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Effect of esketamine on postoperative delirium in general anesthesia patients undergoing elective surgery: a meta-analysis of randomized controlled trials

BMC Anesthesiology volume 24, Article number: 442 (2024) Cite this article

Abstract

Background

Postoperative delirium is a common neurological complication, especially in older patients undergoing surgery, which is closely related to the poor prognosis of patients. The objective was to investigate the effects of esketamine on postoperative delirium in patients with general anesthesia.

Methods

The databases of PubMed, Embase, Cochrane Library and the Chinese National Knowledge Infrastructure were searched for all available randomised controlled trials on the effects of esketamine induction on postoperative delirium in patients undergoing elective general anesthesia from inception until April 21, 2024. We used RevMan5.4 software for data analysis. Dichotomous data was analyzed by risk ratios(RR) with a 95% confidence interval(CI), and continuous data by mean differences(MD). We also evaluated the risk of literature bias using the Cochrane Bias Risk Assessment tool.

Results

We included a total of 17 randomized controlled trials, including 1286 patients undergoing elective general anesthesia. In 17 studies, esketamine significantly reduced the incidence of postoperative delirium (RR: 0.43; 95%CI: 0.33 ~ 0.57; p < 0.001). Five studies examined the incidence of postoperative adverse events (nausea, vomiting, dizziness and resporatory depression) and showed no statistically significant difference between the esketamine group and the control group (normal saline or dexmedetomidine) (RR: 0.82; 95%CI: 0.65 ~ 1.03; p = 0.08). In addition, this study found that the esketamine group had a lower incidence of hypotension (RR: 0.24; 95%CI: 0.12 ~ 0.48; p < 0.001) and a lower score on the visual analogue scale 24 h after surgery (MD: -0.44; 95%CI: -0.54 ~ -0.33; p < 0.001).

Conclusion

According to our meta-analysis, the use of esketamine during anesthesia induction significantly reduced the incidence of postoperative delirium in patients undergoing elective general anesthesia without increasing the incidence of postoperative adverse reactions.

Peer Review reports

Introduction

Delirium is a cognitive disturbance characterised by acute and fluctuating impairment in attention and awareness. Postoperative delirium (POD) usually arises between postoperative days 2–5 [1]. POD is more frequent with increasing age, occurring in up to 65% of older patients [2]. In addition, POD is considered a strong predictor of delayed neurocognitive recovery [3]. Postoperative delirium and delayed neurocognitive recovery have been associated with higher odds of mortality, postoperative complications, unplanned intensive care unit admissions, length of hospital stay, and increased healthcare resource expenditure [4, 5]. There are several factors that contribute to POD, including patient characteristics, anesthetic and operation factors, and postoperative factors. Advanced age, preoperative cognitive dysfunction, long-term use of multiple drugs, multiple co-existing diseases, long duration of anesthesia, postoperative infection, and respiratory problems are all considered as risk factors for POD [6].

Ketamine is an intravenous anesthetic with both sedative and analgesic effects. The nonanesthetic action of ketamine represents an innovative approach for its clinical application, but its use for POD prophylaxis remains disputed. Studies have demonstrated that the administration of sub-anesthetic dose of ketamine (0.2–0.5 mg/kg) during anesthesia induction can reduce the occurrence of neurocognitive disorders to some extent, although the preventative effect on POD is unknown [7]. Two recent systematic reviews have shown that intraoperative ketamine does not reduce the incidence of POD or neurocognitive disorders [8, 9]. As can be observed, the usefulness of intraoperative ketamine usage for avoiding POD or neurocognitive disorders requires more research.

Esketamine is an optically active isomers of ketamine [10]. Its action site is similar to ketamine, mainly N-methyl-D aspartic acid receptor, but it has an enhanced affinity than ketamine, a stronger analgesic effect, a higher clearance rate in vivo, and a lower incidence of side effects [11]. However, at present, the relevant clinical evidence of esketamine is limited, and the effect of esketamine on POD unclear. Therefore, we conducted this study to investigate the effects of esketamine on postoperative delirium in patients with general anesthesia.

