Perioperative Neurocognitive Disorders

Esketamine is a common anesthetic adjuvant. Previous studies have shown that it may have protective effects on the brain. This study aims to investigate whether esketamine can improve cognitive function recovery in elderly patients (aged 60 years and older) undergoing oral and maxillofacial surgery. Participants will be randomly assigned to receive either esketamine or a placebo (normal saline) during anesthesia. Neither the participants nor the researchers will know which treatment is given. Cognitive function will be assessed using standardized tests before surgery and at 1, 3, 7, and 15 days after surgery. Sleep quality, pain scores, emotional status, and adverse events will also be recorded. Blood samples will be collected to explore potential mechanisms. The study is expected to enroll approximately 98 participants at the Third Affiliated Hospital of Air Force Medical University in Xi'an, China. Participation will last about 16 days from the day before surgery to the final follow-up on day 15 after surgery.

The term perioperative neurocognitive disorders (PND) is derived from postoperative cognitive dysfunction (POCD), and has been renamed as PND in recent years in accordance with the latest international consensus. PND specifically refers to changes in mental, social and cognitive abilities in patients following surgery; in severe cases, personality changes and reduced social functioning may also occur. As a serious complication affecting the central nervous system (CNS), apart from surgical trauma, advanced age is widely recognized as a critical factor contributing to the development and progression of PND. Its adverse effects represent a major challenge for the rapidly growing elderly population worldwide. It is currently believed that the decline in cognitive functions such as memory and attention observed in some patients after surgery may be associated with inflammatory responses in the brain. Surgical stress may activate supporting cells in the brain, such as astrocytes. When these cells are abnormally activated, they may fail to maintain normal neuronal function, thereby disrupting brain homeostasis and leading to cognitive impairment. Recent studies have shown that these glial cells exert distinct effects on neurons under different phenotypes: some phenotypes promote neural repair and protection, whereas others exacerbate neural injury. Evidence suggests that in multiple neurological disorders, the pro-inflammatory phenotype of glial cells is closely associated with cognitive impairment. Prokineticin-2 (PK2) is an endogenous signaling molecule involved in the regulation of diverse physiological processes, including inflammatory responses, energy metabolism, and neuroprotection. Previous studies have demonstrated that PK2 exerts protective effects in various neurological disease models, improving neuronal function and alleviating cognitive or motor deficits. Our preliminary animal experiments revealed reduced brain PK2 levels, especially in memory-related regions, in mice with postoperative cognitive dysfunction. Exogenous supplementation of PK2 significantly restored brain cell function and improved cognitive performance in these mice, suggesting that PK2 may play an important role in maintaining cerebral function after surgery. However, it remains unclear whether changes in PK2 levels in clinical patients correlate with the occurrence and severity of postoperative cognitive dysfunction. This study aims to investigate changes in circulating PK2 levels and explore their association with postoperative cognitive alterations, so as to provide evidence for the improved prevention and identification of PND. We plan to enroll elderly patients undergoing hip replacement surgery at Nanjing First Hospital. By analyzing PK2 expression levels and dynamic changes, combined with postoperative neuropsychological scale assessments, we will evaluate the correlation between serum PK2 levels and the clinical incidence of PND, and further verify the intrinsic link between PK2 levels and the pathogenesis of PND.

Neurocognitive complications, mainly delirium and neurocognitive disorders, are common cerebral complications in older patients after surgery and associated with worse outcomes. In previous studies, perioperative use of dexmedetomidine-esketamine combination improved analgesia and sleep quality after surgery. Perioperative use of transcranial direct current stimulation (tDCS) also improved sleep quality and reduced delirium occurrence early after surgery. This 2×2 factorial trial is designed to investigate the effects of perioperative dexmedetomidine-esketamine combination and tDCS on early postoperative neurocognitive recovery and delirium occurrence in older patients.

To explore the predictive value of Electroencephalography features in Perioperative Neurocognitive Disorders in patients undergoing cardiovascular surgery under general anesthesia

This study aims to assess the association between perioperative cognitive function and postoperative quality of recovery.

Perioperative neurocognitive disorders is a common postoperative complication in elderly surgical patients. The role of gut microbiota in cognitive function has been concerned in recent years. Studies suggests that gastrointestinal surgery may affect the gut microbiota, and the effect varies between surgical procedures. In this study, the investigators will compare the differences of gut microbiota between total gastrectomy and double-tract reconstruction, to investigate the effect of gastric acid on the gut microbiota colonizing, and the effect of different surgical procedures on the postoperative cognitive function of proximal gastric cancer patients.