Safety of remimazolam in deep sedation during flexible fiberoptic bronchoscopy: a prospective, randomized controlled trial

Abstract

Background: Remimazolam is a novel ultrashort-acting sedative and anesthetic drug. Numerous recent studies have demonstrated its sedative effect, however, research has yet to be conducted to explore the safety of remimazolam in deep sedation flexible fiberoptic bronchoscopy (FFB) in elderly patients.

Methods: Sixty-six elderly patients who underwent FFB were randomly assigned to either the remimazolam (Group R) or propofol (Group P) group. Initially, both groups received an intravenous injection of 10 µg/kg alfentanil. Subsequently, both groups were administered experimental drugs intravenously: (1) Group R received 0.2 mg/kg remimazolam, and (2) Group P received 1.5 mg/kg propofol. Throughout the FFB, patients were maintained in a state of deep sedation (modified observer's assessment of alertness/sedation score ≤ 1) by titrating the experimental drugs as needed. The primary outcome measured was the incidence of hypoxemia during the FFB. Secondary outcomes included other safety outcomes, effectiveness outcomes, and procedural characteristics.

Results: Group R had a lower incidence of hypoxemia compared to Group P (9.1% vs. 45.5%) (RR, 0.20 [95% CI, 0.06-0.63], P = 0.001). The Minimum SpO₂ and minimum MAP in Group R was higher than in Group P (93.1 ± 3.8 vs. 89.0 ± 6.7, P = 0.004) (82.8 ± 12.4 vs. 72.8 ± 14.1, P = 0.003); ΔMAP and ΔHR in Group R was lower than in Group P (15.9 ± 5.2 vs. 28.8 ± 12.4, P < 0.001), (14.9 ± 3.2 vs. 17.8 ± 4.2, P = 0.003); the incidence of hypotension in Group R was lower than in Group P (9.1% vs. 30.3%, P = 0.030); the incidence of injection pain in Group R was lower than in Group P (0% vs. 27.3%, P = 0.001).

Conclusions: During the maintenance of elderly patients under deep sedation with FFB, remimazolam exhibited superior safety than propofol, particularly in terms of respiratory depression and cardiovascular inhibition.

Trial registration: The trial was registered, before patient enrollment, in the Chinese Clinical Trial Registry ( www.chictr.org.cn ) (clinical trial number: ChiCTR2400083383; Principal Investigator: Gongchen Duan; date of registration: 23 April 2024).

Keywords: Deep sedation; Elderly patients; Flexible fiberoptic bronchoscopy; Remimazolam.