[Effects of transcutaneous electrical acupoint stimulation at different times assisted general anesthesia on stress response of patients undergoing open posterior lumbar surgery].

Objective: To observe the effects of transcutaneous electrical acupoint stimulation (TEAS) at different times on the stress response during anesthesia and operation in the patients undergoing open posterior lumbar surgery.

Methods: A total of 94 patients undergoing open posterior lumbar surgery were randomly assigned to preoperative TEAS group(32 cases), intraoperative TEAS group(31 cases) and sham-TEAS group(31 cases). The same anesthetic method was used in the patients of 3 groups. Four electrodes were attached to the bilateral Hegu (LI4) and Neiguan (PC6) and connected to the electronic acupuncture instrument when patients entered the operation room. In the preoperative TEAS group, the patients received TEAS (10 to 20 mA) for 30 min before the anesthetic induction. TEAS (15 mA) was provided immediately when the operation starts till the end of ope-ration for the patients of the intraoperative TEAS group. In the sham-TEAS group, the electronic acupuncture instrument was switched on during the whole procedure of operation, but no electric current was output. Separately, at the moment of entering the operation room (T₀), before endotracheal intubation (T₁), at the time of endotracheal intubation (T₂), 10 min after skin resection (T₃), at the end of surgery (T₄), recovery from anesthesia (T₅) and at the time of extubation (T₆), the heart rate (HR) and mean arterial pressure (MAP) were recorded. Using ELISA, the concentrations of epinephrine (E), norepinephrine (NE), dopamine (DA), cortisol (Cor) in serum were assayed at T₀, T₃, and T₄; and blood glucose was tested with blood sugar paper at the same time points.

Results: Compared with T₀ of the same group, HR was increased at T₂ and decreased at T₃ of the patients in the sham-TEAS group and the intraoperative TEAS group (P<0.05). Compared with the sham-TEAS group at the same time points, HR was decreased at T₂ and increased at T₃ of the patients in the preoperative TEAS group (P<0.05), and it was decreased at T₆ of patients in the intraoperation TEAS group (P<0.05). HR was reduced at T₂ in the preoperative TEAS group when compared with the intraoperative TEAS group. Compared with T₀ of the same group, MAP was elevated at T₂ and reduced at T₃ and T₄ in the sham-TEAS group (P<0.05); it decreased at T₃, T₄ and T₅ in the preoperative TEAS group (P<0.05); it rose at T₂ and was reduced at T₃, T₄ and T₅ in the intraoperative TEAS group (P<0.05). When compared with the sham-TEAS group at the same time points, MAP decreased at T₂ in the preoperative TEAS group (P<0.05), and at T₆ in the intraoperative TEAS group (P<0.05). MAP was reduced at T₂ and elevated at T₆ in the preoperative TEAS group in comparison with the intraoperative TEAS group (P<0.05) at the same time points. Compared with T₀ of the same group, the contents of E was increased at T₃ in the sham-TEAS group and the intraoperative TEAS group (P<0.05); it was increased in all of the three groups at T₄ (P<0.05); the contents of NE, DA, Cor and the blood glucose were increased at T₄ in the sham-TEAS group (P<0.05). Compared with the sham-TEAS group at the same time points, the contents of E, DA at T₃ and T₄ and Cor at T₃ in serum of the preoperative TEAS group were decreased (P<0.05); and the contents of E, NE, DA and Cor at T4 in the intraoperative TEAS group were decreased (P<0.05).

Conclusion: TEAS-assisted general anesthesia can better maintain the stability of HR and MAP during anesthesia and operation in patients undergoing open posterior lumbar surgery, and reduce surgical stress response.