Methods

The article was finished in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis Statement guidelines. The study protocol was registered in PROSPERO (CRD42024549036).

Search strategy

We systematically searched the databases of PubMed, Embase, Cochrane Central Registry of Controlled Trials and the Chinese National Knowledge Infrastructure for all relevant studies from inception to March 17, 2024. The search strategy in PubMed was as follows: (("delirium"[MeSH Terms] OR "delirium"[All Fields] OR ("Postoperative Cognitive Complications"[MeSH Terms] OR "Postoperative Cognitive Complications"[All Fields])) AND ("esketamine"[MeSH Terms] OR "esketamine"[All Fields])). The search strategy was limited to randomized controlled trials (RCTs) and participants were restricted to adults.

Study selection

The inclusion criteria were: (1) studies examining the association between esketamine vs. control and delirium under general anesthesia; (2) studies must be a randomized controlled trial. (3) articles are journal articles. (4) articles were available in English and Chinese only. The exclusion criteria were: (1) the participants were children; (2) studies were spinal anesthesia; (3) the full text was not available. (4) dissertations were not included.

Study endpoints

The primary outcome was the incidence of POD, and the secondary outcomes were incidence of adverse reactions, blood pressure after induction, and visual analogue scale scores(VAS) 24 h after surgery. Adverse reactions included nausea, vomiting, dizziness, and respiratory depression.

Data extraction and quality assessment

Data extraction was done by two people. One evaluator completed the data extraction, while the other validated it independently. The main information of included studies was extracted, such as first author, year of publication, interventions, type of operation, sample size, age range, Grade of ASA, the administration of esketamine, outcome measures and the assessment methods for POD. The extracted literature information was shown in Table 1. We assessed the risk of bias using tools recommended in the Cochrane Manual, including randomization, assignment concealment, blind implementation, outcome data, selective reporting results, and other sources of bias. The risk deviation diagram of the included literature is shown in Fig. 2. Finally, publication bias was assessed by examining funnel plots (Fig. 9) and a sensitivity analysis was performed to evaluate the stability of the results (Fig. 10).

Table 1 The information and characteristics of studies
Full size table

Statistical analysis

For processing and analysis, RevMan5.4 statistical software was utilized. Relative hazard ratio (RR) and 95% confidence interval (CI) were used to calculate dichotomous variables. For the purpose of expressing continuous variables, the means difference (MD) and its 95% confidence interval (CI) are utilized. To ascertain the heterogeneity among the analyzed studies, the I2 statistic and Q tests were implemented. Heterogeneity was graded according to Cochrane guidelines: I2 < 25% was low heterogeneity, 25–50% was moderate heterogeneity, 50–75% was substantial heterogeneity, and > 75% was considerable heterogeneity. This determined whether we used a fixed effect model or a random effect model to analyze the data. When P > 0.1 or I2 ≤ 50%, it was considered that no significant heterogeneity existed in each study, and fixed effect model was selected for analysis. Otherwise, when P ≤ 0.1 and I2 > 50%, it was considered that there was significant heterogeneity among the studies, and we used the random effect model to conduct the analysis.

Results

Search results

The process of searching and including literature in the databases was illustrated in Fig. 1. We found 146 articles after searching various databases, and no articles found by other sources, and 100 of them were obtained after deleting duplicate entries. Following the abstract and title screens, 74 records were excluded. A total of 26 articles underwent a thorough full text review, but four articles were excluded because the full text could not be found, and five were excluded because no data was available. The PRISMA flow diagram of the included documents was shown in Fig. 1. Ultimately, 17 RCT studies were included, and the information and characteristics of the literature are presented in Table 1.

