After another tasty lunch at the Royal College of Physicians, we took up our seats to take part in the speaker forum. I was expecting plenty of questions to be put forward for discussion and was not disappointed. We had questions relating to the broad range of topics from the morning’s presentations; from purigenic signalling to the role of acupuncture in post-surgical pain to clinical application of auricular acupuncture and more.
Here are some highlights by topic:
Acupuncture and purigenic signalling
According to Professor Geoffrey Burnstock (GB), all cells release ATP. These include endothelial, skin, muscle, neural and immune (e.g mast) cells. ATP acts upon its various receptors creating a purigenic signalling effect, this may have positive effects at the various sites. In the correct doses, facilitated ATP release, for example in response to acupuncture, has been proposed to have a variety of therapeutic physiological effects. These range from autonomic modulation to analgesia, mainly due to its function as a co-transmitter.
Too much ATP however can promote pain via the activation of nociceptors as well as promoting sympathetically mediated pain for example. Another example is its role in regulating microglial cell function. These cells may be important in perpetuating chronic and inflammatory pain. Microglial cells release ATP which in turn activates or ‘winds up’ the microglial cells, a mechanism involving BDNF. GB explained that drugs are currently being developed to inhibit glial cell ATP receptor activity which may have a role in pain management.
Polymorphic variations of purinergic receptors may explain the variability in ATP based signalling effects. Personal genetic analysis may help determine which drugs based on purinergic signalling may work, and perhaps how well one might respond to acupuncture.
GB noted that a number of papers have described the effect of alcohol effects on purigenic signalling but none reported the effects of alcohol on acupuncture as far as he was aware.
GB asserts the role of ATP as a key acupuncture mechanism which further negates the notion that a sham technique will not have specific effects over and above placebo regardless of needle location.
Is acupuncture superior to manual techniques and exercise in promoting ATP release? The short answer according to GB is that acupuncture is not superior, all will promote the release of ATP and a subsequent purigenic signalling effect. We use acupuncture because we like to, however the release of this neurotransmitter is not exclusively an acupuncture response. Different forms of mechanical stimulation work just as well given similar neural pathways are activated.
Lastly, GB reflects on his purinergic hypothesis as being intriguing and ultimately correct. He went on to explain how in research much courage is needed to challenge established doctrines within a very conservative scientific community. Research which challenges conventional wisdom requires resilience, good judgement, and intuitive thinking; knowing when to stop and ask a different question. Above all passion is needed, you have to really want to do it and get an answer.
When treating with auricular acupuncture, according to TU there are no specific recommendations as to how long an indwelling needle may be left in situ. In his experience the longest duration was four weeks using fairly large diameter needles, this resulted in some minor skin lesions but no infection. As a result, TU prefers to leave indwelling needles in situ for up to a week with the patient instructed to remove the needles if any skin related issues occur. TU recalls one case of infection during the treatment of a patient with chronic knee pain. He suggests avoiding the use of indwelling needles when treating insulin dependent patients, those receiving radiotherapy or chemotherapy due to the possibility of reduced local perfusion, as well as those who are immunocompromised.
TU’s auricular acupuncture studies used verum points which have been shown to be effective based on previous studies, and tended to be standardised. He went on to suggest there may be some scope for individualisation within a defined acupuncture approach in future studies.
The close proximity of the verum auricular acupuncture points to the sham points in TU’s studies resulted in the ‘sham’ effect being questioned by a member of the audience. TU responded by acknowledging the methodological difficulties and mentioned his wish was to perform verum compared to no acupuncture or standard treatment as the basis for future effectiveness studies.
Barriers to use of acupuncture in the NHS
These range from general attitudinal, reluctance to allow the introduction of new procedures, to concerns about safety and patient welfare. CK admits she has the benefit of acupuncture already being established in her hospital and appreciates the challenges faced in certain NHS settings. Her advice, when trying to set up an acupuncture service, is to try and get as many advocates on board as possible within a team based approach.
The practitioner effect
Why do experienced practitioners observe a greater acupuncture effect? BH thinks this is likely due to how the experienced practitioner communicates with the patient, in that he or she is likely to convey more confidence resulting in a greater patient perceived sense of competence. TU suggests the effects are very psychological, which influence the patient and so the result. He was also alluding to the nonspecific effects relating to suggestion and expectation which of course influence not only acupuncture outcomes but outcomes in most other areas of medicine which involve interaction with a practitioner. The take home message is to be confident, and make sure the patient thinks you know what you are doing!
Acupuncture for analgesia after caesarean section
The options are to use acupuncture either pre operatively, pre operatively and post operatively, or postoperatively only. The rationale according to BH, who used a pre and post-operative needling approach in his RCT was to sensitise or upregulate the nervous system before the surgery, therefore making it easier to re-activate the analgesic pathways following. Whether or not postoperative needling only would have value was not discussed but should perhaps be considered.
That’s it for 2017, looking forward to next year!
By Simon Coghlan
- GB: Professor Geoffrey Burnstock
- TU: Professor Taras Usichenko
- BH: Dr. Berthold Henkel
- CK: Dr. Catharina Klausnitz