Analgesic effect of transcutaneous electrical stimulation at the auricularShenmen (H 7) point after total knee arthroplasty / 中国组织工程研究

ABSTRACT

BACKGROUND: Transcutaneous electrical acupoint stimulation (TEAS) exerts good analgesic effect, but its effectiveness and safety in analgesia after total knee arthroplasty have not been reported.OBJECTIVE: To evaluate the analgesic effect of TEAS at the auricular Shenmen (H 7) point in patients undergoing total knee arthroplasty.METHODS: Forty ASA Ⅰ-Ⅲ patients scheduled for total knee arthroplasty under general anesthesia combined with femoral nerve block were enrolled and randomly divided into experimental and control groups (n=20 per group). The patients in the experimental group received TEAS at auricular Shenmen (H 7) point before anesthesia, 8, 16, 36, and 56 hours postoperatively for 30 minutes. The patients in the control group received same method with the experimental group, but without electrical stimulation. Ultrasound-guided continuous femoral nerve blockade was performed before induction, followed by tracheal tube was inserted and the patients were mechanically ventilated. The patients received patient-controlled continuous femoral nerve analgesia after surgery for 72 hours. The Visual Analogue Scale scores and the quadriceps maximum voluntary isometric contraction were recorded at postoperative 6, 12, 24, 48 and 72 hours. The consumption of ropivacaine and tramadol hydrochloride was recorded. Additionally, the incidence of adverse reactions was recorded.RESULTS AND CONCLUSION: (1) The Visual Analogue Scale scores in the experimental group were significantly lower than those in the control group at postoperative 48 and 72 hours (P < 0.05). (2) The quadriceps maximum voluntary isometric contraction in the control group was significantly lower than that in the experimental group at each time point (P < 0.05). (3) The consumption of ropivacaine in the control group ((495.7±39.4) mL) was significantly more than that in the experimental group ((394.5±27.1) mL) (P < 0.05). Seven cases in the control group and one case in the experimental group received the injection of tramadol hydrochloride (P < 0.05). (4) Nausea and vomiting occurred in six cases in the control group and one case in the experimental group, and dizziness only occurred in four cases in the control group (P < 0.05). (5) To conclude, TEAS at the auricular Shenmen (H 7) point can improve the pain after total knee arthroplasty, reduce the consumption of ropivacaine and tramadol hydrochloride, and maintain quadriceps strength.