The aim of the present study is the comparison of the efficacy of the perioperative application of a multimodal analgesia model to the patients, combing common used analgesics via intravenous (IV) route, such as tramadol and ketamine, with or without the Electroacupuncture (E/A) technique application and the frequency of side effects accession.

Seventy patients were scheduled for radical prostatectomy, were recruited to this prospective single-blind, were randomized and placebo-controlled by trial. They were randomly divided into two groups of 35 patients each by a computer-generated randomization sequence, the TKE (Tramadol + Ketamine + Electroacupuncture), and TK (Tramadol + Ketamine + placebo Electroacupuncture.The randomization performed by the certified acupuncturist.

Patients were anesthetized with the same protocol by five anesthesiologists, who were not involved in the postoperative assessment of the patients, but were aware in which group acupuncture was used and in which not. Both groups, TKE and TK, were administered tramadol 1.5mg/kg and ketamine 10mg bolus IV 30min before the end of the surgery and co instantaneously the CIV infusion of tramadol 0.15mg/kg/h and ketamine, in subanesthetic doses, 0.15mg/kg/h started with continuous infusion in an adjustable flow disposable pump (paragon®).Ketamine's dose was altered so as not to exceed the 300mg/24h. An hour before the end of the surgery all patients were administered with parecoxib 40mg (IV) and 30min before paracetamol 20mg/kg (IV).

In TKE group when the closure of the abdominal walls started, a certified acupuncturist expert put needles, Ener-Qi 0.26Χ25mms, in LI4 point at 2cm depth in both hands and E/A was applied for 30min with the E/A stimulator ITO ES-160 in constant pulse program with 300μs duration and 100Hz frequency. After the needles were connected to the E/A stimulator, they were secured by adhesive tape. The response which certified the right needle placement was the adjacent muscular twitch. Thereafter the electroacupuncture machine was deactivated and after the awakening of the patients, E/A was administered in ST36 and LI4 points for 30min with 4Hz frequency. The electrodes were connected to each other in every point, as the right with the left point of LI4 and the right with the left point of ST36. In the TK group the needles were not inserted in the skin but they were put atop the skin and were secured by adhesive tape, the indicator light was on but no electrical current was applied. The patients were told that they may or may not feel electrical current because of its very high frequency.

The study was single blind as patients although they were informed for the Electroacupuncture (E/A) technique during the first session they were anesthetized and the second one was after the awakening of anesthesia and they didn't understand it. On the other hand anaesthesiologists and the certified acupuncturist during the EAc application knew in which group patients belong although they did not deal with them postoperatively. However, patient assessments were performed at standard time points as 45 min in recovery and at 2 h, 6 h, 12 h and 24 h after surgery in the ward by another anaesthesiologist who was not present during the surgery or the recovery room for the first 30 min.

Inclusion Criteria:

• Male patient is over 18 years old, especially 50-75 years old
• Patient scheduled for a non-emergency operation
• Patient signs and dates a written informed consent form (ICF) and indicates an understanding of the study procedures

Exclusion Criteria:

• Patient receiving monoamine oxidase inhibitors and selective serotonin reuptake inhibitors
• Patient with significant cardiovascular, pulmonary, renal or hepatic disease
• Patient with epilepsy non controlled with treatment or history of seizures
• Patient with morbid obesity (BMI>35)
• Patient with history of chronic opioid exposure
• Patient with history of chronic pain
• Patient with history of postoperative nausea and vomiting
• Patient with cognitive dysfunction
• Patient with history of previous usage of the acupuncture technique
• Patient Greek speaking
• Patient is participating in another clinical trial which may affect this study's outcomes
• Patient with metastatic cancer