The effect of electroacupuncture preconditioning on cognitive impairments following knee replacement among elderly: A randomized controlled trial

Abstract

ObjectiveTo investigate if electroacupuncture (EA) preconditioning can mitigate cognitive impairments and reduce the incidence of postoperative cognitive dysfunction (POCD) following knee replacement and its safety among elderly. MethodsTotally 60 participants met the inclusion criteria were enrolled in a randomized controlled trial a ratio of 1:1, with 30 cases allocated to the treatment group and 30 cases allocated to the control group, respectively. The participants in the treatment group were provided with real-EA therapy whereas participants in control group were provided with placebo-EA therapy (Streitberger Placebo-needle). In both groups, Tou sanshen (头三神) acupoints, including Sìshéncōng (四神聪EX-HN1), Shéntíng (神庭 GV24), and bilateral Běnshén (本神GB13) were adopted as the main acupoints, while Bǎihuì (百会GV20), bilateral Hégǔ (合谷LI4), and bilateral Tàichōng (太冲LR3) were adopted as matching acupoints. Interventions were offered 5 days prior to the surgery, once daily, and continued for total 5 days. The global scores of Mini-Mental State Examination (MMSE), and levels of serum inflammatory cytokines including interleukin 1β (IL-1β) and tumor necrosis factor-α (TNF-α), and S100-β protein were observed at 24 h prior to the surgery, and postoperative 24 and 72 h respectively for assessing the incidence of POCD and the severity of cognitive impairments among patients. Meanwhile, adverse effects were monitored and recorded. Results(1) Compared with baseline, MMSE global scores in both treatment and control groups markedly decreased at postoperative 24 h. MMSE global scores in treatment group decreased from 29.43 ± 0.97 to 27.10 ± 1.95 while that in control group decreased from 29.27 ± 1.01 to 26.83 ± 2.25 (all ?P < 0.05), and this trend continued until postoperative 72 h (at postoperative 72 h, MMSE global scores in treatment group was 26.53 ± 2.26 versus 24.79 ± 3.03 in control group). Moreover, decline in control group was more significant than that in treatment group at postoperative 72 h (P < 0.05). (2) Compared with baseline, levels of serum IL-1β, TNF-α and S100-β in both groups increased markedly at postoperative 24 and 72 h. IL-1β in treatment group increased from 43.13 ± 5.51 to 73.13 ± 2.32 at postoperative 24 h and reached 83.17 ± 5.95 at postoperative 72 h, while IL-1β in control group increased from 44.87 ± 5.83 to 91.10 ± 3.55 at postoperative 24 h and reached 111.93 ± 9.18 at postoperative 72 h; TNF-α in treatment group increased from 51.27 ± 6.48 to 88.80 ± 3.55 at postoperative 24 h and reached 94.37 ± 5.22 at postoperative 72 h, while TNF-α in control group increased from 52.07 ± 7.48 to 116.37 ± 3.14 at postoperative 24 h and reached 121.40 ± 3.68 at postoperative 72 h (both ?P < 0.05), furthermore, increases of IL-1β and TNF-α levels in control group were more significant (P < 0.05). Statistical difference in level of S100-β was not observed (P > 0.05). (3) There was no statistical difference in POCD incidence at postoperative 24 h and postoperative 72 h between two groups (P > 0.05), though the incidence of POCD in patients receiving real-EA therapy was indeed much lower than that in patients receiving placebo-EA therapy, particularly at postoperative 72 h (POCD incidence rate at postoperative 24 h in treatment group was 26.67%, 30.00% in control group; POCD incidence rate at postoperative 72 h in treatment group was 30.00%, 46.67% in control group). (4) No serious adverse events were reported in this trial. No one dropped out from this trial. ConclusionEA preconditioning can mitigate cognitive impairments at post-knee replacement surgery 24 and 72 h in elderly through inhibiting expression of inflammation. However, there is insufficient evidence to support that EA pretreatment can reduce the incidence of POCD.