Reduction in postoperative opioid requirement associated with use of the NSS-2® Bridge device, a disposable auriculo-nerve field stimulator, and factors affecting the response in cancer patients undergoing abdominal surgical procedures

ABSTRACT Objective Determine the effect on opioid use after surgery with use of the NSS-2® Bridge device (NBD ® ) as a field nerve stimulator of the nerves innervating the ear for 5 days. Methods This was a prospective, randomized, double-blind, placebo-controlled trial investigating the effectiveness of the NBD ® in reducing opioid (expressed as oral morphine equivalent; OME, mg) requirement in subjects undergoing abdominal surgery for cancer. A total of 53 subjects randomly assigned to either an active NBD ® group or placebo group were included in the analysis. Secondary endpoints included pain using a verbal analogue scale (VAS, 0 = no pain to 10 = worst possible pain), time to ambulation, oral intake, first bowel movement, discharge from the hospital, and tolerability of the NBD ® . Lastly, functional recovery rated using the 12-item Short Form Survey (SF12) assessed at three months. Results Use of the NBD® resulted in a 26% overall reduction in OME with no difference in pain level expressed as the area under the curve between postoperative day 1 to 5. respectively). This overall reduction accounts for a 6% reduction in OME in the patients undergoing laparoscopic surgery and a 39% reduction in OME and 25% reduction in pain in patients undergoing open surgery. The tolerability of the device was reported as excellent. Conclusions Cancer patients have been identified as a population at risk of developing opioid use disorders. This prospective, randomized, double-blind, placebo-controlled study, demonstrated that NBD® may be an effective alternative to the use of opioid postoperatively in patients undergoing abdominal surgery for cancer, especially in especially in patients undergoing open surgery and in elderly.