Safety of different distances in warm-needling moxibustion: An exploratory trial

The moxibustion distance is a critical component that influences the thermal effects of warm-needling moxibustion therapy. Clinical recommendations regarding moxibustion distance are based on indirect inference from mild moxibustion studies due to the lack of relevant trials on the impact of moxibustion distance. Given the current understanding, we explored the influence of different moxibustion distances on thermal effects to establish a safety threshold for moxibustion distance and to guide the setting of moxibustion distance parameters in warm-needling moxibustion therapy. In this single-center randomized controlled trial, participants were randomly assigned to receive 3.0 cm distance warm-needling moxibustion and 3.5 cm distance warm-needling moxibustion at right weizhong (BL40), zhongwan (RN12), left zusanli (ST36) and right shenshu (BL23). The primary outcome was the response rate in individuals, which is the proportion of participants who experienced burning pain one or more times during the warm-needling moxibustion intervention process on four acupoints. The secondary outcomes included the highest temperature and the changed temperature from baseline at warm-needling moxibustion needle was removed immediately. 60 participants were randomly assigned into the 3.0 cm-distance group and 3.5 cm-distance group. The response rate in individuals at the 3.0 cm-distance group was significantly higher than that in 3.5 cm-distance group ( P < 0.001). The highest temperature of participants with burning pain was significantly higher than that with no burning pain (all P < 0.001). There is a statistical difference between 3.0 cm-distance with no burning pain and 3.5 cm-distance with no burning pain in BL40 ( P = 0.02). There was no significant difference in changed temperature from baseline between different moxibustion distance groups in participants with no burning pain. Different application distances in warm-needling moxibustion can affect its thermal effects and safety. A 3.5 cm-distance may provide an optimal balance between thermal efficacy and safety in individuals with normal thermosensitivity, though further confirmation is warranted.