Fig. 1
figure 1

PRISMA flow diagram

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Characteristics of trials

The trials ultimately included in this meta-analysis were published between 2021 and 2024 and involved a total of 1286 patients (643 patients included in the esketamine group and 643 patients included in the control group). In our meta-analysis, 2 studies with 192 patients analyzed the effect of esketamine on postoperative delirium after cardiac surgery, and 15 studies containing of 1094 patients analyzed the association between esketamine and postoperative delirium in non-cardiac surgery patients. Table 1 provided a detailed description of the included trials.

Risk of bias in included studies

We evaluated 17 RCTS using the Cochrane risk-of-bias Tool [12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28]. Three trials were judged to be of “some concern”, ten trials were judged to be of “low risk of bias”, and four were judged to be of “high risk of bias” (Fig. 2A and B).

Fig. 2
figure 2

A The Risk of bias in included studies. B Quality assessment of each study included in the meta-analysis

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Meta‐analysis for the studies of outcomes

POD

There were 17 studies with a total of 1286 patients with POD incidence, and there was no statistical heterogeneity among the studies (P = 0.81, I2 = 0%). The fixed-effect model was used for analysis, and it was found that the use of esketamine was significantly associated with the incidence of postoperative delirium compared with the control group (RR: 0.43; 95%CI: 0.33 ~ 0.57; p < 0.001) (Fig. 3). Correspondingly, the intraoperative administration of esketamine had a protective effect against postoperative delirium, reducing the risk of postoperative delirium by 57%.

Fig. 3
figure 3

Esketamine versus control group for postoperative delirium

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Secondary outcomes

Five studies examined the incidence of postoperative adverse events [12, 16, 17, 20, 27], including nausea and vomiting, dizziness and respiratory depression. The results of our analysis showed no statistically significant difference in the incidence of adverse reactions between the esketamine group and the control group (RR: 0.80; 95%CI: 0.48 ~ 1.33; p = 0.39) (Fig. 4).

Fig. 4
figure 4

Esketamine versus control group for adverse events

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Five studies recorded blood pressure after induction [12, 16, 18, 22, 23], three of which recorded the incidence of induced hypotension, and the analysis showed that the incidence of hypotension was significantly lower in the esketamine group than in the control group (RR: 0.24; 95%CI: 0.12 ~ 0.48; p < 0.001) (Fig. 5). Mean arterial pressure after induction was recorded in two studies, and analysis showed that mean arterial pressure was significantly higher in the esketamine group than in the control group (MD:7.28; 95%CI: 3.67 ~ 10.89; p < 0.001) (Fig. 6).

Fig. 5
figure 5

Esketamine versus control group for the incidence of hypotension

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Fig. 6
figure 6

Esketamine versus control group for MAP

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Four studies recorded VAS scores 24 h after surgery [13, 17, 22, 27] and found that the esketamine group had significantly lower VAS scores than the control group (MD: -0.44; 95%CI: -0.54 ~ -0.33; P < 0.001) (Fig. 7).

Fig. 7
figure 7

Esketamine versus control group for VAS

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Subgroup analysis

The studies on the incidence of POD were divided into two subgroups based on the age of patients. Ten studies were conducted with patients aged 60 years or older and four studies were tested with patients aged 18 years or older, and assessed the effect on POD. Notably, esketamine significantly reduced the POD prevalence regardless of age (Fig. 8).

Fig. 8
figure 8

Esketamine versus control group for subgroup analysis

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Publication bias and sensitivity analysis

We included a total of 17 studies, and funnel plots revealed a symmetrical distribution of these studies, indicating no publication bias (Fig. 9). In addition, we performed a sensitivity analysis and found that the results of the meta-analysis did not change significantly with changes in the number of studies, indicating that the overall outcome regarding POD remained robust (Fig. 10).

