Discussion
anxiety, respiratory adverse, pain, hypoxemia, respiratory depression, nerve block
ADVERSE EFFECTS, RESPIRATORY DEPRESSION
Present study showed that supplementation of remimazolam to sufentanil improved the success rate of procedure sedation both in young and elderly patients during nerve block. These patients also experienced lower pain intensity and higher self-reported satisfaction. To be noted, remimazolam 0.08 mg/kg provided the best sedation efficacy in young patients while remimazolam 0.04 mg/kg with the trend of less respiratory adverse events was more optimal for elderly patients.MOAA/S was commonly used for perioperative assessment of sedation level, especially for procedure sedation [Remimazolam was usually given as a single fixed dose in most studies. A recent study simulating population pharmacodynamic with Markov mixed-effects model showed that 5 mg remimazolam with fentanyl provided superior sedation in comparison with dose of 4 or 6 mg [Our study showed that the success rate of procedure sedation was significantly increased in patients treated with remimazolam. To our knowledge, this was the first study to investigate the sedation efficacy of remimazolam during nerve block. In young patients, the success rate was positively associated with the increment of remimazolam dosage, i.e., from 43.3% in control group to 80.0% in high dose of remimazolam. In elderly patients, we also noticed that higher dose of remimazolam was associated with an increased trend of adverse effects such as respiratory depression and hypoxemia. Elderly patients also experienced longer duration of recovery time which was up to 15 min with remimazolam dosed at 0.06 mg/kg, which was consistent with previous study [Success rate of nerve block can be affected by many predisposing factors such as anxiety and sleep. Preoperative anxiety status and sleep quality was comparable among each group in the present study. Patients who received remimazolam had lower pain intensity during nerve block and higher score of self-reported satisfaction. It seemed that remimazolam may enhance the analgesic effect of opioids via synergistic effects [Our study had some limitations. First, pharmacodynamic parameters of remimazolam with sufentanil were not examined. Second, dose of sufentanil was fixed in our present study, and further studies should be taken to search optimal combination regimen of remimazolam and sufentanil. Third, generalization of our result to other clinical scenario with severe pain procedure should be cautioned because these procedures may need more analgesics with opioids.