Auricular field nerve stimulation using the NSS-2 BRIDGE device as an alternative to opioids following kidney donor surgery.

Objectives: The purpose of this study was to investigate the role that the NSS-2 BRIDGE device, an auricular field nerve stimulator, may play in reducing opioid requirement and pain in kidney donor surgery. It was not a randomized study. Electrophysiologic studies have demonstrated that the stimulation of the cranial nerves produced by the NSS-2 BRIDGE device modulates the ascending/descending spinal pain pathways, especially at the level of the limbic system.

Methods: The design compared the effects of the NSS-2 BRIDGE device (NSS 2-BRIDGE device group; n=10) to a control group (n=10). In both groups, the surgery was performed using the same standard enhanced recovery after surgery protocol based on the use of a multimodal analgesic approach. For the active treatment group, the NSS-2 BRIDGE device was placed in the post anesthesia care unit. The primary endpoint was opioid requirement (oral morphine equivalent, OME in mg) at 24 h post-surgery. Secondary endpoints included pain (0-10), at 24 and 48 h, time to discharge from the recovery room, incidence of post-operative nausea and vomiting at 24 h, time to oral intake, time to ambulation, and time to discharge from the hospital. Data was analyzed using unpaired t-test and presented as mean ± standard deviation.

Results: Compared to control, the use of the NSS-2 BRIDGE was associated with a 75.4% reduction in OME (33.6 vs. 8.3 mg; p=0.03) and 41.5% reduction in pain (5 vs. 3.28; p=0.06) at 24 h and a 73.3% difference in pain at 48 h (1.6 ± 1.6 vs. 6.0 ± 2.8; p=0.0004). There was no difference in non-opioid analgesics administration between groups.

Conclusions: The tolerability of NSS-2 BRIDGE device was reported by most to be excellent. This study suggests that the NSS-2 BRIDGE device may represent a complementary approach for controlling postoperative opioid consumption and pain in patients undergoing kidney donation.