AIM:To observe the effect of opioid-free anesthesia with esketamine on delirium after hip replacement surgery in elderly patients.METH-ODS:One hundred and fourteen elderly patients who underwent hip replacement were randomly di-vided into two groups:opioid-free anesthesia(OFA)group and opioid anesthesia(OA)group(n=57).During anesthesia induction and maintenance,es-ketamine was administered in OFA group,and that fentanyl and remifentanil were administered in OA group.Delirium was mainly recorded within 3 days after the surgeries,and the patients'delirium sta-tus was evaluated using the Chinese Revised Deliri-um Diagnostic Scale(CAM-CR).RESULTS:The pa-tients in OFA group had lower CAM-CR scores and delirium incidence compared to those in the OA group at 2 days after surgery.CONCLUSION:Opioid-free anesthesia based on esketamine can effective-ly reduce delirium after hip replacement in elderly patients.

AIM:To investigate the impact of es-ketamine-mediated opioid-free anesthesia(OFA)on postoperative gastrointestinal function in patients undergoing laparoscopic distal gastrectomy for gas-tric cancer.METHODS:A total of 150 pa-tients,scheduled for elective laparoscopic distal gas-trectomy for gastric cancer and meeting the inclu-sion and exclusion criteria,were randomly assigned to either the OFA group or the opioid-based anes-thesia(OBA)group using a random number ta-ble,with 75 patients in each group.The OFA group was administered an anesthesia regimen pri-marily consisting of esketamine,while the OBA group received conventional opioid anesthesia,pri-marily consisting of sufentanil and remifentanil.The primary outcome measure was postoperative flatus time,defined as the interval from the end of sur-gery to the first passage of gas.RESULTS:The OFA group exhibited a shorter postoperative flatus time compared to the OBA group(P＜0.01).Intraopera-tive blood loss and norepinephrine consumption were significantly less in the OFA group compared to the OBA group(P＜0.05);the postoperative HADS-D score was better in the OFA group than in the OBA group,and both the OFA and OBA groups showed significantly lower postoperative HADS-A and HADS-D scores compared to their preoperative levels(P＜0.05);the incidence rate of abdominal distension was significantly lower in the OFA group compared to the OBA group(P＜0.05).CONCLUSION:The use of esketamine-mediated opioid-free anesthesia can expedite gastrointestinal function recovery,reduce hospital stay duration,and decrease postoperative adverse reactions in patients undergoing laparo-scopic distal gastrectomy for gastric cancer.

AIM:To investigate the impact of es-ketamine-mediated opioid-free anesthesia(OFA)on postoperative gastrointestinal function in patients undergoing laparoscopic distal gastrectomy for gas-tric cancer.METHODS:A total of 150 pa-tients,scheduled for elective laparoscopic distal gas-trectomy for gastric cancer and meeting the inclu-sion and exclusion criteria,were randomly assigned to either the OFA group or the opioid-based anes-thesia(OBA)group using a random number ta-ble,with 75 patients in each group.The OFA group was administered an anesthesia regimen pri-marily consisting of esketamine,while the OBA group received conventional opioid anesthesia,pri-marily consisting of sufentanil and remifentanil.The primary outcome measure was postoperative flatus time,defined as the interval from the end of sur-gery to the first passage of gas.RESULTS:The OFA group exhibited a shorter postoperative flatus time compared to the OBA group(P＜0.01).Intraopera-tive blood loss and norepinephrine consumption were significantly less in the OFA group compared to the OBA group(P＜0.05);the postoperative HADS-D score was better in the OFA group than in the OBA group,and both the OFA and OBA groups showed significantly lower postoperative HADS-A and HADS-D scores compared to their preoperative levels(P＜0.05);the incidence rate of abdominal distension was significantly lower in the OFA group compared to the OBA group(P＜0.05).CONCLUSION:The use of esketamine-mediated opioid-free anesthesia can expedite gastrointestinal function recovery,reduce hospital stay duration,and decrease postoperative adverse reactions in patients undergoing laparo-scopic distal gastrectomy for gastric cancer.

AIM:To observe the effect of opioid-free anesthesia with esketamine on delirium after hip replacement surgery in elderly patients.METH-ODS:One hundred and fourteen elderly patients who underwent hip replacement were randomly di-vided into two groups:opioid-free anesthesia(OFA)group and opioid anesthesia(OA)group(n=57).During anesthesia induction and maintenance,es-ketamine was administered in OFA group,and that fentanyl and remifentanil were administered in OA group.Delirium was mainly recorded within 3 days after the surgeries,and the patients'delirium sta-tus was evaluated using the Chinese Revised Deliri-um Diagnostic Scale(CAM-CR).RESULTS:The pa-tients in OFA group had lower CAM-CR scores and delirium incidence compared to those in the OA group at 2 days after surgery.CONCLUSION:Opioid-free anesthesia based on esketamine can effective-ly reduce delirium after hip replacement in elderly patients.

Topical anesthesia are being widely used in clinical diagnostic or therapeutic fields such as ophthalmology, ENT, dermatology, urology. It is defined as superficial loss of sensation in mucous membranes or skin, produced by direct application of penetrating local anesthetics. Topical anesthesia has the advantages of simple performance, high safety, quick recovery, which can effectively improve patient's satisfaction. In recent years, more and more attention has been paid to the concept of comfortable diagnosis and treatment. The new drugs and application methods of topical anesthesia are emerging constantly, special attention must be paid to their pharmacological characteristics and possible adverse reactions when using them. This article reviews the research progress of topical anesthesia in clinical application in order to provide reference for clinical practice.

