ObjectiveTo systematically review the influence of dexmedetomidine on early postoperative cognitive dysfunction (POCD) and serum inflammatory factors in elderly patients.MethodsWe searched PubMed, EMbase, The Cochrane Library, CBM, CNKI, WanFang Data and VIP databases from inception to April 2017, to collect randomized controlled trials (RCTs) about dexmedetomidine for early POCD in elderly patients. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of included studies. Then, meta-analysis was performed by RevMan 5.3 software.ResultsA total of 23 RCTs, including 2 026 patients were enrolled. The results of meta-analysis showed that, the incidence of POCD in the dexmedetomidine group was lower than that in the control group (the first day: RR=0.40, 95%CI 0.30 to 0.53, P<0.000 01; the third day: RR=0.33, 95%CI 0.23 to 0.48,P<0.000 01; the seventh day: RR=0.42, 95%CI 0.22 to 0.78,P=0.006). Meanwhile, compared with the control group, the dexmedetomidine group significantly decreased the serum levels of TNF-α (immediately after operation: MD=–5.43, 95%CI –7.44 to –3.42, P<0.000 01; 1 h after operation: MD=–4.64, 95%CI –6.92 to –2.36,P<0.000 1; 24 h after operation: MD=–3.27, 95%CI –4.92 to –1.63,P<0.000 1) and IL-6 (immediately after operation: MD=–30.69, 95%CI –41.39 to –20.00,P<0.000 01; 1h after operation: MD=–20.84, 95%CI –28.87 to –12.80,P<0.000 01; 24 h after operation: MD=–13.42, 95%CI –19.90 to –6.94,P<0.000 1).ConclusionCurrent evidence indicates that dexmedetomidine could relief early POCD in elderly patients, in which the reduction of serum inflammatory factors alleviate inflammation response may play a vital role. Due to the limited quality and quantity of included studies, more high quality RCTs are required to verify the above conclusion.