Transcutaneous Cranial Electrical Stimulation (Limoge’s Currents) Decreases Early Buprenorphine Analgesic Requirements After Abdominal Surgery

Transcutaneous cranial electrical stimulation with Limoge's currents (TCES) consists of high frequency, low intensity currents which decreased anesthetic requirements during elective surgery. This action is likely to be mediated by the release of central endogenous opioids. In the present study, we hypothesized that TCES applied intraoperatively may decrease early postoperative narcotic requirements. Thirty-nine ASA physical status I and II patients undergoing elective abdominal surgery were enrolled in this prospective, randomized, double-blind, placebo-controlled study. Just before induction of anesthesia, patients were connected to the electrical stimulator and randomly allocated to be either stimulated (TCES group, n = 20) or not (control group, n = 19) during surgery. The managing anesthesiologist was unaware of which group the patient was assigned. Postoperatively, patients were given a patient-controlled analgesia (PCA) device delivering buprenorphine for the first four postoperative hours. The recorded variables included postoperative buprenorphine requirements, pain scores (0-10 visual analog scale [VAS]), sedation (0-4 scale), and intraoperative isoflurane requirements. Patients were comparable with respect to age, sex ratio, weight, duration of surgery, intraoperative hemodynamics, fentanyl requirements, and time from skin closure to tracheal extubation. Buprenorphine requirements were significantly reduced in the TCES group versus the control group (2.36 vs 3.43 micrograms.kg-1.h-1; P = 0.002). Intraoperative isoflurane anesthetic requirements, as well as hourly postoperative scores for pain and sedation, were the same for the two groups. These data indicate that TCES reduces narcotic requirements for early postoperative analgesia. This technique might have potential to facilitate early postoperative analgesia in patients undergoing elective abdominal surgery.