Patient-Administered Transcutaneous Electrical Nerve Stimulation for Postoperative Pain Control After Laparoscopic Cholecystectomy: A Randomized, Sham-Controlled Feasibility Trial.

OBJECTIVES: Transcutaneous electrical nerve stimulation (TENS) is a noninvasive analgesic neurostimulation modality. Difficulties in clinical trial blinding and therapy administration have limited conclusions of previous trials. The aims of this study were to first investigate the feasibility and acceptability of patient-administered TENS after surgery, and second, the feasibility of using sub-sensory TENS as a proxy sham group for patient-blinding. MATERIALS AND METHODS: Over a four-month period, patients undergoing laparoscopic cholecystectomy at a single center were randomized to receive maximally tolerable high-intensity (HI) TENS or sub-sensory low-intensity (LI) TENS. Patients and outcome assessors were blinded. Primary outcomes were the feasibility, tolerability, and acceptability of patient self-administered TENS, measured by patient-reported outcomes, and the strength of patient-blinding, measured using the James Blinding Index (JBI). Secondary outcomes explored clinical recovery and analgesic efficacy. RESULTS: Nineteen patients were screened for inclusion; ten patients were randomized and completed the feasibility study. TENS therapy was variably utilized (median duration of TENS 5.3 hours/day [IQR: 4.1-6.9]). The JBI was 0.7, indicating a strong strength of blinding. Majority of patients found the TENS unit easy to use (90%) and were confident with self-administration (100%). No patients experienced adverse effects of TENS use. CONCLUSIONS: Patient-administered TENS is safe and acceptable. Future studies may use sub-sensory TENS as a proxy sham control to more reliably blind patients. A larger, double-blinded RCT employing these techniques is now needed to determine the analgesic efficacy of TENS in an enhanced recovery setting, and its potential to reduce opiate usage.