Cognitive dysfunction has become a pivotal factor affecting the quality of life of elderly patients. The existing literatures can not explain the factors causing cognitive decline. Many researchers believe that anesthetics and analgesics may play important roles in cognitive dysfunction. This review will discuss the effects of different anesthetics and analgesics on cognitive function and briefly describe their mechanisms, so as to provide reference for the rational choice of medications in clinical practice.

Depression has become a serious global public health problem due to its high incidence and great harm, and has aroused the attention of the society. Ketamine, a commonly used intravenous anesthetic and analgesic in clinical practice, has been found to have unique advantages in antidepressant therapy in recent years. With the development of research, the enantiomeric isomers of ketamine, (S)-ketamine and (R)ketamine have entered the research field of antidepressant therapy. In this paper, we reviewed the progress of research on the antidepressant effects and mechanisms of ketamine, (S )-ketamine and (R)-ketamine, and provide a brief overview of the antidepressant effects of metabolites of ketamine, thereby deepening the understanding of the readers in the field of antidepressant effects of ketamine.

Objective To investigate the effect of dexmedetomidine on cardiac conduction system at different loading doses.Methods Eighty male patients with orthopedic surgery,aged 20-65 years,falling into ASA physical atatus Ⅰ or Ⅰ,were randomly divided into groups D1,D2,D3 and C with 20 in each.Groups D1,D2 and D3 were infused with dexmedetomidine 0.3,0.5 and 0.8μg/ kg using a micro-pump for 10 min,group C infused 0.9％ NaCl solution in the same manner.MAP,HR,SpO2 were recorded and ECG was traced before injection (T1),5 min (T2),10 min (T3) after injection and 10 min after the end of pumping (T4).P wave duration,P-R interval,QRS time,and QTc value were calculated.Results There was no significant difference in SpO2,P wave duration,P R interval and QRS time among the four groups.There was no significant difference in MAP,HR and QTc value in group C and group D1.Compared with that in group C,MAP was significantly decreased,HR was significantly slowed down and QTc value was significantly shortened in group D2 and D3 from T2 to T4 (P ＜ 0.05).Conclusion Dexmedetomidine does not affect the cardiac conduction system.0.5 μg/kg and 0.8μg/kg dexmedetomidine can effectively shorten the QT interval.To avoid severe bradycardia,patients with low heart rate should use no more than 0.5 μg/kg dexmedetomidine.

Objective To investigate the role and underlying mechanism of dexmedetomidine in protecting mouse neuroblastoma N2a cells against oxidative stress injury,and to discuss the effect of ERK signaling pathway.Methods Na2 cell oxidative stress injury model was established by H2O2 treatment.Cells were divided into 5 groups:control group (group C),H2O2group (group H), dexmedetomidine group (group D),H2O2+dexmedetomidine group (group HD),H2O2+dexme-detomidine+ERK inhibitor group (group HDP).Group H,group HD and group HDP were given 200 μmol/L H2O2with or without 100 ng/ml dexmedetomidine and 20 μmol/L ERK inhibitor PD98059,group D was treated with dexmedetomidine at the corresponding point,group C was treated with equal normal saline,After 1,4 hours of H2O2stimulation,cell survival,morphology changes,SOD production and ERK intracellular signaling pathway were compared between groups. Results Compared to group C,N2a cells in the group H demonstrated significantly ruduced cell sur-vival,much worse cell morphology and less SOD production (P<0.05).Compared to group H,N2a cells in group HD demonstrated significantly increased cell survival,much better preserved cell mor-phology,higher levels of SOD and enhanced ERK activation (P<0.05);Compared to group HD, cells in the group HDP had markedly decreased cell survival,worse cell morphology and lower SOD level (P<0.05).No significant changes were found in cell survival,morphology changes,SOD pro-duction and ERK intracellular signaling pathway between the groups C and D.Conclusion Dexme-detomidine protected mouse neuroblastoma N2a cells against oxidative stress injury by regulating ERK activation and SOD production.

Objective To explor the safty and the effect of controlled intravenous analgesia with remifentanil on hyoxemia in obese patients with painless gastroscopy.Methods One hundred patients undergoing painless gastroscopy were randomly and equally allocated into 2 groups(50 each).In group R,anesthesia was induced with TCI(target-controlled infusion) of remifentanil,and the target plasma concentration (Cp) of propofol was set at 2ng/ml.In group N,the same volume of saline was continues infusion.MAP,RR and HR were monitored and recorded before the examination(T0),the time point of examination start(T1),gastroscopy go through glottis(T2),at the end of the operation (T3) and 5 min after examination (T4).The effect of sedation was evaluated by Ramsay.Except that,gastroscopy time,the satisfaction of patient,anesthetist and endoscopist were recored.In addition,apnea,bradycardia,hypoxemia,myoclonus,body movement,hypotension and postoperative complications were also recorded.Results Compared with group N,in group R,HR,MAP and rate of body movement were significantly decreased (P ＜ 0.05).Except that,the satisfaction of patient and endoscopist were increased (P ＜ 0.05).Conclusion TCI of remifentanil can provide satisfaction sedation for obese patients with painless gastroscopy with few adverse effects.