Materials and Methods
Patients and Study Protocol
The study was approved by the Ethics Committee of Weifang People's Hospital and registered with the China Clinical Trials Registry (ChiCTR2100053316). The subjects was 192 patients of ASA1–2 level, aged between 18 and 65 years, who were about to undergo gynaecological day surgery at the First Clinical Medical College of Weifang Medical College. Exclusion criteria were breastfeeding, a history of chronic pain, a history of sedative and analgesic administration or allergy to any of the study drugs, severe hypertension, and diabetes mellitus. Reject criteria were a procedure time of more than 1 h, discharged the next day, missing follow-up with the electronic questionnaire pushed 24 h after the procedure. Randomly divided into 3 groups: DD group (dexamethasone combined with droperidol group), DT group (dexamethasone combined with Tropisetron group) and DC group (dexamethasone group). The computer-generated random allocation sequence was created by an independent investigator using Excel 2016 (Microsoft) with a 1:1:1 allocation and random block sizes. On the morning of the surgery, the anesthesia nurse opened the envelope containing the anesthesia scheme of the enrolled patients and then prepared the drugs. Each drug was diluted to 10 ml with normal saline, and the drug type was identified without the drug name. Participants and outcome assessors were blinded to group allocation.
Patients were assessed by the anesthesia clinic before admission and confirmed to be ready for day surgery. On the day of surgery, patients were admitted to the room and re-confirmed to be free of contra-indications and then intravenous access was established, lactated ringer's solution was infused and NIBP, HR and SPO2 were monitored. flurbiprofen axetil 50 mg and dexamethasone 5 mg were given intravenously before induction of anesthesia and 2 min later droperidol 1 mg was given to the DD group, tropisetron 5 mg to the DT group and saline (5 ml) to the DC group. Induction of anesthesia: remimazolam 6 mg/kg/h was continuously infused until sleep, mivacurium 0.2 mg/kg and alfentanil 20ug/kg were slowly injected, 3 min later tracheal intubation was performed to control breathing. Anesthesia maintenance: alfentanil 40ug/kg/h and remimazolam 1 mg/kg/h continuous infusion, stop infusion at the end of the operation. A single dose of remimazolam 2 mg or and alfentanil 80ug was given at the onset of intraoperative signs of decompensated anesthesia. After awakening and extubation, the patient was taken to the PACU and assessed for nausea and vomiting. Patients were discharged after meeting discharge criteria as assessed by the Post-anesthetic Discharge Scoring System (PADSS) criteria. An electronic follow-up questionnaire was pushed 24 h after the operation. Basic information about the patient's medical history and surgery was obtained through preoperative anesthesia clinic assessment, intraoperative anesthesia monitoring, in the inpatient electronic medical record, and observation notes in the PACU.
Main outcome
The incidence of PONV in the PACU.
Secondary Outcome
The incidence of PONV within 24 h after surgery; Baseline data on age, height, weight, BMI, ASA grading, Apfel score, type of surgery and general data such as remimazolam and alfentanil consumption and duration of surgery.
Sample Size and Statistical Analysis
There are no reports of PONV after general anesthesia with remimazolam combined with alfentanil. According to the literature,[4,5] we applied intravenous general anesthesia with remimazolam combined with alfentanil in gynaecological day surgery, and the anesthetic effect was good; in this study, α = 0.05 and β = 0.1 were taken and the results of the pre-test study were that the incidence PONV in the PACU was approximately 55% in the DC group, 25% in the DD group and 15% in the DT group. The sample size with statistically significant differences between the DC and DD groups was calculated to be 57 cases, with a 10% missing sample rate, so 64 cases were included in each group, for a total of 192 cases in the three groups..
SPSS 18.0 software was used for statistical analysis, and measurement data that obeyed normal distribution were expressed as mean ± standard deviation (x ± s)and compared using analysis of variance (ANOVA). Non-parametric rank sum test was used for non-normally distributed measurement data. Count data were expressed as rates or composition ratios, and the χ2 test was used. A P value of < 0.05 was considered to be statistically significant.
BMC Anesthesiol. 2022;22(292) © 2022 BioMed Central, Ltd.
