Effects of transcutaneous electrical acupoint stimulation on perioperative immune function and postoperative analgesia in patients undergoing radical mastectomy: A randomized controlled trial

Radical mastectomy may lead to suppression of cellular immune function in patients with malignant tumors. Transcutaneous electrical acupoint stimulation (TEAS) is widely used in clinical practice. However, there have been relatively few studies on the effects of TEAS on postoperative analgesia and immune function. The present study aimed to evaluate the effects of TAES on postoperative pain and immune function in patients undergoing radical mastectomy. A total of 65 patients were enrolled and allocated to either receive TEAS or sham TEAS. TEAS was implemented on bilateral Hegu (LI4), Neiguan (PC6) and Zusanli (ST36) acupoints simultaneously for 30 min before induction of anesthesia at 4 and 12 h post-operation. The primary outcomes included visual analogue scale (VAS) scores at 4 h (T(1)), 12 h T(2)), 24 h (T(3)) and 48 h (T(4)) post-operation, and serum levels of IL-2, IL-4, IFN-γ and the IL-2/IL-4 ratio at 30 min before TEAS (T(0)), T(1), T(2), T(3) and T(4). Secondary outcomes included the cumulative time of rescue analgesia within 48 h post-surgery, as well as the incidence of postoperative nausea and vomiting (PONV) and pruritus. Compared with the sham TEAS group, postoperative VAS scores at T(2) and T(3), the total consumption of opioids in the patient-controlled analgesia (PCA) pump, pressing times of the PCA pump and the incidences of PONV and headache were significantly lower in the TEAS group. The serum levels of IFN-γ at T(3) and T(4), and the serum levels of IL-2 and the IL-2/IL-4 ratio at T(2), T(3) and T(4) were higher in the TEAS group compared with the sham TEAS group. By contrast, the serum levels of IL-4 were lower at T(2), T(3) and T(4) in the TEAS group compared with the sham TEAS group. The results indicated that TEAS could improve postoperative analgesia, reduce postoperative consumption of opioids and alleviate postoperative side effects. Simultaneously, TEAS was able to reverse decreased serum levels of IL-2 and IFN-γ, reduce the level of IL-4 and restore the balance of Th1/Th2, thereby partially attenuating perioperative immune function depression in patients with breast cancer. The current trial was registered prior to participant enrollment at www.chictr.org.cn (Clinical Trial no. ChiCTR1800017768).