubated general anesthesia at the Cardiovascular and Cerebrovascular Disease Hospital, General Hospital of Ningxia Medical University will be recruited. A computer-generated random number sequence will allocate subjects at a 1:1 ratio into the ciprofol group (Group C) and the propofol group (Group P).

Observation Indicators

Baseline Demographic Data

Gender, age, height, weight, BMI, ASA classification, smoking history, alcohol consumption, underlying diseases, Modified Mallampati score, thyromental distance, snoring history, etc.

Primary Observation Indicators

Hemodynamic parameters (HR, SBP, DBP, MAP, CO, SV, SVR) and respiratory parameters (SpO₂, respiratory rate (RR), PETCO₂) will be recorded at baseline, loss of consciousness, 30 s, 1 min, 2 min, 3 min, 4 min and 5 min after loss of consciousness.

Secondary Observation Indicators

1. Baseline BIS value and minimum BIS value during induction 2. Total induction dosage, induction time (from drug administration to MOAA/S ≤ 1), recovery time (from last drug administration to MOAA/S = 5) 3. Incidence of adverse reactions: injection pain, involuntary movement, hiccup, hypotension, bradycardia, hypoventilation, apnea, hypoxemia, etc.

Anesthetic Protocol

All patients fast for 8 hours and abstain from clear liquids for 4 hours preoperatively. After entering the operating room, oxygen inhalation is initiated, upper limb venous access is established, and monitors including pulse oximetry, sidestream PETCO₂ monitor, continuous non-invasive arterial blood pressure monitor and bispectral index (BIS) monitor are connected.

Midazolam 0.01 mg/kg is administered intravenously first; stable circulatory and respiratory readings thereafter serve as baseline values. Ciprofol or propofol is then infused intravenously at 10 mL/min. Sedation depth is assessed every 5 seconds via MOAA/S scale; drug infusion is stopped once MOAA/S ≤ 1 (loss of consciousness). The total induction dose is recorded. All hemodynamic and respiratory indicators are documented at predefined time points.

Anesthesiologists may supplement 1/3 of the initial induction dose if the patient shows eye opening, verbal response or body movement, with an interval of at least 1 minute between supplemental doses.

Rescue Management Protocols

* Hypotension (SBP \< 90 mmHg or MAP decreased by \>20% from baseline lasting \>2 min): ephedrine 6 mg IV * Severe bradycardia (HR \< 45 beats/min lasting \>30 s): atropine 0.5 mg IV * Hypoventilation (RR \< 8 bpm, PETCO₂ less than half baseline or PETCO₂ ≥45 mmHg lasting \>30 s) * Apnea (no thoracic movement or flat PETCO₂ waveform lasting \>10 s) * Hypoxemia (SpO₂ \< 93%) / severe hypoxemia (SpO₂ \< 85%) For respiratory compromise, jaw thrust, increased oxygen flow or mask-assisted ventilation will be applied; emergency endotracheal intubation will be performed if necessary.

• Brain electrical activity sedation depth (BIS) [Time frame: 5 minutes after induction of anesthesia]
• incidence of induction period circulatory/respiratory adverse events [Time frame: 5 minutes after induction of anesthesia]