BACKGROUND: Dexmedetomidine (DEX), a highly selective α2-adrenergic receptor agonist, is widely used for sedation and anesthesia in patients undergoing hepatectomy. However, the effect of DEX on autophagic flux and liver regeneration remains unclear.
OBJECTIVE: This study aimed to determine the role of DEX in hepatocyte autophagic flux and liver regeneration after PHx.
METHODS: In mice, DEX was intraperitoneally injected 5 min before and 6 h after PHx. In vitro, DEX was co-incubated with culture medium for 24 h. Autophagic flux was detected by LC3-II and SQSTM1 expression levels in primary mouse hepatocytes and the proportion of red puncta in AML-12 cells transfected with FUGW-PK-hLC3 plasmid. Liver regeneration was assessed by cyclinD1 expression, Edu incorporation, H&E staining, ki67 immunostaining and liver/body ratios. Bafilomycin A1, si-GSK3β and Flag-tagged GSK3β, α2-ADR antagonist, GSK3β inhibitor, AKT inhibitor were used to identify the role of GSK3β in DEX-mediated autophagic flux and hepatocyte proliferation.
RESULTS: Pre- and post-operative DEX treatment promoted liver regeneration after PHx, showing 12 h earlier than in DEX-untreated mice, accompanied by facilitated autophagic flux, which was completely abolished by bafilomycin A1 or α2-ADR antagonist. The suppression of GSK3β activity by SB216763 and si-GSK3β enhanced the effect of DEX on autophagic flux and liver regeneration, which was abolished by AKT inhibitor.
CONCLUSIONS: Pre- and post-operative administration of DEX facilitates autophagic flux, leading to enhanced liver regeneration after partial hepatectomy through suppression of GSK3β activity in an α2-ADR-dependent manner.

UNASSIGNED: Postoperative pain is a common occurrence in pediatric patients following craniotomy, often leading to negative outcomes. Intravenous dexmedetomidine and lidocaine are commonly used adjuvant medicines in general anesthesia to reduce perioperative opioid consumption and relieve postoperative pain in adults. While they show promise for use in pediatrics, the evidence of their application in pediatric craniotomy patients is limited. Therefore, we aimed to compare the effects of dexmedetomidine and lidocaine on postoperative pain in pediatric patients following craniotomy.
UNASSIGNED: We conducted a randomized, double-blind, single-center trial on children scheduled for craniotomy. The 255 recruited participants aged 1-12 years were randomly assigned to intraoperatively receive a loading intravenous dose of either dexmedetomidine 1 μg·kg-1 or lidocaine 2 mg·kg-1 or normal saline for 15 min followed by dexmedetomidine 0.5 μg·kg-1·h-1 or lidocaine 1 mg·kg-1·h-1 or normal saline until the sutures of endocranium were completed. The primary outcome was the cumulative sufentanil consumption within 24 h post-surgery.
UNASSIGNED: A total of 241 patients were included in the statistical analysis. The primary outcome did not show any significant differences among the three groups (median (IQR) lidocaine group: 3.36 (1.32-5.64) μg vs. dexmedetomidine group: 3.12 (1.36-6.39) μg vs. control group 3.46 (1.77-7.62) μg, p = 0.485). Among the secondary outcomes, there was a statistically significant but small reduction in sufentanil consumption within 2 h, postoperative FLACC/WBFS/NRS pain scores within 4 h after surgery and postoperative Ramsay sedation scores in dexmedetomidine group (p < 0.05). Regarding postoperative complications, the incidence of electrolyte disturbance within 24 and 48 h after surgery was significantly higher in control group compared to the other two groups. There were no significant differences in intraoperative opioid consumption, postoperative frequency of remedy medication, or length of hospitalization among the three groups. No adverse events related to lidocaine or dexmedetomidine were observed.
UNASSIGNED: There were no significant differences in the primary outcome among the three groups. Although dexmedetomidine showed some benefits in reducing postoperative opioid consumption within the first 2 h and pain intensity within the first 4 h post-surgery, these findings should be interpreted with caution. Further research is required to comprehensively assess the outcomes and determine the optimal administration strategy.
UNASSIGNED: [http://www.chictr.org.cn/index.aspx], identifier [ChiCTR1800019411].

