title: Silver/silver chloride electrodes for measurement of potential difference in human bronchi.
abstract: BACKGROUND
  An easy and reliable method to measure potential difference (PD) in the lower airways would be of interest in the field of cystic fibrosis. We have developed silver/silver chloride (Ag/AgCl) electrodes to measure PD in the lower airways.
  
  
  METHODS
  To validate this technique the nasal PD measured with Ag/AgCl electrodes and with conventional perfused electrodes was compared in 16 patients. The range of PD measured with Ag/AgCl electrodes in the lower airways during fibreoptic bronchoscopy was determined in 14 adult patients and in nine the reproducibility of this technique was examined.
  
  
  RESULTS
  Nasal PD values measured with Ag/AgCl and perfused electrodes were highly correlated (r = 0.985, p < 0.0001) and the limits of agreement (mean +/- 2SD of the difference) between the two methods were -1.91 mV and 1.53 mV. In the lower airways a progressive and slight decrease in PD values with decreasing airway diameter was observed in most patients. The mean (2SD) of the differences between the two tracheal measurements was 0.21 (1.73) mV.
  
  
  CONCLUSIONS
  The use of Ag/AgCl electrodes gives a reliable and reproducible measurement of PD in the lower airways in humans.
authors: Department of Respiratory Physiology, Cochin Hospital, René Descartes University, Paris, France.
authors: I
authors: I
authors: Fajac
authors: J
authors: J
authors: Lacronique
authors: A
authors: A
authors: Lockhart
authors: J
authors: J
authors: Dall'Ava-Santucci
authors: D J
authors: DJ
authors: Dusser
mesh_terms: D015374:Biosensing Techniques; D001980:Bronchi / Q000503:physiopathology*; D003550:Cystic Fibrosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015336:Molecular Probe Techniques