Effectiveness of Transcutaneous Auricular Vagal Nerve Stimulation on Alleviating Postoperative Pain Following Thoracoscopic Lobectomy: A participant- and assessor-blinded, Randomized Controlled Trial.

OBJECTIVES

This study aimed to investigate the effectiveness of transcutaneous auricular vagal nerve stimulation (taVNS) in alleviating postoperative pain following thoracoscopic lobectomy.

METHODS

In this randomized controlled trial, 70 adult patients were randomly assigned in a 1:1 ratio to receive either active or sham taVNS. Stimulation was initiated in the preoperative room, maintained throughout surgery, and discontinued after extubation in the post-anesthesia care unit, at which point the device was removed. Additional 2-hour sessions were conducted each morning on postoperative days 1 and 2. Patient-controlled intravenous analgesia and serratus anterior plane block were provided to all the patients. The primary outcome was sufentanil consumption during the first 24 hours after surgery.

RESULTS

A total of 67 participants completed the study. Sufentanil consumption showed no statistically significant difference between the active group (33 ± 13 μg) and the sham group (32 ± 9 μg) (mean difference=1.20, 95% confidence interval=-4.23 to 6.63, P-value=0.661). Compared to the sham group, taVNS produced a statistically significant reduction in the numerical rating scale for resting pain (P-value=0.001) and deep breathing pain (P-value<0.001) postoperatively. taVNS also significantly reduced the incidence of rebound pain (58% vs. 18%; P-value=0.001) and chronic postsurgical pain at three months (27% vs. 6%; P-value=0.018).

DISCUSSION

taVNS did not reduce postoperative opioid consumption but alleviated acute postoperative pain, lowered the incidence of rebound pain and chronic postsurgical pain. These preliminary findings have uncertain clinical significance and require further investigation.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2400081062).