NSS-2 BRIDGE Device in Post-Operative Pain Management

Overview

The current opioid epidemic has led to a renewed interest in exploring non-pharmacological techniques to treat post-operative pain. An increasing number of patients are suffering from the adverse effects of opioid use following surgery, including post-operative nausea and vomiting, respiratory depression, immunosuppression, constipation, and most recently, addiction. Although the risk of opioid addiction following surgery is recognized, the percentage of patients becoming addicted to opioids following surgery is not well understood. Therefore, in order to combat this growing health crisis at the ground level, it is incumbent upon the medical community to explore alternative methods of pain control to treat the surgical population in order to reduce the incidence of post-operative opioid addiction. Percutaneous Nerve Field Stimulation (PNFS) is one of these recognized methods that ongoing research has shown to be effective as a complementary method of pain management. While PNFS is not a novel concept, clinical indications of auricular field stimulation have been limited in the past due to requirement of bulky, stationary and non-disposable stimulators and electrodes. These technological limitations made it difficult to establish the real clinical potential of auricular stimulation for the perioperative management of pain in surgical patients, despite the demonstration that auriculotherapy has been shown to relieve pain in the postoperative setting. The NSS-2 BRIDGE is a battery operated and disposable percutaneous auricular nerve field stimulator (Innovative Health Solutions, Versailles, IN, USA), that was recently cleared by the FDA and assigned a Class II Risk Designation. The indication for the NSS-2 BRIDGE is for the treatment of clinical symptoms related to opioid consumption and opioid withdrawal. These symptoms include abdominal pain, anxiety and post-operative nausea and vomiting; conditions which are also present following major oncologic abdominal surgery. The use of the NSS-2 BRIDGE device has been demonstrated to provide significant analgesia in patients with abdominal pain syndrome, and clinical trials are ongoing to assess the benefit of this approach for post-operative pain management. As compared to the present use of opioids for perioperative pain management, the use of a complementary, non-pharmacologic approach offers the advantage of analgesia without the associated side effects.

Potential subjects (from both the prospective interventional and control groups) will be recruited in the pre-surgical clinic of the surgical oncology group at UPMC Shadyside once they are scheduled for major abdominal surgery. Patients will be asked for their interest in pursuing a research study that involves wearing a percutaneous, auricular field stimulator for five days as a supplementary method of post-operative pain control. Patients who agree to participate in the trial will sign an IRB approved Informed Consent Form. Once patient has signed the Informed Consent to participate in this pilot study, demographic information and medical history will be collected from each participant on the day of surgery. The NSS-2 BRIDGE device will be applied to the ear by Dr. Jacques Chelly or Research Coordinator Amy Monroe in the immediate post-operative setting (PACU), as Dr. Chelly and Amy Monroe have both completed the necessary training required by the company to apply the device. Rescue analgesia will be permitted as per the approved ERAS multi-modal anesthetic protocol, however, the patient will be made aware at the time of consent and throughout the trial that they can drop out of the study at any time if they do not like wearing the NSS- 2 BRIDGE device. Randomization of both groups will occur by assigning the participant a subject ID number, and this ID number will correspond to a treatment allocation based on a pre-designed randomization schema. This treatment allocation (intervention/control) will be contained in a sealed, opaque, envelope with the subject ID number that is designated on envelope. The master randomization list will be created and held by an independent data monitor who will both create and hold the master randomization list. The patient will be assessed 12, 24, 48, 72, 96 and 120 hours post-operatively to collect total opioid consumption, incidence of adverse events, and verbal pain scores. Additional data that will be collected includes total non-narcotic analgesic consumption, time to readiness for discharge from PACU, time to bowel movement, time to oral intake (liquid and regular diet), time to hospital discharge, intensive care unit (ICU) admission, readmission to the hospital, percentage of patients readmitted because of pain related issues, overall patient satisfaction, and patient satisfaction relating to pain management. When the patient is discharged from the hospital, they will be asked to complete a patient satisfaction survey. For patients discharged with the device attached, removal instructions and pre-paid return envelope will be given to patient to remove the device at 120 hours and send back to the hospital. The patient will be contacted 3 months post-operatively to again assess patient satisfaction with the pain management after surgery, and to assess functional recovery. Post-operative nausea and/or vomiting will be evaluated by nausea score (0-10). Frequency of emesis and rescue antiemetic requirement will be collected per the institution's standard of care and transcribed from the medical record by research staff. Standard opioid conversion table will be used to convert the oral and IV narcotic utilized by the patients to oral morphine equivalent doses (OME) for analysis purposes. Time to patient-controlled analgesia (PCA) initiation on the floor will also be measured, as well as total PCA hydromorphone consumption over the 120-hour postoperative period. Overall patient satisfaction and satisfaction of pain management during hospitalization will be measured by a numerical rating scale with 0- worst satisfaction and 10 being the best satisfaction. The patient satisfaction test will be administered by a member of the research team. Number of patients with unsatisfactory pain relief defined as average Numerical Rating Scale (NRS) more than 5 with or without requirement of IVPCA for pain relief during the first 120 hours postoperative period will be compared between the two groups and form the primary outcome for the study. Secondary outcome measures will include non-narcotic analgesic consumption, episodes of PONV, verbal pain scores, time to readiness for discharge from PACU, time to first bowel movement, time to oral intake (liquid and regular diet), time to hospital discharge, readmission to the hospital, percentage of patients readmitted because of pain related issues, functional recovery, overall patient satisfaction, and patient satisfaction relating to pain management. Overall patient satisfaction and satisfaction of pain management during hospitalization will be measured by a numerical rating scale with 0- worst satisfaction and 10 being the best satisfaction. This patient satisfaction score will administered by member of research team.