In children aged 3 to 6 undergoing endotracheal intubation without muscle relaxants, the combination of remimazolam and esketamine with a fixed dose of remifentanil (2.5 μg/kg) provided safe and effective intubation conditions while maintaining hemodynamic stability. Using Dixon's up-and-down method, the 50% effective dose (ED50) for esketamine was 0.74 mg/kg and the 95% effective dose (ED95) was 0.97 mg/kg. For remimazolam, the ED50 was 0.39 mg/kg and the ED95 was 0.56 mg/kg. No significant adverse events were observed, and heart rate and blood pressure remained stable during induction. These doses serve as initial references for pediatric intubation without muscle relaxants.
In a mouse model of depression created by spared nerve injury, esketamine improved depression-like behaviors, such as increasing time spent in open arms and central area of an open field test and total distance traveled, while also increasing immobility in forced swimming and tail suspension tests. It raised the density of total and mature dendritic spines in the prefrontal cortex and increased expression of CRMP2 and PSD-95 proteins. These findings suggest esketamine promotes brain plasticity in the prefrontal cortex, possibly through changes in these proteins.