Circular RNAs (circRNAs) are abundant in the central nervous system and linked to depression. In a mouse model of depression (chronic unpredictable mild stress), a single intravenous dose of esketamine (5 mg/kg) reduced the expression of circKat6b in hippocampal astrocytes. Overexpressing circKat6b in the hippocampus weakened esketamine's antidepressant effects. Molecular analyses revealed that circKat6b overexpression increased stat1 and p-stat1 expression in astrocytes, and reversed esketamine's suppression of p-stat1. The findings suggest esketamine's antidepressant action may involve lowering circKat6b in hippocampal astrocytes.
Ketamine compared with other sedatives during rapid sequence intubation (RSI) in critically ill patients shows no significant difference in in-hospital mortality, physiological function, or adverse events. A systematic review and meta-analysis of 15 studies (5 randomized controlled trials and 10 cohort studies) involving 16,807 participants found no overall mortality benefit (odds ratio 0.90, 95% confidence interval 0.72 to 1.12). Low-quality evidence suggests ketamine may reduce mortality within the first seven days of hospitalization (odds ratio 0.42, 95% confidence interval 0.19 to 0.93) but may also prolong intensive care unit stay (mean difference -0.71 days free of ICU at day 28, 95% confidence interval -1.38 to -0.05).