| BackgroundPostoperative delirium is an acute cerebral dysfunction syndrome.The incidence of postoperative delirium varies among different patient populations,ranging from 15%to 54%in patients undergoing major abdominal surgery,and up to 50%in elderly patients undergoing high-risk surgery.Postoperative delirium is associated with poor prognosis,including increased risk of postoperative cognitive dysfunction and dementia,increased medical resources consumption as well as increased incidence of complications and mortality.The pathogenesis of postoperative delirium is not well understood.Development of delirium is the consequence of the complex interactions of many factors.Patients factors include older age,with severe comorbidities and cognitive impairment.Precipitating factors include use of benzodiazepines,emergent surgery,hypotension,pain,and sleep disturbance.Inflammation,oxidative stress,changes in neurotransmitters,endocrine disorders and sleep disorders may be involved in the development of delirium.Therefore,reducing the precipitating factors of delirium,and alleviating inflammation and brain injury may be effective in preventing delirium.Previous studies have demonstrated the beneficial effects of acupuncture in reducing intraoperative opioid dosage and postoperative pain,maintaining intraoperative hemodynamic stability,attenuating inflammatory response,alleviating cerebral ischemia/reperfusion injury,and improving postoperative sleep quality.In addition,a few preliminary clinical studies have proved that acupuncture may reduce the incidence of delirium.However,more clinical studies are needed to further evaluate and verify the role of acupuncture in prevention of postoperative delirium,and to further explore the possible mechanisms.Transcutaneous electrical acupoint stimulation（TEAS）and auricular acupressure are alternatives of acupuncture therapy with the advantages of non-invasive,easy-to-operate,and thus more acceptable to patient.In clinical practice,body acupuncture and auricular acupuncture are commonly combined to produce add-on effects.Previous studies also showed that compared with auricular acupuncture alone,auricular combined with body acupuncture therapy may provide a better effect on improving patients’sleep quality and alleviating postoperative pain.At present,there is no study investigating the effect of TEAS combined with auricular acupressure on postoperative delirium in elderly patients.By applying TEAS combined with auricular acupressure as an intervention,this study aimed to investigate its efficacy on preventing postoperative delirium.ObjectiveThis study aimed to evaluate the effects of TEAS combined with auricular acupressure on postoperative delirium in elderly patients undergone abdominal surgery,and to further explore whether TEAS prevented postoperative delirium by reducing inflammation and brain injury.MethodsA total of 210 elderly patients scheduled for elective abdominal surgery was enrolled and randomized in a 1:1 ratio to intervention group and control group.TEAS was performed on bilateral Hegu,Neiguan and Zusanli acupoints 30 minutes before anesthesia induction and maintained to the end of the operation.TEAS was performed with a disperse-dense frequency of 2/10 Hz,and with current intensity of 5-10 m A for the upper limbs and 10-20m A for the lower limbs.The final stimulus current was defined as the intensity at which the patient could tolerate the sensation of De Qi.Intermittent unilateral auricular acupressure（through Shenmen,Zero point,Heart,Liver,Subcortical,Sympathic and Endocrine）was applied for 3 min each time,5 times a day during the first 3 postoperative days.The control group received standard care without acupuncture intervention.The blood samples were collected in the intervention group before TEAS（in the control group before anesthesia）and immediately after surgery.The serum levels of interleukin-6,interleukin-10,nerve growth factor,tumor necrosis factor-α,S100β,matrix metalloproteinase-9,aquaporin-4,Tau protein andβ-amyloid 1-42 were measured using Enzyme linked immunosorbent assay.The primary outcome was the cumulative incidence of delirium in the first 7 postoperative days or during hospitalisation if patients were discharged within 7 days after surgery using Confusion assessment method or Confusion assessment method for the Intensive Care Unit.Secondary outcomes included the severity of delirium using memorial delirium assessment scale（MDAS）,perioperative opioid consumption,postoperative pain within postoperative3 days,sleep quality score on postoperative day 4 using Pittsburgh sleep quality index（PSQI）,length of hospitalization,non-delirium adverse events within postoperative 30 days,and levels of serum indexes before and after surgery.Analyses of outcomes were performed on intention-to-treat population.The cumulative postoperative delirium incidence was calculated with the Kaplan-Meier estimator.Changes in the Memorial Delirium Assessment Scale within 7 postoperative days were compared using a generalized linear mixed-effect model.Post-hoc subgroup analyses were performed using a Cox proportional hazards model to investigate the intervention effects on the cumulative delirium incidence in specific subgroups.Sensitivity analyses were done in the per-protocol population.ResultsIn this single-center,prospective,randomized,assessor-blinded clinical study,data of 210patients were included in the intentional-treatment analysis,with 105 patients in each group.Postoperative delirium occurred in 8 of 105 patients（7.6%）in the intervention group and in19 of 105 patients（18.1%）in the control group（relative risk 0.42,95%CI 0.19 to 0.92,P=0.023）.Kaplan-Meier survival analysis showed that delirium was less likely to occur in the intervention group than in the control group within postoperative 7 days（P=0.023）.Compared with the Control group,patients in the intervention group have a significantly lower MDAS scores（4 vs.3,median difference-1,95%CI-1 to 0,P=0.010）and lower PSQI score（10 vs.8,difference-2,95%CI-3 to-1,P=0.001）.Generalized linear mixed effects model analysis showed that MDAS scores was significant lower on postoperative day 2（P=0.007）,day 3（P<0.001）,and day 4（P=0.037）in the intervention group.There were no significant differences between the two groups regarding the dosages of sufentanil and remifentanil,pain intensity at rest and at movement on postoperative days 1 to 3,length of postoperative hospitalization,and non-delirium complications within postoperative 30days.Cox subgroup analysis showed that patients who underwent upper abdominal surgery were more likely to benefit from the intervention（hazard ratio 0.16,95%CI 0.04-0.71,P=0.005）.Postoperative serum level of IL-6（58.3 vs.37.2,P=0.032）,S100β（114.8 vs.73.2,P=0.024）and MMP-9（231.2 vs.172.0,P=0.015）were significantly lower in the intervention group.The serum levels of IL-10,TNF-α,NGF,AQP-4,Tau protein and Aβ1-42were comparable between the two groups.ConclusionsTranscutaneous electric acupoint stimulation combined with auricular acupressure could significantly lower the incidence and severity of postoperative delirium and improve sleep quality in elderly patients undergoing abdominal surgery.TEAS could reduce inflammation and brain injury by reducing the serum levels of IL-6,S100βand MMP-9,which may be related to the prevention of acupuncture for postoperative delirium. |
PDF Full Text Request