Objective  To systematically review the effect of dexmedetomidine on the cognitive function of elderly patients after general anesthesia for colorectal cancer surgery.

Methods  PubMed, Web of Science, Embase, Cochrane Library, CNKI, WanFang Data, VIP, and SinoMed databases were electronically searched to collect randomized controlled trials (RCTs) on the effect of dexmedetomidine on the cognitive function of elderly patients after general anesthesia for colorectal cancer surgery from inception to June 30, 2025. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of included studies. The Meta-analysis was performed by using RevMan 5.3 software.

Results  A total of 13 RCTs involving 1,324 patients were included. The Meta-analysis showed that compared with 0.9% sodium chloride injection or blank control, dexmedetomidine can reduce the incidence of postoperative cognitive dysfunction [OR=0.21, 95%CI (0.16, 0.28), P<0.001], interleukin-6 levels on postoperative 1 d [MD=-18.19, 95%CI (-26.73, -9.64), P<0.001], tumor necrosis factor-α level on postoperative 1 d [MD=-16.68, 95%CI (-31.57, -1.79), P=0.03], and increase postoperative outcomes 1 d [MD=4.14, 95%CI (3.27, 5.01), P<0.001], 3 d [MD=3.80, 95%CI (2.91, 4.69), P<0.001] score of the Mini-Mental State Examination (MMSE). The incidence of adverse reactions in the dexmedetomidine group was significantly lower than that in the control group [OR=0.34, 95%CI (0.12, 0.95), P=0.04].

Conclusions  Current evidence shows that the intraoperative use of dexmedetomidine in elderly patients undergoing general anesthesia for colorectal cancer surgery can reduce the incidence of postoperative cognitive impairment in patients and has a neuroprotective effect on the nervous system, which may improve their postoperative cognitive impairment. Due to the limited quality and quantity of the included studies, more further large-scale multicenter studies are required to verify the above conclusion.

1.Bray F, Laversanne M, Sung H, et al. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries[J]. CA Cancer J Clin, 2024, 74(3): 229-263. DOI: 10.3322/caac.21834.

2.国家卫生健康委员会医政司, 中华医学会肿瘤学分会. 中国结直肠癌诊疗规范（2023版）[J]. 协和医学杂志, 2023, 14(4): 706-733. DOI: 10.12290/xhyxzz.2023-0315.

3.刘丽佳, 路建, 周红梅. 右美托咪定在老年患者术后认知功能障碍中的研究进展[J]. 中国现代医生, 2023, 61(36): 117-120. DOI: 10.3969/j.issn.1673-9701.2023.36.026.

4.代晨旭, 张野. 右美托咪定应用于老年结直肠癌根治术中对麻醉苏醒期及神经认知功能的保护作用[J]. 中国老年学杂志, 2021, 41(10): 2093-2096. DOI: 10.3969/j.issn.1005-9202.2021. 10.024.

5.韦智经. 老年结肠癌腹腔镜切除术后发生认知功能障碍的危险因素[J]. 吉林医学, 2025, 46(2): 340-343. DOI: 10.3969/j.issn.1004-0412.2025.02.023.

6.鲍瑞, 毛慧娟, 宋花玲, 等. 社会活动参与对我国老年人认知功能的影响——基于中国健康与养老追踪调查数据 [J]. 数理医药学杂志, 2024, 37(1): 41-51. [Bao R, Mao HJ, Song HL, et al. The impact of social activity participation on cognitive function among Chinese elderly: based on data from China Health and Retirement Longitudinal Study[J]. Journal of Mathematical Medicine, 2024, 37(1): 41-51.] DOI: 10.12173/j.issn.1004-4337.202311040.

7.温弼堂, 曾宇熙, 温健良. 右美托咪定预防经尿道前列腺电切术后老年患者认知障碍的临床效果[J]. 智慧健康, 2024, 10(25): 83-85. [Wen BT, Zeng YX, Wen JL. Clinical effect of dexmedetomidine in preventing cognitive impairment of elderly patients after transurethral resection of prostate[J]. Smart Healthcare, 2024, 10(25): 83-85.] DOI: 10.19335/j.cnki.2096-1219.2024.25.025.