OBJECTIVE: To investigate the protective effect of dexmedetomidine (DEX) against erastin-induced ferroptosis in human renal tubular epithelial cells (HK-2 cells) and explore the underlying mechanism.
METHODS: HK-2 cells were treated with erastin alone or in combination with different concentrations (2.5, 5.0 and 10 μmol/L) of DEX, and the changes in cell viability were observed using CCK-8 assay. To explore the mechanism by which DEX inhibits erastin-induced ferroptosis, HK-2 cells were treated with erastin, erastin+10 μmol/L DEX, or erastin+10 μmol/L DEX+ML385 (a Nrf2 inhibitor), after which the cell viability was assessed. The level of intracellular Fe2+ was detected by cell ferrous iron colorimetric assay kit, and flow cytometry was performed to detect reactive oxygen species (ROS); MDA and reduced glutathione assay kits were used to detect the contents of MDA and GSH in the cells; The expressions of Nrf2, HO-1 and GPX4 proteins were detected by Western blotting.
RESULTS: Erastin treatment significantly inhibited the viability of the cells, decreased GSH content, and increased intracellular levels of Fe2+, ROS and MDA. The combined treatment with 10 μmol/L DEX markedly increased the viability of the cells, increased GSH content, reduced the levels of Fe2+, ROS and MDA, and upregulated the protein expressions of Nrf2, HO-1 and GPX4 in the cells. The application of ML385 obviously blocked the protective effect of DEX and caused significant inhibition of the Nrf2/HO-1/GPX4 pathway, decreased the cell viability and GSH content, and increased the levels of Fe2+, ROS and MDA in HK-2 cells.
CONCLUSIONS: The protective effect of DEX against erastin-induced ferroptosis of HK-2 cells is probably mediated by activation of the Nrf2/HO-1/GPX4 pathway to inhibit oxidative stress.

Our objective is to explore the protective effect of Dexmedetomidine on brain apoptosis and its mechanism through TREK-1 pathway. Forty male Sprague-Dawley rats were allocated into four groups: Sham, Cerebral Ischemia/Reperfusion Injury (CIRI), 50 µg/kg Dex, and 100 µg/kg Dex. A rat model of middle cerebral artery occlusion (MCAO) was employed to simulate cerebral embolism. Primary cortical neurons were exposed to Dex for 48 h, with some receiving additional treatment with 100 µM yohimbine hydrochloride (YOH) or TREK-1 small interfering RNA (siRNA). Neuronal damage was assessed using hematoxylin and eosin (HE) staining. Cell viability and apoptosis were measured by Cell Counting Kit-8 (CCK8) and flow cytometry, respectively. Protein and gene expression levels of Bcl-2, Bax, and TREK-1 were determined by Western blot and real-time polymerase chain reaction (PCR). Histopathological changes revealed that Dex treatment at both 50 µg/kg and 100 µg/kg significantly mitigated neuronal damage compared to the CIRI group. YOH treatment and Trek1 siRNA significantly reduced cell viability (p < 0.05). The mRNA expression and protein levels of TREK-1 and Bax were remarkably increased, while mRNA expression and protein levels of Bcl-2 was seriously decreased after CIRI modeling. In contrast, Dex treatment at both concentrations led to decreased TREK-1 and Bax expression and increased Bcl-2 expression in primary cortical neurons. Addition of 100 µM YOH and Trek1 siRNA reversed the effects of Dex on apoptosis-related genes (p < 0.05). Dex exerts neuroprotective effects through the TREK-1 pathway in vivo and in vitro.

BACKGROUND: Anesthetic-induced immunosuppression is of particular interest in tumor surgery. This study aimed to investigate the influence of the 4 most common general anesthetic techniques on immune function in patients undergoing flap reconstruction for oral cancer.
METHODS: 116 patients were randomly divided into 4 groups. Patients in group S were given sevoflurane-based anesthesia. Group P was administered propofol-based anesthesia. The SD group received sevoflurane combined with dexmedetomidine anesthesia. The propofol combined with dexmedetomidine anesthesia (PD) group received PD. Blood samples were obtained at 5 time points: baseline (T0), 1 hour after the start of the operation (T1), end of the operation (T2), 24 hours (T3), and 48 hours (T4) after the operation. Lymphocyte subsets (including CD3+, CD4+, CD8+, and B lymphocytes) and dendritic cells were analyzed by flow cytometry. Blood glucose, norepinephrine, and cortisol levels were measured using ELISA and a blood gas analyzer respectively.
RESULTS: In total, 107 patients were included in the final analysis. Immunological indicators, except CD8+ counts, were all decreased in groups S, P, and SD at T1-4 compared with the baseline value, and the counts of CD3+, CD4+, and dendritic cells, as well as CD4+/CD8+ ratios, were significantly higher in the PD group than in the S, P, and SD at T1-3 (P < .05). There were no significant differences between groups P and SD at any observation time point. Intraoperative stress indices, including norepinephrine and cortisol levels, were significantly lower in the PD group than in the other 3 groups at T1-2 (P < .05).
CONCLUSIONS: These findings suggest that PD as a probably optimal choice can alleviate immunosuppression in patients undergoing flap reconstruction for oral cancer.

