Impact of Surgical Intervention and Postoperative Pain on Electrical Skin Resistance at Acupuncture Points: An Exploratory Study

Abstract

Objectives One theory about acupuncture suggests that pathological processes can cause measurable changes in electrical skin resistance (ESR) at acupuncture points (APs). Although the theory has yet to be proven, ESR measurements (ESRMs) form a frequently used part of contemporary acupuncture. The aim of this study was to test the so-called 'electrical responsiveness' of APs in the setting of a defi ned operative trauma. Methods ESRMs (n=424) were performed at the APs and surrounding skin of GB34 and ST38 in 163 participants using an impedance meter array developed for the purpose of ESRMs. For each group the percentage of measurements with a signifi cantly different ESR between the APs and the surrounding skin was calculated and compared with each other. Measurements of four groups were compared: healthy control subjects (n=30) and patients after ophthalmic (n=29), hip (n=42) and shoulder (n=30) surgery. The infl uence of postoperative pain intensity was also assessed. Results Group comparison showed no signifi cant differences for ST38. The ESRMs at GB34 had a signifi cantly higher percentage of measurements with an increased ESR after ophthalmic (23.2%) and hip (22.2%) surgery, but not after shoulder surgery (7.5%). Subgroup analysis showed that an increase in pain intensity tended to lead to a decrease in the number of APs with ESR changes. Conclusion These results suggest that reactive changes in ESR at APs might exist. Pain and alertness seem to have an impact on ESR at APs. However, the current data do not allow for conclusions to be drawn concerning the clinical use of ESRMs. INTRODUCTIONAcupuncture treatment is gaining in importance with a variety of studies confi rming its effi cacy in the treatment of various disorders. However, while evidence for the clinical efficacy of acupuncture is growing, questions are being raised concerning the specifi city of acupuncture points (APs).3 4 In order to increase the general acceptance of acupuncture, a better understanding of how APs and meridians function is needed.One theory about the specifi c nature of APs suggests that electrical skin resistance (ESR) is different from the surrounding area, [5][6][7] and that a change in the ESR at an AP can be the refl ection of a pathophysiological condition of the patient.8 9 Based on this assumption of an 'electrical responsiveness' of APs, commercially available devices for electrodermal testing have been developed for acupuncture point location as well as for use as diagnostic and therapeutic tools.10 11 Electrical skin resistance measurements (ESRMs) have been established as an integral part of contemporary acupuncture.5 However, the scientifi c support for an electrodermal distinctiveness of APs is controversial, 12 and there is even less evidence for the electrical responsiveness of APs. 5 13-15 ESRMs have proved diffi cult to verify due to their rapid variability and variations in measurement techniques. 16 In this investigation we used a method that minimises the infl uence of typical disturbances.17 I...

Neuropeptides SP and CGRP Underlie the Electrical Properties of Acupoints

“…In addition, the acupoints with high conductance in IMH rats but not naïve rats showed higher neurogenic inflammation and plasma extravasation than those of naïve rats (Figures 3G,H). Our hypothesis is further supported by another study showing that more significant changes in skin impedance at acupoint GB34 were observed in patients that had undergone surgery than in healthy subjects (Kramer et al, 2012). Importantly, previous studies point out that the precision of skin conductance measurements can be influenced by numerous factors such as skin dryness, skin thickness, size of the sensing electrode, pressure applied on the electrode, interelectrode distance, room temperature, and humidity (Ahn and Martinsen, 2007).…”

Investigation of the Electrical Impedance of Acupuncture Points and Non-Acupuncture Points before and after Acupuncture, using a Four-Electrode Device

“…It has been shown that physical and psychological conditions alter the electrical impedance of APs. 22 If acupuncture alters the electrical impedance of APs and meridians, it is possible that the affect of acupuncture on improving medical conditions can be explained by this theory.…”