Apnea during moderate to deep sedation using continuous infusion of remimazolam compared to propofol and dexmedetomidine: A retrospective observational study

Remimazolam's rapid onset and offset make it an innovative sedative for use during regional anesthesia. However, its respiratory safety profile is not well understood. We compared the continuous infusion of remimazolam with commonly used sedatives, propofol and dexmedetomidine, after regional anesthesia. In this retrospective study, the incidence of apnea (>10 seconds) was assessed in patients who underwent orthopedic surgery under regional anesthesia and received moderate to deep sedation using continuous infusion of remimazolam (group R: 0.1 mg/kg in 2 minutes followed by 0.5 mg/kg/hr). The incidence was compared with that of propofol (group P: 2-3 μg/mL target-controlled infusion) and dexmedetomidine (group D: 1 μg/kg in 10 minutes followed by 0.4-1 μg/kg/hr). Propensity score weighted multivariable logistic regression model was utilized to determine the effects of the sedative agents on the incidence of apnea. A total of 634 (191, 278, and 165 in group R, P, and D) cases were included in the final analysis. The incidence of apnea was 63.9%, 67.3%, and 48.5% in group R, P, and D, respectively. The adjusted odds ratios for apnea were 2.33 (95% CI, 1.50 to 3.61) and 2.50 (95% CI, 1.63 to 3.85) in group R and P, compared to group D. The incidence of apnea in patients receiving moderate to deep sedation using continuous infusion of remimazolam with dosage suggested in the current study was over 60%. Therefore, careful titration and respiratory monitoring is warranted.

Remimazolam to prevent hemodynamic instability during catheter ablation under general anesthesia: a randomized controlled trial

PURPOSE

Maintaining hemodynamic stability during cardiac ablation under general anesthesia is challenging. Remimazolam, a novel ultrashort-acting benzodiazepine, is characterized by maintaining comparatively stable blood pressure and does not influence the cardiac conduction system, which renders it a reasonable choice for general anesthesia for cardiac ablation. We aimed to evaluate whether remimazolam is associated with a decreased incidence of intraoperative hypotension compared with desflurane.

METHODS

In this single-centre, parallel-group, prospective, single-blind, randomized clinical trial, we randomized patients (1:1) into a remimazolam group (remimazolam-based total intravenous anesthesia) or desflurane group (propofol-induced and desflurane-maintained inhalational anesthesia) during cardiac ablation procedures for arrhythmia. The primary outcome was the incidence of intraoperative hypotensive events, defined as mean arterial pressure of < 60 mm Hg at any period.

RESULTS

Overall, we enrolled 96 patients between 2 August 2022 and 19 May 2023 (47 and 49 patients in the remimazolam and desflurane groups, respectively). The remimazolam group showed a significantly lower incidence of hypotensive events (14/47, 30%) than the desflurane group (29/49, 59%; relative risk [RR], 0.5; 95% confidence interval [CI], 0.31 to 0.83; P = 0.004). Remimazolam was associated with a lower requirement for bolus or continuous vasopressor infusion than desflurane was (23/47, 49% vs 43/49, 88%; RR, 0.56; 95% CI, 0.41 to 0.76; P < 0.001). No between-group differences existed in the incidence of perioperative complications such as nausea, vomiting, oxygen desaturation, delayed emergence, or pain.

CONCLUSIONS

Remimazolam was a viable option for general anesthesia for cardiac ablation. Remimazolam-based total intravenous anesthesia was associated with significantly fewer hypotensive events and vasopressor requirements than desflurane-based inhalational anesthesia was, without significantly more complications.

STUDY REGISTRATION

ClinicalTrials.gov (NCT05486377); first submitted 1 August 2022.