8.吴华彬, 何玉花, 夏向锋, 等. 右美托咪定对老年结直肠肿瘤患者腹腔镜手术后脑功能的影响[J]. 中国初级卫生保健, 2023, 37(9): 90-93, 99. [Wu HB, He YH, Xia XF, et al. Effect of dexmedetomidine on brain function after laparoscopic surgery for colorectal neoplasms in elderly patients[J]. Chinese Primary Health Care, 2023, 37(9): 90-93, 99.] DOI: 10.3969/j.issn.1001-568X.2023.09.0025.

9.徐志燕, 陈伟元, 姚伟锋. 右美托咪定改善衰弱老年围术期神经认知障碍的机制及研究进展[J]. 实用医学杂志, 2024, 40(17): 2503-2507. [Xu ZY, Chen WY, Yao WF. Mechanism and research progress of dexmedetomidine in improving perioperative neurocognitive disorder in frail elderly patients[J]. The Journal of Practical Medicine, 2024, 40(17): 2503-2507.] DOI: 10.3969/j.issn.1006-5725.2024.17.025.

10.Higgins JP, Altman DG, Gøtzsche PC, et al. The Cochrane Collaboration's tool for assessing risk of bias in randomised trials[J]. BMJ, 2011, 343: d5928. DOI: 10.1136/bmj.d5928.

11.陈小刚, 汪正伟. 右美托咪定对老年结直肠癌患者术后认知功能及血浆miR-206、BDNF水平的影响[J]. 东南大学学报（医学版）, 2021, 40(4): 442-449. [Chen XG, Wang ZW. Effects of dexmedetomidine on postoperative cognitive function and plasma miR-206 and BDNF levels in elderly patients with colorectal cancer[J]. Journal of Southeast University (Medical Science Edition), 2021, 40(4): 442-449.] DOI: 10.3969/j.issn.1671-6264.2021.04.004.

12.陈洋, 梁永圣, 唐波. 右美托咪定对老年结肠癌患者全麻术后认知功能障碍的影响临床研究[J]. 中国当代医药, 2021, 28(34): 135-138. [Chen Y, Liang YS, Tang B. Clinical study on the effect of dexmedetomidine on cognitive dysfunction after general anesthesia in elderly patients with colon cancer[J]. China Modern Medicine, 2021, 28(34): 135-138.] DOI: 10.3969/j.issn.1674-4721.2021.34.037.

13.曲竞, 汪涛, 刘冰, 等. 右美托咪定对老年结肠癌手术后认知功能障碍的影响[J]. 大连医科大学学报, 2020, 42(4): 309-312. [Qu J, Wang T, Liu B, et al. Effect of dexmedetomidine on postoperative cognitive dysfunction in elderly patients with colorectal cancer[J]. Journal of Dalian Medical University, 2020, 42(4): 309-312.] DOI: 10.11724/jdmu.2020.04.05.

14.Chen H, Li F. Effect of dexmedetomidine with different anesthetic dosage on neurocognitive function in elderly patients after operation based on neural network model[J]. World Neurosurg, 2020, 138: 688-695. DOI: 10.1016/j.wneu.2020.01.012.

15.刘辉, 李丽丽, 韩景田, 等. 右美托咪定对直肠癌患者术后认知功能障碍的影响[J]. 中国临床医生杂志, 2017, 45(8): 83-85. DOI: 10.3969/j.issn.2095-8552.2017.08.029.

16.刘涛, 张建峰, 李明强. 右美托咪定对老年腹腔镜结直肠癌根治术病人围术期血浆皮质醇的影响[J]. 实用老年医学, 2017, 31(4): 386-388. DOI: 10.3969/j.issn.1003-9198.2017.04.025.

17.周霞. 右美托咪定对结直肠癌手术后早期认知功能障碍的影响[J]. 河南医学研究, 2017, 26(3): 452-453. DOI: 10.3969/j.issn.1004-437X.2017.03.032.

18.郭超. 右美托咪定对结直肠癌手术后早期认知功能障碍的影响[J]. 河南医学研究, 2017, 26(16): 2999-3000. DOI: 10.3969/j.issn.1004-437X.2017.16.071.

