Deqi sensation between the acupuncture-experienced and the naïve: a Korean study II.
Previous experience of acupuncture is believed to affect people's expectation of future treatments. Therefore, subjects who have had acupuncture are generally excluded from sham-controlled acupuncture clinical trials. However, this assumption has not been proven, but just accepted because of the lack of evidence to the contrary. To investigate the difference in frequency and intensity of acupuncture sensation between subjects who have had acupuncture and those who have not, 36 acupuncture-experienced subjects were invited to take part in the study. After informed consent was obtained, participants were asked to complete the acupuncture sensation scale (ASS) according to what they expected needling to feel like. The needling was done at the left Hegu (LI 4) point and consisted of insertion, stimulation for 30 seconds and removal. After needling, the subjects were asked to complete the same ASS according to what they actually experienced. Adverse events were monitored. The frequency of each sensation expected and experienced, as well as acupuncture sensation scores were compared. More than 60% of the subjects expected to feel sensations of penetrating (87.6% to 100%), aching (71.2% to 95.5%), tingling (87.6% to 100%), pricking (79.7% to 99.2%) and throbbing (64.2% to 91.4%). In fact, the subjects experienced sharp (60.9% to 89.1%), intense (60.9% to 89.1%), radiating (71.2% to 95.5%) and heavy (74.8% to 97.4%) sensations just as much. The subjects expected more hurting (p = 0.001), tingling (p < 0.001), pricking (p = 0.010), stinging (p = 0.012), burning (p = 0.001) and pulsing (p = 0.009) than they experienced, while more heaviness (p = 0.011) was experienced than expected. The same outcome measures were also compared between experienced and naive groups. Apart from the fact that the acupuncture-experienced participants expected to feel pricking (p = 0.030) and stinging (p = 0.002), and experienced hurting (p = 0.022) and stinging (p = 0.028) significantly less than those who had not had acupuncture before, there was no significant difference between first time and experienced subjects. The results indicate that previous experience does not affect the people's expectation and does not hinder people from experiencing Deqi. In addition, a constellation of Deqi-related acupuncture-specific sensations is more than just a general pain intensity dimension, which requires a biochemical and physiological exploration.