Tu2036 Electroacupuncture analgesia for endoscopic ultrasound: A prospective, randomized, double-blinded, sham-controlled study

OBJETIVE:Electroacupuncture (EA) has been used as part of Traditional Chinese Medicine (TCM) for centuries. However, limited scientific data exist on the benefits and risks of EA as an option of analgesia during endoscopy. The aim of this study is to investigate the efficacy of EA in reducing procedure-related pain and the consumption of analgesics during EUS. METHODS:This was a prospective randomized, double-blinded, sham-controlled study conducted between Dec 2013 to Jan 2013. Consecutive patients who were aged between 18 and 80 years, undergoing EUS for the first-time and were of American Society of Anesthesiologists grading I-II were recruited. They were randomized to receive EA or sham EA. EA was applied to acupoints relevant to the treatment of upper abdominal pain and anxiety, including Zusanli (stomach meridian ST-36), Hegu (large intestine meridian LI-4), and Neiguan (pericardium meridian PC-6). Electric stimulation was employed to the needles at a frequency of 2 Hz, pulse width of 200 $\mu$s, and stimulation intensity short of discomfort. The primary outcome of the study was the dose of patient-controlled analgesia consumed (propofol and alfentanil). The secondary outcomes of the study included overall pain score, patients’ satisfaction, the willingness to repeat the procedure, endoscopists’ satisfaction score, total procedure time, episodes of hypotension, and episodes of desaturation. A scheduled interim analysis was performed was half of the study recruitment was achieved. RESULTS:During the study period, 64 patients were recruited to the study. There were no significant differences between the two groups in background demographics. The number of patients that underwent radial, linear or mini-probe examinations was also similar. Patients in the EA group had significantly lower total dosage of propofol requirement ($P < 0.001$), number of PCA demands ($P < 0.001$), overall pain score ($P < 0.001$) and patient satisfaction score ($P = 0.002$). Furthermore, patients in the EA group were also more willing to repeat the procedure ($P = 0.05$). On the other hand, the endoscopists’ satisfaction score of the procedure were not different ($P = 0.110$).Conclusions:The study was terminated early as the results convincingly showed that the use of electroacupuncture significantly reduced discomfort during EUS, analgesic requirements and improved patient satisfaction. Further studies are required to study the mechanisms of action and how EA could be implemented to other endoscopic procedures.