19.林柳蓉, 吴冰冰, 林兰英. 右美托咪定对结直肠癌腹腔镜手术老年患者术后认知功能障碍及血清神经元烯醇化酶、S100β蛋白、肿瘤坏死因子-α水平的影响[J]. 中国老年学杂志, 2017, 37(6): 1463-1465. DOI: 10.3969/j.issn.1005-9202. 2017.06.070.

20.曹福羊, 马丽, 李娟, 等. 右美托咪定辅助全身麻醉对老年结直肠癌患者术后早期认知功能的影响[J]. 山东医药, 2015(40): 76-78. DOI: 10.3969/j.issn.1002-266X.2015.40.030.

21.彭毅梅, 赵倩. 右美托咪定对于结直肠癌手术后早期认知功能障碍影响观察[J]. 中国煤炭工业医学杂志, 2015(1): 30-32. [Peng YM, Zhao Q. Effects of dexmedetomidine on postoperative early cognitive dysffunction after colorectal cancer surgery[J]. Chinese Journal of Coal Industry Medicine, 2015(1): 30-32.] DOI: 10.11723/mtgyyx1007-9564201501010.

22.陆燕艳, 蒋培余, 江山秀. 老年病人术后认知障碍的影响因素及其干预措施研究进展[J]. 循证护理, 2022, 8(19): 2609-2612. [Lu YY, Jiang PY, Jiang SX. Research progress on influencing factors and intervention measures of postoperative cognitive dysfunction in elderly patients[J]. Chinese Evidence-Based Nursing, 2022, 8(19): 2609-2612.] DOI: 10.12102/j.issn.2095-8668.2022.19.011.

23.樊志龙, 汪海涛, 顾静. 右美托咪定辅助麻醉对全髋关节置换术患者脑氧代谢、应激反应的影响分析[J]. 中外医疗, 2024, 43(28): 59-62, 71. [Fan ZL, Wang HT, Gu J. Effects of dexmedetomidine assisted anesthesia on cerebral oxygen metabolism and stress response in patients undergoing total hip arthro-plasty[J]. China & Foreign Medical Treatment, 2024, 43(28): 59-62, 71.] DOI: 10.16662/j.cnki.1674-0742.2024.28.059.

24.叶映芬, 李昆伦, 陈伟元, 等. 右美托咪定在骨科手术麻醉与镇痛中的应用进展[J]. 药学前沿, 2024, 28(12): 711-718. [Ye YF, Li KL, Chen WY, et al. Application progress of dexmedetomidine in anesthesia and analgesia during orthopedic surgery[J]. Frontiers in Pharmaceutical Sciences, 2024, 28(12): 711-718.] DOI: 10.12173/j.issn.2097-4922.202406108.

25.van Hoorn CE, Hoeks SE, Essink H, et al. A systematic review and narrative synthesis on the histological and neurobehavioral long-term effects of dexmedetomidine[J]. Paediatr Anaesth, 2019, 29(2): 125-136. DOI: 10.1111/pan.13553.

26.Lei D, Sha Y, Wen S, et al. Dexmedetomidine may reduce IL-6 level and the risk of postoperative cognitive dysfunction in patients after surgery: a Meta-analysis[J]. Dose Response, 2020, 18(1): 1559325820902345. DOI: 10.1177/1559325820902345.

27.Wang T, Huang X, Sun S, et al. Recent advances in the mechanisms of postoperative neurocognitive dysfunction: a narrative review[J]. Biomedicines, 2025, 13(1): 115. DOI: 10.3390/biomedicines13010115.

28.尹璇, 黄睿健, 孔斯予, 等. 围手术期药物相关罕见不良反应发现的真实世界数据基础与方法学进展[J]. 药物流行病学杂志, 2025, 34(8): 917-925. [Yin X, Huang RJ, Kong SY, et al. Perioperative rare adverse reactions discovery: real-world data foundations and methodological advances[J]. Chinese Journal of Pharmacoepidemiology, 2025, 34(8): 917-925.] DOI: 10.12173/j.issn.1005-0698.202411007.