Remimazolam Reduces the Cough Reflexes in Elderly Patients Undergoing Fiberoptic Bronchoscopy Under Remifentanil/Cipepofol-Based Anaesthesia: A Randomized Clinical Trial

Background: Fiberoptic bronchoscopy (FOB) is one of the most common critical procedures for diagnosis and treatment of respiratory diseases. We aimed to determine whether remimazolam reduces the cough reflexes in patients undergoing FOB under remifentanil/cipepofol-based anaesthesia. Methods: This was a single-center, single-blinded, randomized study. We included 90 adult patients underwent FOB with ASA I–III, aged 60– 90 years. Patients were randomly assigned to cipepofol (CIP) group or remimazolam-cipepofol (RMZ-CIP) group. In the CIP group, anaesthesia was induced sequentially with remifentanil and cipepofol. In the RMZ-CIP group, anaesthesia was induced sequentially with remifentanil, remimazolam, and cipepofol. A laryngeal mask airway (LMA) was inserted in both groups when the BIS ≤ 60. Anaesthesia was maintained with remifentanil and cipepofol with a BIS value between 40 and 60. The primary outcome was the incidence and severity of cough reflexes during the first FOB. The secondary outcomes included vital signs, characteristics of FOB and anaesthesia, administration of vasoactive drugs, and adverse events. Results: The incidence of cough reflexes during FOB was lower in the RMZ-CIP group than that in the CIP group (38% vs 62%, p =0.029). The total consumption of cipepofol and remifentanil was higher in CIP group than in the RMZ-CIP group (40.89 [31.41– 61.90] mg vs 27.019 [21.41– 41.91] mg, p < 0.001; 0.38 [0.42– 0.50] mg vs 0.22 [0.20– 0.26] mg, p < 0.001). Cipepofol consumption during anaesthesia induction was higher in the CIP group than in the RMZ-CIP group ( p < 0.001). No difference was found in terms of vital signs, the characteristics of FOB, anaesthesia, and adverse events. Conclusion: The combination of remimazolam reduced the incidence of cough reflexes and dosage of cipepofol and remifentanil in elderly patients undergoing FOB under remifentanil/cipepofol-based anaesthesia. Clinical Trial Registration: Chinese Clinical Trial Registry (ChiCTR2300079139). Keywords: remimazolam, cipepofol, cough reflex, fiberoptic bronchoscopy