Fig. 9
figure 9

Funnel plot

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Fig. 10
figure 10

Sensitivity analysis

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Discussion

This study provides new evidence by conducting a comprehensive meta-analysis of published papers to determine the effect of esketamine on postoperative delirium. The results of this study demonstrated that esketamine can reduce the incidence of postoperative delirium in patients undergoing elective general anesthesia without increasing the incidence of postoperative adverse reactions. In addition, this study found that esketamine administration reduced the incidence of hypotension and VAS scores at 24 h after surgery.

The incidence of POD is 2–3% in the general surgery population, but it has been reported to occur in up to 50% to 70% of high-risk patient groups [29, 30]. POD has become an important issue in clinical practice because it has adverse effects on both early and long-term prognosis for patients. Therefore, the most critical method to reduce POD is prevention. Previous studies have shown that the use of preventive strategies can reduce the incidence of delirium by 40% in patients [31], however, these preventive strategies were non-drug preventive methods. Despite the lack of conclusive evidence for the application of medications to prevent POD, a number of medications have been investigated in clinical trials to observe their effects on POD, and esketamine is one of them.

Esketamine has multiple targets and exerts anesthetic and analgesic effects mainly through non-competitive antagonism of NMDA receptors. It also interacts with opioid and M-choline receptors, monoamine receptors, adenosine receptors, and other purine receptors [32]. Esketamine is widely used in clinic because of its many advantages, such as mild respiratory depression, anti-hyperalgesia, anti-inflammatory, reducing stress response, and activating cardiovascular system [33]. Among them, anti-inflammatory and anti-stress effects may be related to reducing delirium. Two studies on hip fracture surgery and gastrointestinal surgery have shown that esketamine may reduce delirium by lowering levels of interleukin-6 (IL-6), IL-8, IL-10, and tumor necrosis factor (TNF), and reducing neuroinflammatory responses in surgical patients [21, 26]. In addition, two studies by Chen, Wu and colleagues on esketamine in older thoracic surgery and older thoracolumbar fracture surgery found that esketamine can inhibit the activation of the hypothalamic–pituitary–adrenal cortex system, reduce the body's stress response, and reduce the risk of delirium [14, 27].

With regard to secondary outcomes, our results suggested that esketamine can maintain hemodynamic stability after induction, such as reducing the incidence of postinduction hypotension and increasing the mean arterial pressure(MAP) after induction, attributable to the fact that it can stimulate the sympathetic nervous system, resulting in increased heart rate and blood pressure [34]. A recent randomized clinical trial of hysteroscopic surgery also found that esketamine reduced intraoperative hemodynamic fluctuations and the use of vasoactive medications [35]. Besides, esketamine reduced postoperative VAS scores 24 h after surgery to alleviate postoperative pain, which is consistent with the conclusions of a previous meta-analysis of the effect of esketamine on postoperative abdominal pain in adults [36]. Finally, compared with the control group, esketamine did not increase the incidence of postoperative adverse reactions (nausea, vomiting, dizziness, respiratory depression). Similarly, the results of Tu et al. 's study showed that esketamine combined with propofol for anesthesia induction in older patients did not increase the incidence of adverse reactions such as nausea and vomiting, respiratory depression, and delayed recovery [37]. However, a randomized controlled trial of esketamine on postoperative nausea and vomiting in patients undergoing thoracoscopic surgery proved that perioperative infusion of esketamine reduced the incidence of postoperative nausea and vomiting [38]. The difference in results may be due to the timing and dose of esketamine administration, so more studies of esketamine on adverse effects are needed in the future.

This study also conducted subgroup analyses based on older patients, and the results revealed that the application of esketamine reduced the incidence of delirium in older patients. Therefore, esketamine may be potentially beneficial in preventing postoperative delirium in older patients, but more high-quality studies are needed in the future.

The present meta-analysis had several limitations and shortcomings. Firstly, it should be emphasized that there was considerable heterogeneity in the timing and dosage of esketamine in the studies included in the analysis. Secondly, medications in the control group and methods of assessment for POD were not identical, and there may be heterogeneity between some studies. Thirdly, the included studies had small sample sizes and were all conducted in China. Therefore, more large-sample, high-quality randomized controlled studies exploring different countries and different populations are needed in the future.

