Effect of remimazolam versus propofol for the induction of general anesthesia on cerebral blood flow and oxygen saturation in elderly patients undergoing carotid endarterectomy

BACKGROUND: This study was conducted to investigate the effects and safety of remimazolam versus propofol on cerebral oxygen saturation and cerebral hemodynamics during the induction of general anesthesia in patients receiving carotid endarterectomy (CEA), so as to provide theoretical basis for better clinical application of remimazolam. METHODS: Forty-three patients (60–75 years old) with carotid artery stenosis (carotid artery stenosis greater than 70%) were randomly divided into the remimazolam group (R group) and the propofol group (P group). Anesthesia was induced with remimazolam (0.3 mg/kg) or propofol (1.5-2 mg/kg) individually. At time of admission (T0), post-anesthesia induction (T1), consciousness disappears (T2), 1 min after loss of consciousness (T3), 2 min after loss of consciousness (T4) and pre-endotracheal intubation (T5), measurement in patients with regional cerebral oxygen saturation (SrO(2)), average blood flow velocity (Vm), resistance index (RI), mean arterial pressure (MAP), heart rate (HR) and cardiac index (CI) were recorded. RESULTS: SrO(2) increased significantly in both groups after induction of anesthesia compared with baseline (P < 0.05) and decreased after loss of consciousness (P < 0.05). There was no difference in the mean value of the relative changes in SrO(2) between the groups. Meanwhile, the Vm, RI, HR and CI of each time point between two groups showed no statistically significant difference (P > 0.05) while MAP in group P at T5 was lower than that in group R individually(P < 0.05). In each group, Vm, HR, CI and MAP at T2-T5 were all significantly reduced compared with T1, with statistically differences(P < 0.05). Specifically, there was no difference of RI at each time between or within groups(P > 0.05). CONCLUSIONS: Our study revealed that remimazolam can be administered safely and effectively during the induction of general anesthesia for carotid endarterectomy in elder population and it demonstrated superiority in hemodynamic changes compared with propofol. CLINICAL TRIAL REGISTRATION: This trial was retrospectively registered with the Chinese Clinical Trial Registry. Registration number: ChiCTR2300070370. Date of registration: April 11, 2023.