Effects of remimazolam on hemodynamic changes during cardiac ablation for atrial fibrillation under general anesthesia: a propensity-score-matched retrospective cohort study

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.

Effectiveness of remimazolam in preventing postoperative delirium in elderly patients with proximal femoral fractures

PURPOSE

Elderly patients with proximal femoral fractures are known to be a high-risk group for postoperative delirium (POD). The aim of this study was to determine the association of the benzodiazepine drug remimazolam with POD in elderly patients with proximal femoral fractures.

METHODS

In this single-center retrospective observational study, we included patients aged 65 years or older who underwent general anesthesia for proximal femoral fractures. We collected data for the incidence of POD within 3 days after surgery. We also obtained data for complications, preoperative blood examinations, maintenance anesthetic and intraoperative vital data. The occurrence of POD in patients who received remimazolam for general anesthesia (remimazolam group) was compared to that in patients who received general anesthesia with other anesthetic agents (other group). We finally conducted a multivariate analysis to assess the independent association of remimazolam with the risk of POD.

RESULTS

A total of 230 patients, including 54 patients who received remimazolam for maintenance anesthesia, were included in this study. The incidence of POD in the patients was 26.1%. The incidence of delirium within 3 days after surgery was significantly lower in the remimazolam group than in the other group (14.8% vs. 29.5%, p  =  0.03). The multivariate analysis showed that the use of remimazolam independently reduced the occurrence of POD (adjusted odds ratio  =  0.42, p  =  0.04).

CONCLUSION

This retrospective observational study showed that the use of remimazolam is independently associated with a reduced incidence of POD. Remimazolam may be considered as an option to reduce POD in elderly patients with proximal femoral fractures.

Anesthesia Management Using Remimazolam for Lower Limb Amputation in a Patient With Septic Shock Due to Necrotizing Fasciitis

We report a case of a patient with necrotizing fasciitis and septic shock caused by streptococcal toxic shock syndrome, who was anesthetized and managed with remimazolam. The patient, a woman in her 40s, was admitted to the ICU with a diagnosis of necrotizing fasciitis of the right lower extremity and septic shock and was scheduled for above-the-knee amputation under general anesthesia. She was anesthetized with remimazolam for sedation and fentanyl and remifentanil for analgesia. Intraoperatively, we were able to maintain hemodynamic stability with similar or only slightly higher doses of circulatory agonists during admission. In the present case, remimazolam, an ultrashort-acting benzodiazepine, was safely used to provide anesthesia to a patient in septic shock due to necrotizing fasciitis, who was receiving high doses of vasopressor agents for cardiovascular support, as it was necessary to select an anesthetic drug that would cause minimal circulatory depression.

Effect of acute normovolemic hemodilution in patients undergoing cardiac surgery with remimazolam anesthesia

PURPOSE

The reduced effects of allogeneic transfusion with acute normovolemic hemodilution (ANH) have been reported. Harvesting a large volume of blood may maximize the effect in patients with low body weight, and the prevention of hypotension is important. Remimazolam is an anesthetic with few circulatory responses. Our aim was to evaluate whether high-volume ANH reduces the need for transfusion in cardiac patients under remimazolam anesthesia.

METHODS

In this retrospective single-center study, we enrolled cardiopulmonary bypass (CPB) patients who received remimazolam anesthesia. Changes in hemodynamic parameters were assessed. The numbers of blood transfusions and chest tube outputs were also evaluated.

RESULTS

In a total of 51 patients, ANH was performed in 27 patients with a mean body mass index of 23.2 (ANH volume: 740 ± 222 mL). No significant differences were observed in mean blood pressure during blood collection. The intraoperative amount of red blood cell (RBC) transfusion was significantly lower in the ANH group than in the control group (431 ± 678 and 1260 ± 572 mL, p < 0.001). The avoidance rates of RBC were 66.7 and 4.2%, respectively. The multivariate analysis result revealed that ANH correlated with RBC, with an odds ratio of 0.067 (95% confidence interval 0.005-0.84, p < 0.05). The postoperative bleeding at 24 h was significantly lower in the ANH group (455 ± 228 and 797 ± 535 mL, p < 0.01).

CONCLUSION

In patients undergoing CPB, ANH reduced intraoperative transfusion amount and postoperative bleeding. Hemodynamic changes during blood collection were minimal under remimazolam anesthesia and high-volume ANH was feasible.

Effect of Remimazolam on Pain Perception and Opioid-Induced Hyperalgesia in Patients Undergoing Laparoscopic Urologic Surgery-A Prospective, Randomized, Controlled Study

Background and Objectives: The effects of midazolam, a benzodiazepine, on pain perception are complex on both spinal and supraspinal levels. It is not yet known whether remimazolam clinically attenuates or worsens pain. The present study investigated the effect of intraoperative remimazolam on opioid-induced hyperalgesia (OIH) in patients undergoing general anesthesia. Materials and Methods: The patients were randomized into three groups: group RHR (6 mg/kg/h initial dose followed by 1 mg/kg/h remimazolam and 0.3 μg /kg/min remifentanil), group DHR (desflurane and 0.3 μg /kg/min remifentanil) or group DLR (desflurane and 0.05 µg/kg /min remifentanil). The primary outcome was a mechanical hyperalgesia threshold, while secondary outcomes included an area of hyperalgesia and clinically relevant pain outcomes. Results: Group RHR had a higher mechanical hyperalgesia threshold, a smaller hyperalgesia postoperative area at 24 h, a longer time to first rescue analgesia (p = 0.04), lower cumulative PCA volume containing morphine postoperatively consumed for 24 h (p < 0.01), and lower pain intensity for 12 h than group DHR (p < 0.001). However, there was no significant difference in OIH between groups RHR and DLR. Conclusions: Group RHR, which received remimazolam, attenuated OIH, including mechanically evoked pain and some clinically relevant pain outcomes caused by a high dose of remifentanil. Further research is essential to determine how clinically meaningful and important the small differences observed between the two groups are.