Neuropathic pain(NP)is directly caused by lesions or diseases of the somatosensory system.It can be attributed to a variety of causes and has a complex pathological mechanism.Purinergic P2X receptors play a critical role in NP.P2X receptors will be activated by the extracellular adenosine triphosphate(ATP)to mediate the pain when the tissue is damaged.In vertebrates,there are 7 subtypes of P2X receptors(P2X1-7)encoded by genes,among which the receptors of P2X3,P2X4,and P2X7 are closely related to NP.Acupuncture produces good therapeutic efficacy on NP.To explore the mechanism of purinergic signaling involved in acupuncture analgesia,a review of the actions of P2X3,P2X4,and P2X7 receptors in acupuncture for NP was conducted.The P2X3 receptor is specifically expressed in small-and moderate-sized neurons in the dorsal root ganglion of the primary afferent nerve and trigeminal ganglion.Acupuncture can directly mediate analgesia by down-regulating the expression of P2X3 receptor in neurons.P2X4 and P2X7 receptors mainly exist in the spinal microglia.Acupuncture can inhibit the nociceptive transmission of substantia gelatinosa neurons by regulating P2X4 receptor in spinal microglia.Moreover,acupuncture may alleviate NP by inhibiting the secretion of inflammatory factors by reducing P2X7 receptor in the spinal microglia.

Critical ultrasonography(CUS) is different from the traditional diagnostic ultrasound,the examiner and interpreter of the image are critical care medicine physicians.The core content of CUS is to evaluate the pathophysiological changes of organs and systems and etiology changes.With the idea of critical care medicine as the soul,it can integrate the above information and clinical information,bedside real-time diagnosis and titration treatment,and evaluate the therapeutic effect so as to improve the outcome.CUS is a traditional technique which is applied as a new application method.The consensus of experts on critical ultrasonography in China released in 2016 put forward consensus suggestions on the concept,implementation and application of CUS.It should be further emphasized that the accurate and objective assessment and implementation of CUS requires the standardization of ultrasound image acquisition and the need to establish a CUS procedure.At the same time,the standardized training for CUS accepted by critical care medicine physicians requires the application of technical specifications,and the establishment of technical specifications is the basis for the quality control and continuous improvement of CUS.Chinese Critical Ultrasound Study Group and Critical Hemodynamic Therapy Collabration Group,based on the rich experience of clinical practice in critical care and research,combined with the essence of CUS,to learn the traditional ultrasonic essence,established the clinical application technical specifications of CUS,including in five parts:basic view and relevant indicators to obtain in CUS;basic norms for viscera organ assessment and special assessment;standardized processes and systematic inspection programs;examples of CUS applications;CUS training and the application of qualification certification.The establishment of applied technology standard is helpful for standardized training and clinical correct implementation.It is helpful for clinical evaluation and correct guidance treatment,and is also helpful for quality control and continuous improvement of CUS application.