Effect of “needle sensation” and the real-time changes in autonomic nervous system activity during acupuncture analgesia, 2024, Zehua Liu et al

The pain treatment was a chilli extract applied to the lip for 15 minutes.

The sham acupuncture was at a site deemed inactive, and the skin was not broken. It looks as though only with the real acupuncture treatment was the needle 'lifted' and 'thrusted' and 'twirled'.

Of the 64 people who received the actual treatment, 2 were excluded from the study due to 'needle fainting'.

I'm not sure how the MASS works - there seems to be a whole lot of scales that are presumably averaged - so I think someone could report a 10 (unbearable) on 'sharp pain', but that could be diluted down by their score of a 2 (mild) for 'warmth' and 'heaviness'. In any case, the fact that two people fainted and the mean MASS scores at the 5 and 10 minute marks were 4.5 (moderate) means that there was significant pain caused by the treatment. This was not the case with the 'sham' and 'model' treatments.

It looks like the finding was that after 15 minutes of needling, there was some benefits to pain levels reported using a visual scale (a subjective measure) five minutes later, as compared to no needling (the model group), and to a lesser extent, a sham acupuncture group.

The study looks to have made some effort to make an effective control for the real treatment, but I imagine it was not impossible to tell if you were getting sham acupuncture. Participants were reported to be naive to acupuncture, the acupuncture was done with the arm through curtain so the participants couldn't see the treatment. If someone volunteered for an acupuncture study, probably they would have chatted with friends about what to expect before going to the clinic . The people doing the acupuncture were acupuncturists, and some of the institutions involved would benefit if a positive result was found.

Here's the reported pain levels from the chilli extract - Figure 5

That's not much difference, not for the pain of the acupuncture.


I think the increased improvement in subjective pain reported as relating to the chilli extract on the lip five minutes after the needling stops in the acupuncture treatment group could be dismissed as simply a placebo effect. In any case, the prospect of causing pain for 15 minutes to distract from pain, and for that distraction to be almost inconsequential and only last 5 minutes doesn't sound that useful.

There are still the supposed measures of autonomic function to look at.

 

Just a word on the effectiveness rating which was headlined in the abstract:

Those percentages sound useful. However, effectiveness was measured by whether the pain rating at Time 1 (which was when the chilli extract was applied to the lip and when the acupuncture treatment was started) was greater than any of the pain ratings at times 3, 4 or 5 (5 being 5 minutes after the chilli extract patch was removed and the acupuncture stopped). Therefore, a pain rating at one of the later times only has to be fractionally lower than the rating at time 1 to produce a positive effectiveness outcome. And Figure 5 shown above indicates that this was the case, we are only talking fractionally lower - there was no miraculous decrease in pain, certainly not enough to suggest that acupuncture is an effective anaesthesia.