Characterization of De Qi with Electroacupuncture at Acupoints with Different Properties

OBJECTIVES: This study sought to explore the characteristics of de qi using electroacupuncture at acupoints with different properties in the meridian category, histological type, and nerve innervations. METHODS: Electroacupuncture was performed on 21 healthy volunteers at paired acupoints of ST36-GB34, CV4-CV12, ST36-ST28, PC6-PC7, and ST36-CV4. Upon acupuncture de qi, the intensities and the prevalence of individual sensations, sensation transmission, and the amplitude of electrical current were recorded. Chi-square, Fischer's exact test, Wilcoxon test, and two-sample paired t test were used to compare the components of de qi within each paired group. RESULTS: Overall intensities and prevalence of individual sensations are fullness, numbness, soreness, tingling, heaviness, pressure, dull pain, warmness, and coolness in decreasing order. No significant difference was found in the prevalence of needling sensations between the two paired points (p>0.05). However, significant intensity differences (p<0.05) were showed in soreness, fullness, and heaviness between ST36-ST28, in fullness and numbness between ST36-CV4, and in fullness between CV4-CV12. Tingling sensation was stronger than heaviness and pressure at acupoints PC6-PC7 and ST36 (as paired with CV4). Sharp pain occurred in 10/216 tests (4.63%). Sensation transmission occurred highly (77.78%) on participants, and sensations mostly propagate over one joint but no further than two joints. Overall electrical current was 2.35±0.07 mA (mean±standard error). No significant difference was found between paired acupoints for the distance of sensation transmission and the amplitude of electrical current. CONCLUSIONS: Fullness, numbness, and soreness were the most common and obvious sensations associated with electroacupuncture. The difference of sensation intensities may be associated with different nerve innervations.