Background and objectives Elderly individuals have a greater sensitivity to sedation, and the most commonly used drugs for sedation are benzodiazepines, which exhibit some complication. Therefore, this study aimed to compare the use of dexmedetomidine and midazolam regarding proper sedation and postoperative complications in elderly individuals who require intraoperative sedation.

Methods This study was a parallel-randomized clinical trial, which included 120 patients aged >70 years undergoing regional anesthesia and sedation. The exclusion criteria consisted of bradycardia, heart failure, respiratory failure, a Glasgow Coma Scale ≤14, liver failure and refusal to participate. Patients were divided into two groups: the first group received midazolam (MDZ), while the second group received dexmedetomidine (DEX). The doses were titrated to achieve an intraoperative Richmond Agitation-Sedation Scale (RASS) score between −3 and −1. Incidences of complications were recorded.

Results During a 120 min follow-up, the depth of sedation (RASS score) revealed variations less often in the DEX group (p=0.002). Patients in the DEX group (n=67) had lower rates of intraoperative complications (19.4% vs 73.6%, p<0.001). Intraoperatively, the incidence rates of psychomotor agitation (15.1% vs 1.5%, p=0.005), arterial hypotension (28.3% vs 3.0%, p<0.001) and respiratory depression (73.6% vs 0%, p<0.001) were higher in the MDZ group (n=53). During postanesthesia care, the incidence rates of shivering (p<0.001), residual sedation (p=0.04) and use of supplemental oxygen (p<0.001) were significantly lower in the DEX group.

Conclusions The use of DEX for sedation during surgery provides better control over the depth of sedation and produces fewer complications in elderly individuals.

Trial registration number NCT02878837.