Conclusion

According to our meta-analysis, the use of esketamine significantly reduced the incidence of POD in patients undergoing elective general anesthesia without increasing the incidence of adverse reactions.

Data availability

All data generated or analyzed during this study are included in the manuscript.

References

  1. Jin Z, Hu J, Ma D. Postoperative delirium: perioperative assessment, risk reduction, and management. Br J Anaesth. 2020;125(4):492–504.

    Article  PubMed  Google Scholar 

  2. Evered LA, Chan MTV, Han R, et al. Anaesthetic depth and delirium after major surgery: a randomised clinical trial. Br J Anaesth. 2021;127(5):704–12.

    Article  PubMed  PubMed Central  Google Scholar 

  3. Glumac S, Kardum G, Karanovic N. Postoperative cognitive decline after cardiac surgery: a narrative review of current knowledge in 2019. Med Sci Monit. 2019;25:3262–70.

    Article  PubMed  PubMed Central  Google Scholar 

  4. Yan E, Veitch M, Saripella A, et al. Association between postoperative delirium and adverse outcomes in older surgical patients: a systematic review and meta-analysis. J Clin Anesth. 2023;90: 111221.

    Article  PubMed  Google Scholar 

  5. Deiner S, Silverstein JH. Postoperative delirium and cognitive dysfunction. Br J Anaesth. 2009;103 Suppl 1(Suppl 1):i41-46.

    Article  CAS  PubMed  Google Scholar 

  6. Mevorach L, Forookhi A, Farcomeni A, et al. Perioperative risk factors associated with increased incidence of postoperative delirium: systematic review, meta-analysis, and grading of recommendations assessment, development, and evaluation system report of clinical literature. Br J Anaesth. 2023;130(2):e254–62.

    Article  PubMed  Google Scholar 

  7. Hovaguimian F, Tschopp C, Beck-Schimmer B, et al. Intraoperative ketamine administration to prevent delirium or postoperative cognitive dysfunction: a systematic review and meta-analysis. Acta Anaesthesiol Scand. 2018;62(9):1182–93.

    Article  CAS  PubMed  Google Scholar 

  8. Viderman D, Aubakirova M, Nabidollayeva F, et al. Effect of ketamine on postoperative neurocognitive disorders: a systematic review and meta-analysis. J Clin Med. 2023;12(13):4314.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Fellous S, Dubost B, Cambriel A, et al. Perioperative ketamine administration to prevent delirium and neurocognitive disorders after surgery: a systematic review and meta-analysis. Int J Surg. 2023;109(11):3555–65.

    PubMed  PubMed Central  Google Scholar 

  10. Hashimoto K. Molecular mechanisms of the rapid-acting and long-lasting antidepressant actions of (r)-ketamine. Biochem Pharmacol. 2020;177:113935.

    Article  CAS  PubMed  Google Scholar 

  11. Qiu D, Wang XM, Yang JJ, et al. Effect of intraoperative esketamine infusion on postoperative sleep disturbance after gynecological laparoscopy: a randomized clinical trial. JAMA Netw Open. 2022;5(12):e2244514.

    Article  PubMed  PubMed Central  Google Scholar 

  12. Cao B, He L, Zhao YY, et al. Effects of low-dose esketamine on hemodynamics during anesthesia induction and postoperative delirium in elderly patients undergoing gastrointestinal surgery. Chinese J Lab Diagn. 2022;26(9):1291–4.

    Google Scholar 

  13. Chen J, Huang J, Xie HC, et al. Examination of the analgesic efficacy of esketamine on postoperative lumbar disc herniation and its influence on the Renin-Angiotensin-Aldosterone System (RAAS). J Cervicodynio Lumbodynia. 2023;44(4):625–8.

