Effect of Transcutaneous Electrical Nerve Stimulation Based on Wrist-ankle Acupuncture Theory on Postoperative Pain After Video-assisted Thoracoscopic Surgery

Patients assigned to the TENS-WAA group will receive transcutaneous electrical nerve stimulation based on Wrist-Ankle Acupuncture theory for a duration of 30 minutes after anesthesia induction, as well as at 8 hours and 24 hours postoperatively. According to the principles of WAA, two pairs of TENS-WAA (Wuxi Jiajian Medical Device Co., Ltd.) electrode pads will be placed on the upper area 2 and 3 with the skin of the treatment area exposed, and the upper and lower juxtaposition method will be adopted. Upper area 2 is at the middle of the palmar side of the forearm, between the palmaris longus and flexor carpi radialis. Upper area 3 is between the edge of the radius and the radial artery. Stimulation parameters of TENS-WAA are alternating dense-disperse wave with a frequency of 2Hz and a pulse width of 200μs, and a frequency of 100Hz with a pulse width of 150μs, alternating every 3 seconds ，intensity required to reach the maximum tolerable level without causing pain.

Patients assigned to the sham TENS-WAA group will receive sham stimulation for a duration of 30 minutes after anesthesia induction, as well as at 8 hours and 24 hours postoperatively. Researchers will attach the electrode patches at the same location, set the parameters to the same frequency, pulse width, and minimum current intensity as the TENS-WAA group, but do not activate the device, leaving it in place for 30 minutes at each time point.