Electroanalgesia: does it have a place in the routine management of acute and chronic pain?

Abstract

he role of nonpharmacologic analgesic modali-ties in the treatment of chronic pain syndromeshas long been questioned by medical practitio-ners because of a lack of adequately powered, pro-spective, randomized, double-blind sham-controlledstudies supporting their use in clinical practice (1–3).According to Smith et al. (1) most valid trials withacupuncture for chronic back and neck pain “tendedto be negative.” Interestingly, the authors of this sys-tematic review drew their “own conclusions(positive/negative)” based on their interpretation ofthese data. The article by Sator-Katzenschlager et al.(4) in the current issue of the journal describing aprospective, randomized sham-controlled study in-volving auricular acupuncture contributes to thegrowing body of scientific data supporting the use ofelectroanalgesic modalities in the management ofchronic low back pain (CLBP) (5–11).Analogous to earlier sham-controlled studies in-volving the use of percutaneous electrical nerve stim-ulation in the short-term management of CLBP (5–9),Sator-Katzenschlager found significant benefits ofelectro- (versus manual) acupuncture with respect tolower pain scores, improved “sense of well-being,”physical activity, and quality of sleep, and a reducedneed for oral analgesic medication (4). The currentinvestigation extends these earlier studies by alsoevaluating the longer-term benefits of electroanalgesiain the CLBP population. Of significant importancefrom the societal perspective, the CLBP patients re-ceiving electrostimulation were able to return to full-time work earlier as a result of their improved qualityof life. In a placebo-controlled study, Carlsson andSjolund (10) also suggested that electroacupuncturehas long-term beneficial effects in patients with CLBP.The study by Sator-Katzenschlager et al. (4) furtherdocuments the advantage of direct electrical (versusmechanical) needle stimulation in enhancing the anal-gesic benefits of acupuncture in patients with CLBP.In patients with acute pain, the intensity of the elec-trical stimulus was one of the primary determinants ofits analgesic efficacy (12). Interestingly, well controlledstudies involving the use of manual intradermal acu-puncture needles have also demonstrated impressivebenefits in the perioperative setting (13). Although thecurrent study involved the use of an auricular acu-puncture point, it is possible that similar results couldhave been achieved with electrical stimulation at otheracupoints (14), and/or specific dermatomes (5–9) cor-responding to the patient’s pain symptoms. In fact, ithas been demonstrated, using an acute pain model,that identical analgesic benefits can be achieved bystimulating at either an acupoint or the correspondingdermatomal levels (14).One of the major benefits of the auricular acupunc-ture device relates to its small size and the ability ofthe therapy to be administered on an ambulatory ba-sis, obviating the need for frequent clinic visits toreceive treatments. Comparative studies are needed toevaluate efficacy of transcutaneous electrical stimula-tion of the auricular acupuncture point (15) and thepercutaneous auricular electroacupuncture techniqueutilized in the study by Sator-Katzenschlager et al. (4).It will also be important to determine how long thebeneficial effects of auricular acupuncture persist afterthe therapy is discontinued.Further research is clearly needed to establish therole of simple electroanalgesic techniques such as au-ricular acupuncture and percutaneous neuromodula-tion therapy in the multimodal management of acute(15), subacute (16), and chronic pain syndromes (4–11)as well as for treating more serious medical conditions(17). Although auricular acupuncture has been widelyused to treat both cocaine and alcohol addiction, re-cently published randomized, controlled clinical trials