title: Impact of surgical intervention and postoperative pain on electrical skin resistance at acupuncture points: an exploratory study.
abstract: OBJECTIVE
  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 defined 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 significantly 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 influence of postoperative pain intensity was also assessed.
  
  
  RESULTS
  Group comparison showed no significant differences for ST38. The ESRMs at GB34 had a significantly 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Multidisciplinary Pain Centre, Department of Anaesthesiology, University of Munich, Germany. sybille.kramer@med.uni-muenchen.de
authors.forename: Sybille
authors.initials: S
authors.lastname: Kramer
authors.forename: Daniela
authors.initials: D
authors.lastname: Zaps
authors.forename: Dieter F
authors.initials: DF
authors.lastname: Kutz
authors.forename: Bernhard
authors.initials: B
authors.lastname: Wiegele
authors.forename: Florian P
authors.initials: FP
authors.lastname: Kolb
authors.forename: Katrin
authors.initials: K
authors.lastname: Zimmer
authors.forename: Lukas
authors.initials: L
authors.lastname: Lehmeyer
authors.forename: Johannes
authors.initials: J
authors.lastname: Fleckenstein
authors.forename: Ursula
authors.initials: U
authors.lastname: Becker
authors.forename: Philip M
authors.initials: PM
authors.lastname: Lang
authors.forename: Dominik
authors.initials: D
authors.lastname: Irnich
mesh_terms: D015669:Acupuncture Points; D015670:Acupuncture Therapy; D000328:Adult; D000368:Aged; D062109:Dermatologic Surgical Procedures; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000503:physiopathology* / Q000628:therapy; D012867:Skin / Q000737:chemistry*; D012879:Skin Physiological Phenomena