    Google Scholar 

  14. Chen M, Lin WW, Fang W. Effect of esketamine combined with double lumen bronchial cannula on elderly patients during thoracic surgery induction. Med Theory Pract. 2023;36(9):1517–9.

    CAS  Google Scholar 

  15. Ding Q, Xie CL, Yue SY, et al. Effect of perioperative intravenous infusion of esketamine or lidocaine on the postoperative early recovery quality of in patients undergoing endoscopic sinus surgery. Pract Pharm Clin Remedies. 2023;26(11):1017–21.

    CAS  Google Scholar 

  16. Cheng LX, Ma GF, Xia XQ. Effect of Subanesthetic Dose of Esketamine Combined with TAPB on Neurocognitive Function in Elderly Patients Undergoing Abdominal Surgery. J Med Inform. 2024;37(4):83–9.

    Google Scholar 

  17. Huang XD. Clinical efficacy of esketamine in anesthesia induction and postoperative analgesia of thoracoscopic radical surgery for lung cancer. North Pharm. 2024;21(1):123–5.

    Google Scholar 

  18. Li Y, Zhu JJ, Liu HY, et al. The Effect of Sub-anaesthetic Dose of Esketamine on the Mood of Breast Cancer Patients after Surgery. Syst Med. 2021;6(23):5–8.

    CAS  Google Scholar 

  19. Li J, Wang Z, Wang A, et al. Clinical effects of low-dose esketamine for anaesthesia induction in the elderly: a randomized controlled trial. J Clin Pharm Ther. 2022;47(6):759–66.

    Article  CAS  PubMed  Google Scholar 

  20. Li YR, Shi XH. Analysis of the Effects of Low-dose Esketamine on Hemodynamics During Induction of Anesthesia and Postoperative Delirium in Elderly Patients Undergoing Gastrointestinal Surgery. China Foreign Med Treat. 2023;42(23):80–3.

    Google Scholar 

  21. Liu J, Wang T, Song J, et al. Effect of esketamine on postoperative analgesia and postoperative delirium in elderly patients undergoing gastrointestinal surgery. BMC Anesthesiol. 2024;24(1):46.

    Article  PubMed  PubMed Central  Google Scholar 

  22. Lu Y, Yin G, Jin C, et al. The application value of esketamine and dexmedetomidine in preventing postoperative delirium and hyperalgesia in elderly patients with thoracic anesthesia. Altern Ther Health Med. 2024;30(3):80–5.

  23. Ma J, Wang F, Wang J, et al. The effect of low-dose esketamine on postoperative neurocognitive dysfunction in elderly patients undergoing general anesthesia for gastrointestinal tumors: a randomized controlled trial. Drug Des Dev Ther. 2023;17:1945–57.

    Article  CAS  Google Scholar 

  24. Xiong X, Shao Y, Chen D, et al. Effect of esketamine on postoperative delirium in patients undergoing cardiac valve replacement with cardiopulmonary bypass: a randomized controlled trial. Anesth Analg. 2024;139(4):743–53.

  25. Sun YB, Wang WX, An HY, et al. Effect of Esketamine on Hemodynamics and Incidence of Postoperative Delirium in Patients Undergoing Coronary Artery Bypass Grafting. HeBei Medicine. 2022;28(4):684–9.

    CAS  Google Scholar 

  26. Ren H, Zhou GW, Fu LL, et al. Effect of low-dose esketamine on postoperative delirium in elderly patients undergoing hip arthroplasty. Acad J Chin PLA Med Sch. 2023;44(8):857–61.

    Google Scholar 

  27. Wu KY, Huang Y, Xu CH, et al. Influence of esketamineused in elderly thoracolumbar fracture surgery on intraoperative hemodynamics and postoperative delirium in patients. J Cervicodynia Lumbodynia. 2023;44(3):361–5.

    Google Scholar 

  28. Xu YZ, Chen Y, Pang HL, et al. The effect of sub-anesthesia doses esketamine on breast cancer patients after surgery. J Int Psychiatry. 2023;50(2):322–4.

