2.1 General information
Sixty-two patients who underwent painless abortion in our hospital from February to April 2022, aged 18–45 years, weighing 40–80 kg, and at gestational weeks 6– 10 were selected. This study was approved by the ethics committee of our hospital (approval number: IRB-2020-013). All patients or their families provided written informed consent.
2.2 Inclusion criteria
All patients met the following conditions for inclusion: age of 18–45 years; body weight of 40–80 kg; gestational weeks 6– 10; normal preoperative consciousness; imaging examination showing early intrauterine pregnancy; no recent use of sedative analgesic drugs; no history of mental nervous system diseases; no obvious abnormalities revealed by laboratory tests and imaging; and American Society of Anesthesiologists (ASA) grade I–II.
2.3 Exclusion criteria
Patients meeting any of the following criteria were excluded: severe preoperative respiratory and circulatory diseases; long-term use of sedatives, analgesics, or antidepressant drugs; myasthenia gravis; allergy to benzodiazepines, propofol, or opioids; severe liver and kidney dysfunction; unhealed, recent acute upper respiratory tract infection, asthma attacks, and persistent respiratory issues; possibility of experiencing serious surgical complications due to potential or coexisting diseases (such as family history of malignant hyperthermia or allergic constitution); difficult airways (modified Mallampati grade III–IV, mouth opening of less than 3 cm or the width of the examiner's two transverse fingers, thyromental distance 6 cm less than the examiner's three transverse fingers, lower temporomandibular joint mobility, and limited range of head and neck movement); operation time exceeding 20 min; and lack of informed consent.
2.4 Drugs and instruments
Remazolam toluenesulfonate for injection (specification: 36 mg each; batch number: 210418AK; approval number: H20190034; Jiangsu Hengrui Pharmaceutical Co., Ltd.). Fentanyl citrate injection (specification: 2 mL each; 0. 1 mg; batch number: 01D07051; approval number: H42022076; Yichang Renfu Pharmaceutical Co., Ltd.).
Propofol emulsion injection (specification: 20 mL; 200 mg; batch number: 5A210712;
approval number: H20051842; Guangdong Jiabo Pharmaceutical Co., Ltd.). Portable multi-parameter monitor (CM-33130259 Shenzhen Mindray Products). Disposable 5 mL, 10 mL, and 20 mL syringes (Guangzhou Huashan Medical Plastics Factory). ECG electrodes (Jiadenuo Health Co., Ltd.). Sodium chloride injection (500 mL; 4.5 g; batch number: 220712501; Guangdong Daxiang Pharmaceutical Co., Ltd.).
Dopamine injection (specification: 20 mg each; batch number: 2112011; approval
number: H32023366; Yabang Pharmaceutical Co., Ltd.). Atropine sulfate injection
(specification: 0.5 mg per rat; batch number: 22033105; approval number:
H34021900; Anhui Changjiang Pharmaceutical Co., Ltd.). Flumazenil injection (specification: 0.5 mg; batch number: EC2102; approval number: H20063822; Zhejiang Xianbu Pharmaceutical Co., Ltd.).
2.5 Research methodology
2.5.1 Experimental grouping
Sixty-two patients who underwent painless abortion in our hospital from February to April 2022 were selected and randomly divided into the following two groups: remazolam tosylate for injection + fentanyl (RF group) or propofol + fentanyl group (PF group) (n=31/group). The operations were performed by the same surgeon, and neither the surgeon nor the patient was aware of the grouping.
2.5.2 Operation steps
All patients received no preoperative anesthetic drugs, fasted for 8 h, and fasted for 6 h. After entering the operating room, the upper extremity superficial vein was accessed, the lithotomy position was determined, and the nasal catheter was set at low flow (2 L/min). Baseline measures of finger oxygen saturation, blood pressure, HR, the Narcotrend Index, MOAA/S score and other variables were conducted. After towel disinfection, all patients were slowly injected with fentanyl citrate ( 1 μg/kg). Based on previous studies, the RF group received intravenous injection of remazolam tosylate (0.26 mg/kg; 1.3 ED50), and the PF group received an intravenous injection of propofol emulsion (2 mg/kg). The operation began after disappearance of the eyelash reflex. Propofol ( 1 mg/kg) was added for rescue sedation according to body movement and the operation duration. Post-operation, patients were sent to the daytime anesthesia recovery room for resuscitation, and vital sign data, recovery time, and complications encountered in the recovery room were recorded by the author. Once a patient reached the Post Anesthesia Care Unit (PACU) standard of recovery, he or she was discharged, accompanied by family members.
2.5.3 Treatment of adverse reactions
In the event of hypotension (MAP ≤ 65 mmHg or systolic blood pressure ≤ 80 mmHg or a decrease by more than 20% of baseline blood pressure), a 2 mg intravenous dopamine injection was administered. An injection of 0.5 mg atropine was administered if HR slowed to ≤ 45 beats/min. In the event of respiratory depression (fingertip pulse SpO2 < 90 %), the chin-raising method was used or breathing balloon mask pressurized oxygen-assisted breathing was initiated.
2.5.4 Observation indicators
Recorded factors included the patient 's age, weight, gestational age, HR, MAP, SpO2, Narcotrend Index, MOAA/S score, awakening time (T7), the number of incidences and durations of remedial sedation, and the incidence of dizziness and headache, nausea and vomiting, injection pain, respiratory depression, circulatory inhibition, abortion syndrome, dreaming, euphoria, intraoperative awareness, and other adverse reactions. The values were compared between the two groups at eight time points:
after operating room entry (T0), 1 min post-fentanyl administration (T1), 1 min post-remifentanil/propofol administration (T2), at the beginning of the operation (T3), 3 and 5 min post-operation (T4 and T5), at the end of the operation (T6), and upon awakening (T7).
2.6 Assessment of alertness/sedation
Alertness/sedation was classified based on MOAA/S Scale scores, as summarized in Table 1.
2.6 Modified Brice Questionnaire
Patients’ anesthetic experiences were assessed via the Modified Brice Questionnaire, which comprised the following five questions: 1) What is the last thing you remember before you fell asleep?; 2) What is the first thing you remember when you woke up?; 3) What do you remember between the two?; 4) Did you dream during the operation?; and 5) What do you feel was the worst thing about this operation?
2.7 Discharge criteria
A PACU standard modified Aldrete score of ≥ 9 points was required for discharge. These criteria are summarized in Table 2.
2.8 Statistical analysis and processing
Statistical Package for the Social Sciences (SPSS) 26.0 software was used for data processing. Measurement data with a normal or approximately normal distribution are expressed as the mean ± standard deviation. Independent samples t-tests were used for inter-group comparisons, and repeated measures analysis of variance was used for intra-group comparisons at different time points. Count data are expressed as percentages (%) and compared using the chi-square test. P<0.05 was considered statistically significant.