UNASSIGNED: This study aimed to investigate the effect of different doses of dexmedetomidine combined with sufentanil on postoperative analgesia in developmental hip dislocation in children after Salter osteotomy.
UNASSIGNED: The clinical data of 98 children with developmental hip dislocation, who underwent Salter osteotomy in our center between January 2020 and February 2023, were selected. The children were randomly divided into four groups based on the application of patient-controlled intravenous analgesia (sufentanil + granisetron ± dexmedetomidine). All children received 1 µg/kg/day of sufentanil and 3 mg of granisetron. Group A did not receive dexmedetomidine, and Groups B, C, and D received 0.5, 0.75, and 1.0 µg/kg/day of dexmedetomidine, respectively. The pain indicators and immune factor levels of children in each group were compared.
UNASSIGNED: The heart rate (HR) and respiratory rate (RR) 2 h after operation in Groups C and D were significantly lower than those in Groups A and B (P < 0.05). The pain scores decreased over time after treatment in all groups. When compared at the same time point, children in Group D had the lowest pain scores, which were significantly lower than the other three groups (P < 0.05). The total consumption of sufentanil in Groups C and D was significantly lower than that in Group A (P < 0.05). On the first day after surgery, the children in Group D had lower levels of serum adrenocorticotropic hormone, interleukin-6, and corticosterone than those in Group A (P < 0.05).
UNASSIGNED: Administration of 1.0 µg/kg/day of dexmedetomidine combined with sufentanil in intravenous controlled analgesia after Salter osteotomy for developmental hip dislocation in children has a better analgesic effect, less consumption of sufentanil, and low incidence of opioid adverse reactions.

BACKGROUND: Use of sedatives and analgesics is associated with the occurrence of delirium in critically ill patients receiving mechanical ventilation. Dexmedetomidine reduces the occurrence of delirium but may cause hypotension, bradycardia, and insufficient sedation. This substudy aims to determine whether the combination of esketamine with dexmedetomidine can reduce the side effects and risk of delirium than dexmedetomidine alone in mechanically ventilated patients.
METHODS: This single-center, randomized, active-controlled, superiority trial will be conducted at The First Affiliated Hospital of Nanjing Medical University. A total of 134 mechanically ventilated patients will be recruited and randomized to receive either dexmedetomidine alone or esketamine combined with dexmedetomidine, until extubation or for a maximum of 14 days. The primary outcome is the occurrence of delirium, while the second outcomes include the number of delirium-free days; subtype, severity, and duration of delirium; time to first onset of delirium; total dose of vasopressors and antipsychotics; duration of mechanical ventilation; ICU and hospital length of stay (LOS); accidental extubation, re-intubation, re-admission; and mortality in the ICU at 14 and 28 days.
CONCLUSIONS: There is an urgent need for a new combination regimen of dexmedetomidine due to its evident side effects. The combination of esketamine and dexmedetomidine has been applied throughout the perioperative period. However, there is still a lack of evidence on the effects of this regimen on delirium in mechanically ventilated ICU patients. This substudy will evaluate the effects of the combination of esketamine and dexmedetomidine in reducing the risk of delirium for mechanically ventilated patients in ICU, thus providing evidence of this combination to improve the short-term prognosis. The study protocol has obtained approval from the Medical Ethics Committee (ID: 2022-SR-450).
BACKGROUND: ClinicalTrials.gov: NCT05466708, registered on 20 July 2022.

