Patterns of remimazolam use and recovery after procedural sedation and anaesthesia: a multicentre cohort study

Remimazolam is increasingly used for procedural sedation and anaesthesia, yet real-world data across diverse clinical environments remain limited.

We conducted a retrospective cohort study of all patients receiving remimazolam in a multisite US academic health system between 1 June 2021 and 29 February 2024. The primary outcome was patterns of remimazolam use, including recovery characteristics (time to return to baseline Richmond Agitation-Sedation Scale [RASS] score and PACU discharge readiness times). Secondary outcomes included flumazenil use and the incidence of critical events such as allergic reactions, cardiorespiratory depression, or death. Associations were analysed using linear mixed models and reported as geometric mean ratios (GMR) with 95% confidence intervals (CIs).

The cohort included 8011 patients undergoing 9431 procedures (median age 67 yr, inter-quartile range [IQR] 56-76), 85.2% of whom were ASA Physical Status ≥3. Most procedures (70.5%) occurred outside the operating room. Median remimazolam dose was 12 mg (IQR 8-20). Median time to baseline RASS was 13 min (IQR 5-30), and median PACU discharge readiness time was 30 min (IQR 15-55). In cardioversion cases, flumazenil use was associated with shorter PACU discharge readiness time (adjusted GMR 0.83, 95% CI 0.75-0.93; P<0.001) and shorter time to baseline RASS (adjusted GMR 0.63, 95% CI 0.48-0.83; P<0.001). Higher remimazolam dose was associated with longer recovery times (P<0.001), with a plateau observed above approximately 18 mg. Critical events occurred in 0.7% of procedures, including four possible IgE-mediated reactions (0.04%).

In this large multicentre cohort, remimazolam was associated with rapid recovery and low rates of serious adverse events across diverse procedural settings and patient acuity levels.