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.
Full Text
The Full Text of this article is available as a PDF (121.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Alton E. W., Batten J., Hodson M., Wallwork J., Higenbottam T., Geddes D. M. Absence of electrochemical defect of cystic fibrosis in transplanted lung. Lancet. 1987 May 2;1(8540):1026–1026. doi: 10.1016/s0140-6736(87)92285-9. [DOI] [PubMed] [Google Scholar]
- Bland J. M., Altman D. G. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet. 1986 Feb 8;1(8476):307–310. [PubMed] [Google Scholar]
- Boucher R. C. Human airway ion transport. Part one. Am J Respir Crit Care Med. 1994 Jul;150(1):271–281. doi: 10.1164/ajrccm.150.1.8025763. [DOI] [PubMed] [Google Scholar]
- Höfmann T., Bohmer O., Hüls G., Terbrack H. G., Bittner P., Klingmüller V., Heerd E., Lindemann H. Conventional and modified nasal potential-difference measurement in cystic fibrosis. Am J Respir Crit Care Med. 1997 Jun;155(6):1908–1913. doi: 10.1164/ajrccm.155.6.9196094. [DOI] [PubMed] [Google Scholar]
- Knowles M. R., Buntin W. H., Bromberg P. A., Gatzy J. T., Boucher R. C. Measurements of transepithelial electric potential differences in the trachea and bronchi of human subjects in vivo. Am Rev Respir Dis. 1982 Jul;126(1):108–112. doi: 10.1164/arrd.1982.126.1.108. [DOI] [PubMed] [Google Scholar]
- Knowles M. R., Carson J. L., Collier A. M., Gatzy J. T., Boucher R. C. Measurements of nasal transepithelial electric potential differences in normal human subjects in vivo. Am Rev Respir Dis. 1981 Oct;124(4):484–490. doi: 10.1164/arrd.1981.124.4.484. [DOI] [PubMed] [Google Scholar]
- Knowles M., Gatzy J., Boucher R. Increased bioelectric potential difference across respiratory epithelia in cystic fibrosis. N Engl J Med. 1981 Dec 17;305(25):1489–1495. doi: 10.1056/NEJM198112173052502. [DOI] [PubMed] [Google Scholar]
- Mialon P., Charfi R., Regnard J., Lockhart A., Dinh-Xuan A. T. Locally deposited but not inhaled frusemide reduces nasal potential difference in healthy subjects. Eur J Clin Pharmacol. 1993;45(4):347–351. doi: 10.1007/BF00265953. [DOI] [PubMed] [Google Scholar]
- Wood A., Higenbottam T., Jackson M., Scott J., Stewart S., Wallwork J. Airway mucosal bioelectric potential difference in cystic fibrosis after lung transplantation. Am Rev Respir Dis. 1989 Dec;140(6):1645–1649. doi: 10.1164/ajrccm/140.6.1645. [DOI] [PubMed] [Google Scholar]