Abstract Gwan Kho

Evidence based acupuncture analgesia in the operating theater:from needle insertion to the inhibition of nociception

The treatment of complaints and illnesses with needles (Zhenjiu) is part of the traditional Chinese medicine (TCM). TCM assumes that there is a circulation of energy (qi) within the body. Qi flows along imaginary lines, the so-called meridians, which link acupuncture points
with similar properties. In the interest of health, an unimpeded flow of qi is necessary.
According to TCM, conditions or illnesses result from an interruption of the flow of qi in the body, making a balanced of the qi circulation no longer possible. The treatment consists of attempting to end the situation in places where the flow of qi is impeded. Much research has been conducted into the apparently simple working hypothesis of acupuncture in recent decades, both fundamental and clinical. The use of acupuncture as an anaesthetic has challenged the scientific community which in turn triggered and accelerated basic pain and analgesic research to the progress and achievements of the past decades.
The mechanisms of acupuncture analgesia are brought about by changes in neuronal activity at different levels of the central nervous system following certain types of afferent discharges. Segmental and non-segmental pain inhibitory systems can be selectively activated depending
on the stimulation variables (low frequency stimulation releases enkephalins and endorphins, while high frequency stimulation releases mainly dynorphins) and the location of the chosen points. Both opioid and non-opioid analgesia systems are involved in mediating acupuncture
analgesia. Following needle insertion and stimulation, the peripheral afferent pathways carrying acupuncture impulses are activated.          They are transmitted via the spinal cord anterolateral tract to reach the hypothalamus-pituitary system, which releases endorphins into blood and cerebrospinal fluid, and the periaqueductal grey matter. Two actions develop then. It releases endorphins to suppress the transmission of nociceptive information and it triggers the raphe nuclei, leading to activate the decending inhibitory system. This results in an inhibition of the
dorsal horn cells receiving nociceptive impulses. Analgesia elicited by acupuncture occurs as a result of activation of the spinal cord, the
hypothalamus-pituitary system, the periaqueductal grey matter leading to an inhibition of incoming nociception.