Efficacy and Safety of Remimazolam versus Dexmedetomidine and Midazolam in Awake Endotracheal Intubation for Difficult Airway Patients: A Randomized Controlled Study.

Objective: To compare the safety and efficacy of remimazolam, dexmedetomidine, and midazolam in awake endotracheal intubation by flexible bronchoscopy for patients with difficult airways. Methods: Ninety patients with difficult airways undergoing elective surgical procedures requiring awake endotracheal intubation under general anesthesia were randomly assigned to three groups, with 30 patients per group: Group M (midazolam), which received a 0.04 mg/kg intravenous (IV) bolus; Group D (dexmedetomidine), which was given via intravenous infusion pump at a rate of 1.0 µg/kg/min for 10 minutes; and Group R (remimazolam), which received a 0.15 mg/kg IV bolus. All patients first received 0.1μg/kg of sufentanil intravenously for basic analgesia. A 2-minute interval was allowed to ensure initial onset of the analgesic effect, followed by administration of the respective sedative agents for each group as detailed above. Upon achieving a Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score of≤2, pharyngeal topical anesthesia was administered, followed by flexible fiberoptic endotracheal intubation. The primary outcome measure was the first-attempt intubation success rate. All other evaluated parameters were defined as secondary outcomes. Mean arterial pressure (MAP), heart rate (HR), and oxygen saturation (SpO2) were recorded at four time points: baseline (T0), immediately before intubation (T1), immediately after intubation (T2), and 3 minutes post-intubation (T3). Additional outcomes assessed included the duration of anesthetic induction, the interval from induction to intubation, patient comfort levels, post-induction MOAA/S scores, and the incidence of adverse events. Results: The first-attempt intubation success rates across the three groups were 70%, 93.3%, and 100%, respectively. Compared with the values at T1, mean arterial pressure (MAP) and heart rate (HR) were significantly higher in Group M at T2 and T3 (both P<0.05). In Group D, HR at T1 was significantly lower than that at T0 (P<0.05). For inter-group comparisons, HR in Group D was significantly lower than in Group R at T1 (P<0.05). Additionally, Group D had the longest duration of anesthetic induction and the longest interval from induction to intubation (both P<0.05). Compared with Group M, both Group D and Group R exhibited significantly higher first-attempt intubation success rates (P<0.05). Group R achieved the highest patient comfort scores, the highest success rate of sedation after a single induction dose, and the lowest incidence of adverse events (all P<0.05). Conclusion: Remimazolam provides effective sedation for awake tracheal intubation in patients with difficult airways. It exerts minimal impact on respiratory and circulatory function, is associated with fewer adverse events, and yields a higher intubation success rate, making it a favorable option for this patient population.