    Google Scholar 

  29. Zywiel MG, Hurley RT, Perruccio AV, HancockHoward RL, Coyte PC, Rampersaud YR. Health economic implications of perioperative delirium in older patients after surgery for a fragility hip fracture. J Bone Joint Surg Am. 2015;97:829e36.

    Article  Google Scholar 

  30. Watne LO, Idland AV, Fekkes D, et al. Increased CSF levels of aromatic amino acids in hip fracture patients with delirium suggests higher monoaminergic activity. BMC Geriatr. 2016;16(149):44.

    Google Scholar 

  31. Inouye SK, Bogardus ST, Charpentier PA, et al. A multicomponent intervention to prevent delirium in hospitalized older patients. N Engl J Med. 1999;340(9):669–76.

    Article  CAS  PubMed  Google Scholar 

  32. Peltoniemi MA, Hagelberg NM, Olkkola KT, et al. Ketamine: a review of clinical pharmacokinetics and pharmacodynamics in anesthesia and pain therapy. Clin Pharmacokinet. 2016;55(9):1059–77.

    Article  CAS  PubMed  Google Scholar 

  33. Trimmel H, Helbok R, Staudinger T, et al. S(+)-ketamine : current trends in emergency and intensive care medicine. Wien Klin Wochenschr. 2018;130(9–10):356–66.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Zanos P, Moaddel R, Morris PJ, et al. Ketamine and ketamine metabolite pharmacology: insights into therapeutic mechanisms. Pharmacol Rev. 2018;70(3):621–60.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Guan Y, Pan H, Cong X, et al. Effect of esketamine on haemodynamic fluctuations in patients undergoing hysteroscopic surgery: a prospective, double-blind randomized clinical trial. Br J Clin Pharmacol. 2024;90(11):2754–62.

    Article  CAS  PubMed  Google Scholar 

  36. Xie M, Liang Y, Deng Y, et al. Effect of s-ketamine on postoperative pain in adults post-abdominal surgery: a systematic review and meta-analysis. Pain Physician. 2023;26(4):327–35.

    Article  PubMed  Google Scholar 

  37. Tu W, Yuan H, Zhang S, et al. Influence of anesthetic induction of propofol combined with esketamine on perioperative stress and inflammatory responses and postoperative cognition of elderly surgical patients. Am J Transl Res. 2021;13(3):1701–9.

    PubMed  PubMed Central  Google Scholar 

  38. Qi Y, Zhou M, Zheng W, et al. Effect of s-ketamine on postoperative nausea and vomiting in patients undergoing video-assisted thoracic surgery: a randomized controlled trial. Drug Des Dev Ther. 2024;18:1189–98.

    Article  Google Scholar 

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Authors and Affiliations

  1. Department of Anesthesiology, Central Hospital of Dalian University of Technology, No. 826 Southwest Road, Shahekou District, Dalian, Liaoning Province, China

    Wenhui Zhang, Di Wang, Siru Li, Yutao Chen & Congjie Bi

  2. China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, Liaoning Province, China

    Wenhui Zhang

  3. Dalian Medical University, No. 9 West Section Lvshun South Road, Dalian, Liaoning Province, China

    Di Wang, Siru Li & Yutao Chen

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Wenhui Zhang, Congjie Bi and Di Wang participated in the design, collection of data, statistical analysis and completion of the manuscript. Yutao Chen and Siru Li assisted in data collection and statistical analysis. All the authors have read and approved the final draft.

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Zhang, W., Wang, D., Li, S. et al. Effect of esketamine on postoperative delirium in general anesthesia patients undergoing elective surgery: a meta-analysis of randomized controlled trials. BMC Anesthesiol 24, 442 (2024). https://doiorg.publicaciones.saludcastillayleon.es/10.1186/s12871-024-02833-x

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BMC Anesthesiology

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