The potential long-term effects of anesthesia on cognitive development, especially in neonates and infants, have raised concerns. However, our understanding of its underlying mechanisms and effective treatments is still limited. In this study, we found that early exposure to isoflurane (ISO) impaired fear memory retrieval, which was reversed by dexmedetomidine (DEX) pre-treatment. Measurement of c-fos expression revealed that ISO exposure significantly increased neuronal activation in the zona incerta (ZI). Fiber photometry recording showed that ZI neurons from ISO mice displayed enhanced calcium activity during retrieval of fear memory compared to the control group, while DEX treatment reduced this enhanced calcium activity. Chemogenetic inhibition of ZI neurons effectively rescued the impairments caused by ISO exposure. These findings suggest that the ZI may play a pivotal role in mediating the cognitive effects of anesthetics, offering a potential therapeutic target for preventing anesthesia-related cognitive impairments.

Dexmedetomidine (Dex) is widely used in the sedation in intensive care units and as an anesthetic adjunct. Considering the anti-inflammatory and antioxidant properties of Dex, we applied in vivo rat model as well as in vitro cardiomyocyte models (embryonic rat cardiomyocytes H9c2 cells and neonatal rat cardiomyocytes, NRCMs) to evaluate the effects of Dex against myocardial ischemia reperfusion (I/R) injury. Transcriptomic sequencing for gene expression in heart tissues from control rats and Dex-treated rats identified that genes related to fatty acid metabolism were significantly regulated by Dex. Among these genes, the elongation of long-chain fatty acids (ELOVL) family member 6 (Elovl6) was most increased upon Dex-treatment. By comparing the effects of Dex on both wild type and Elovl6-knockdown H9c2 cells and NRCMs under oxygen-glucose deprivation/reoxygenation (OGD/R) challenge, we found that Elovl6 knockdown attenuated the protection efficiency of Dex, which was supported by the cytotoxicity endpoints (cell viability and lactate dehydrogenase release) and apoptosis as well as key gene expressions. These results indicate that Dex exhibited the protective function against myocardial I/R injury via fatty acid metabolism pathways and Elovl6 plays a key role in the process, which was further confirmed using palmitate exposure in both cells, as well as in an in vivo rat model. Overall, this study systematically evaluates the protective effects of Dex on the myocardial I/R injury and provides better understanding on the fatty acid metabolism underlying the beneficial effects of Dex.

OBJECTIVE: We conducted this double-blinded randomized controlled trial to examine whether the combination of dexamethasone and dexmedetomidine as adjuvants of transversus abdominis plane (TAP) block could improve analgesia efficacy and duration for gastric cancer patients.
METHODS: Randomized controlled trial.
METHODS: The preoperative area, operating room, postanesthesia recovery room and bed ward.
METHODS: A total of 312 adult patients (104 per group) with gastric cancer were included.
METHODS: Patients received bilateral subcostal TAP block with three different anesthetics (60 ml 0.25% ropivacaine added with 10 mg dexamethasone and 1 μg·kg-1 dexmedetomidine [A] or 10 mg dexamethasone [B] or 1 μg·kg-1 dexmedetomidine [C]).
METHODS: The primary outcome was the incidence of moderate-to-severe pain 24 h on movement. Secondary outcomes included incidence of moderate-to-severe pain, pain score, opioids use, recovery quality and adverse events.
RESULTS: The incidence of moderate-to-severe pain on movement 24 h postoperatively of group A was significantly lower than group B (45.19% vs 63.46%; RR 0.71; 95% CI, 0.55 to 0.92) and group C (45.19% vs 73.08%, RR 0.62; 95% CI, 0.49 to 0.79). The median moving pain scores decreased significantly at 24 h (3.00 [3.00,5.00] vs 4.00 [3.00,6.00] vs 4.00 [3.00,5.00]; P < 0.001). There were significant differences in the opioids consumption within the first 24 h (27.5 [17.0,37.2] vs 30.0 [20.0,42.0] vs 32.0 [25.0,44.0] mg; P = 0.01) and the duration to first rescue analgesia (65.5 ± 26.7 vs 45.9 ± 34.5 vs 49.2 ± 27.2 h; P = 0.04).
CONCLUSIONS: The combination with dexamethasone and dexmedetomidine as adjuvants for TAP block reduced the incidence of moderate-to-severe pain and pain score both on movement and at rest at 24 h with prolonged duration to first rescue analgesia after gastric cancer surgery.
BACKGROUND: ChiCTR2000037981.