Safety and efficacy of remimazolam compared with propofol for general anesthesia during cold knife conization: a...

Cold knife conization is usually performed under general anesthesia without intubation. This type of anesthesia is more critical in terms of the properties of the sedative drugs. Remimazolam is a novel ultrashort-acting benzodiazepine in which the lipid bond can be rapidly hydrolyzed by nonspecific lipases in the plasma. Therefore, remimazolam can be used for general anesthesia without intubation in patients undergoing short procedures. In this study, we compared the safety and efficacy of remimazolam with those of propofol for cold knife conization.

This single-center, randomized controlled trial screened 104 patients, and 90 were randomly assigned to receive propofol (P, N = 45) or remimazolam (R, N = 45) during cold knife conization. All the patients received a 1 µg/kg fentanyl injection. The patients received 1.5 mg/kg propofol or 0.2 mg/kg remimazolam injection, followed by a rate of 4 ~ 12 mg/kg/h or 1.0 ~ 3.0 mg/kg/h continuous intravenous infusion, respectively, to keep the patient state index (PSi) between 35 and 50. The primary outcome was intraoperative hypoxemia. The secondary outcomes were hemodynamic parameters, respiratory parameters, and other adverse events.

The incidence of intraoperative hypoxemia in the R group was significantly lower than that in the P group (46.7% vs. 71.1%, p = 0.018). Compared with patients in the P group, patients in the R group had fewer changes in the respiratory rate, mean arterial pressure and heart rate at some time points during surgery. The incidences of hypotension (15.6% vs. 35.6%, p = 0.030) and injection pain (42.2% vs. 84.4%, p < 0.001) were lower in the R group than in the P group; however, patients in the R group required more time to awaken (7.9 ± 4.5 min vs. 4.3 ± 1.7 min, p < 0.001).

In conclusion, patients in the R group had a lower incidence of hypoxemia and fewer hemodynamic changes than did patients in the P group. Thus, remimazolam can be safely used for unintubated general anesthesia in patients undergoing cold knife conization.

The trial registration number is ChiCTR2200065519.