Effect of 2-Hz Electroacupuncture Stimulation on Respiratory Function: A Randomized Controlled Trial

Objective: The autonomic nervous system is involved in the regulation of airway smooth muscle. This study examined the effect of acupuncture stimulation in the vicinity of the cervical-sympathetic ganglion on respiratory function in humans. Materials and Methods: Twenty-four healthy adults (19 males and 5 females) were randomly assigned to a no-treatment group, a leave-needle group, and an electroacupuncture (EA) group in a crossover trial. In all groups, respiratory function was initially tested. In both acupuncture groups, after 5 minutes of rest, a 5-minute acupuncture stimulus was delivered, followed by 5 minutes of rest. Thereafter, respiratory function was again tested in all groups. Acupuncture was delivered in the vicinity of the cervical ganglia at the height of the sixth cervical vertebra on the left side and the vertebral artery node; the EA stimulus was set to 2 Hz, and the stimulation intensity was set to a level at which no pain was felt by the participants. Results: The EA group had significant increases in peak expiratory flow (PEF) and vital capacity (VC) after the intervention, compared to before intervention. Additionally, the EA group had significant increases in these parameters, compared to the no-treatment group. Conclusions: These results indicated that stimulation with 2-Hz EA in the vicinity of the cervical-sympathetic trunk causes an increase in PEF and VC, and increased bronchial dilation.